[Federal Register Volume 79, Number 37 (Tuesday, February 25, 2014)]
[Rules and Regulations]
[Pages 10353-10365]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-03976]



[[Page 10353]]

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DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration

21 CFR Part 179

[Docket No. FDA-1999-F-2405 (formerly 1999F-5522)]


Irradiation in the Production, Processing, and Handling of Food

AGENCY: Food and Drug Administration, HHS.

ACTION: Final rule; denial of request for a stay of effective date and 
for a hearing; response to objections; confirmation of effective date.

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SUMMARY: The Food and Drug Administration (FDA or we) is responding to 
objections and is denying requests that it received for a hearing on 
the final rule that appeared in the Federal Register of August 22, 2008 
(73 FR 49593), and that amended the food additive regulations to 
provide for the safe use of ionizing radiation for control of food-
borne pathogens and extension of shelf life in fresh iceberg lettuce 
and fresh spinach. After reviewing objections to the final rule and 
requests for a hearing, we have concluded that the objections do not 
raise issues of material fact that justify a hearing or otherwise 
provide a basis for revoking or modifying the amendment to the 
regulation. We are denying the request for a stay of the effective date 
of the amendment to the food additive regulations. We are also 
confirming the effective date of August 22, 2008, for the final rule.

DATES: Effective date of final rule published in the Federal Register 
of August 22, 2008 (73 FR 49593) confirmed: August 22, 2008.

FOR FURTHER INFORMATION CONTACT: Teresa A. Croce, Center for Food 
Safety and Applied Nutrition (HFS-265), Food and Drug Administration, 
5100 Paint Branch Pkwy., College Park, MD 20740-3835, 240-402-1281.

SUPPLEMENTARY INFORMATION:

I. Introduction

    In a notice published in the Federal Register of January 5, 2000 
(65 FR 493), which was subsequently amended May 10, 2001 (66 FR 23943), 
we announced that a food additive petition (FAP 9M4697), had been filed 
by the National Food Processors Association (now merged into the 
Grocery Manufacturers Association) on behalf of The Food Irradiation 
Coalition, 1350 I St. NW., Suite 300, Washington, DC 20005 
(petitioner). The petition proposed to amend the food additive 
regulations in part 179, Irradiation in the Production, Processing and 
Handling of Food (21 CFR part 179), to provide for the safe use of 
ionizing radiation for control of food-borne pathogens and extension of 
shelf life in a variety of human foods up to a maximum irradiation dose 
of 4.5 kiloGray (kGy) for non-frozen and non-dry products, and 10.0 kGy 
for frozen or dry products, including: (1) Pre-processed meat and 
poultry; (2) both raw and pre-processed vegetables, fruits, and other 
agricultural products of plant origin; (3) and certain multi-ingredient 
food products containing cooked or uncooked meat or poultry. 
Subsequently, in a letter dated December 4, 2007, the petitioner 
amended the petition to request a response to part of the original 
request while the remainder of the request would remain under review. 
Specifically, the petitioner requested a response regarding amending 
the food additive regulations to provide for the safe use of ionizing 
radiation for control of food-borne pathogens and extension of shelf 
life in fresh iceberg lettuce and fresh spinach up to a maximum dose of 
4.0 kGy. In response to this request, we issued a final rule in the 
Federal Register of August 22, 2008 (73 FR 49593), permitting the 
irradiation of fresh iceberg lettuce and fresh spinach (hereafter 
referred to as ``fresh lettuce and fresh spinach'') for control of 
food-borne pathogens and extension of shelf life up to a maximum dose 
of 4.0 kGy. We based our decision on data in the petition and in our 
files. In the preamble to the final rule, we outlined the basis for our 
decision and stated that objections to the final rule and requests for 
a hearing were due within 30 days of the publication date (i.e., by 
September 22, 2008).

II. Objections, Requests for a Hearing, and Request for a Stay of 
Effective Date

    Section 409(f)(1) of the Federal Food, Drug, and Cosmetic Act (the 
FD&C Act) (21 U.S.C. 348(f)(1)) provides that, within 30 days after 
publication of an order relating to a food additive regulation, any 
person adversely affected by such order may file objections, 
``specifying with particularity the provisions of the order deemed 
objectionable, stating reasonable grounds therefor, and requesting a 
public hearing upon such objections.''
    Under 21 CFR 171.110 of the food additive regulations, objections 
and requests for a hearing are governed by part 12 (21 CFR part 12) of 
FDA's regulations. Under Sec.  12.22(a), each objection must meet the 
following conditions: (1) Must be submitted on or before the 30th day 
after the date of publication of the final rule; (2) must be separately 
numbered; (3) must specify with particularity the provision of the 
regulation or proposed order objected to; (4) must specifically state 
each objection on which a hearing is requested; failure to request a 
hearing on an objection constitutes a waiver of the right to a hearing 
on that objection; and (5) must include a detailed description and 
analysis of the factual information to be presented in support of the 
objection if a hearing is requested; failure to include a description 
and analysis for an objection constitutes a waiver of the right to a 
hearing on that objection.
    Following publication of the final rule permitting the irradiation 
of fresh lettuce and fresh spinach for control of food-borne pathogens 
and extension of shelf life, we received numerous submissions with 
objections to the rule within the 30-day objection period. The majority 
of these submissions were form letters expressing concern regarding one 
or more of the following issues: (1) Labeling of produce being 
irradiated and (2) potential vitamin depletion resulting from 
irradiation. Many of the form letters also expressed general opposition 
to the final rule, or objected to the rule based on issues that are 
outside the rule's scope such as the regulation and management of the 
meat industry, the number of inspectors currently available to perform 
inspections, and the proximity of cattle farms to produce farms. 
Although most of these letters requested a hearing, no evidence was 
identified in support of any of these objections that could be 
considered in an evidentiary hearing (Sec.  12.22(a)(5)). Therefore, 
these objections do not justify a hearing.\1\ We will not discuss these 
submissions further.
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    \1\ FDA also received letters after the close of the objection 
period that expressed general opposition to the fresh lettuce and 
fresh spinach irradiation rule. Tardy objections fail to satisfy the 
requirements of 21 U.S.C. 348(f)(1) and need not be considered by 
the Agency (see ICMAD v. HEW, 574 F.2d 553, 558 n.8 (D.C. Cir.), 
cert. denied, 439 U.S. 893 (1978)).
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    There were two submissions raising specific objections. One was a 
letter from the Center for Food Safety (CFS) (letter to Docket No. FDA-
1999-F-2405; September 17, 2008) and the second was a letter from Food 
& Water Watch (FWW) (letter to Docket No. FDA-1999-F-2405; September 
22, 2008). The letter from CFS sought revocation of the final rule 
pertaining to two areas, which were enumerated as five specific 
objections. CFS requested a hearing on the issues

[[Page 10354]]

raised by each objection. The letter from FWW agreed with all 
objections raised in the letter from CFS, and requested a hearing and 
stay of effective date for one additional topic not described in the 
CFS letter. A more detailed response to both CFS' and FWW's objections 
is found in section IV. We also received two letters in support of the 
fresh lettuce and fresh spinach rule.

III. Standards for Granting a Hearing

    Specific criteria for deciding whether to grant or deny a request 
for a hearing are set out in Sec.  12.24(b). Under that regulation, a 
hearing will be granted if the material submitted by the requester 
shows, among other things, the following: (1) There is a genuine and 
substantial factual issue for resolution at a hearing; a hearing will 
not be granted on issues of policy or law; (2) the factual issue can be 
resolved by available and specifically identified reliable evidence; a 
hearing will not be granted on the basis of mere allegations or denials 
or general descriptions of positions and contentions; (3) the data and 
information submitted, if established at a hearing, would be adequate 
to justify resolution of the factual issue in the way sought by the 
requester; a hearing will be denied if the data and information 
submitted are insufficient to justify the factual determination urged, 
even if accurate; and (4) resolution of the factual issue in the way 
sought by the person is adequate to justify the action requested; a 
hearing will not be granted on factual issues that are not 
determinative with respect to the action requested (e.g., if the action 
would be the same even if the factual issue were resolved in the way 
sought).
    A party seeking a hearing is required to meet a ``threshold burden 
of tendering evidence suggesting the need for a hearing'' (Costle v. 
Pac. Legal Found., 445 U.S. 198, 214 (1980), reh. denied, 446 U.S. 947 
(1980), citing Weinberger v. Hynson, Westcott & Dunning, Inc., 412 U.S. 
609, 620-21 (1973)). An allegation that a hearing is necessary to 
``sharpen the issues'' or to ``fully develop the facts'' does not meet 
this test (Georgia-Pacific Corp. v. U.S. EPA, 671 F.2d 1235, 1241 (9th 
Cir. 1982)). In judicial proceedings, a court is authorized to issue 
summary judgment without an evidentiary hearing whenever it finds that 
there are no genuine issues of material fact in dispute and a party is 
entitled to judgment as a matter of law (see Fed. R. Civ. P. 56). The 
same principle applies in administrative proceedings (see Sec.  12.24).
    A hearing request must not only contain evidence, but that evidence 
should raise a material issue of fact ``concerning which a meaningful 
hearing might be held'' (Pineapple Growers Ass'n v. FDA, 673 F.2d 1083, 
1085 (9th Cir. 1982)). Where the issues raised in the objection are, 
even if true, legally insufficient to alter the decision, we need not 
grant a hearing (see Dyestuffs and Chemicals, Inc. v. Flemming, 271 
F.2d 281, 286 (8th Cir. 1959), cert. denied, 362 U.S. 911 (1960)). A 
hearing is justified only if the objections are made in good faith and 
if they ``draw in question in a material way the underpinnings of the 
regulation at issue'' (Pactra Industries v. CPSC, 555 F.2d 677, 684 
(9th Cir. 1977)). A hearing need not be held to resolve questions of 
law or policy (see Citizens for Allegan County, Inc. v. FPC, 414 F.2d 
1125, 1128 (D.C. Cir. 1969); Sun Oil Co. v. FPC, 256 F.2d 233, 240-41 
(5th Cir. 1958), cert. denied, 358 U.S. 872 (1958)).
    Even if the objections raise material issues of fact, we need not 
grant a hearing if those same issues were adequately raised and 
considered in an earlier proceeding. Once an issue has been so raised 
and considered, a party is estopped from raising that same issue in a 
later proceeding without new evidence. The various judicial doctrines 
dealing with finality, such as collateral estoppel, can be validly 
applied to the administrative process (see Pac. Seafarers, Inc. v. Pac. 
Far East Line, Inc., 404 F.2d 804, 809 (D.C. Cir. 1968), cert. denied, 
393 U.S. 1093 (1969)). In explaining why these principles ought to 
apply to an Agency proceeding, the U.S. Court of Appeals for the 
District of Columbia Circuit wrote: ``The underlying concept is as 
simple as this: Justice requires that a party have a fair chance to 
present his position. But overall interests of administration do not 
require or generally contemplate that he will be given more than one 
fair opportunity.'' (Retail Clerks Union, Local 1401 v. NLRB, 463 F.2d 
316, 322 (D.C. Cir. 1972).) (See Costle v. Pac. Legal Found., 445 U.S. 
at 215-20. See also Pac. Seafarers, Inc. v. Pac. Far East Line, Inc., 
404 F.2d 804 (D.C. Cir. 1968), cert. denied, 393 U.S. 1093 (1969).)
    In summary, a hearing request must present sufficient credible 
evidence to raise a material issue of fact, and the evidence must be 
adequate to resolve the issue as requested and to justify the action 
requested.

IV. Analysis of Objections and Response to Hearing Requests

    The letter from CFS contains five numbered objections with requests 
for a hearing on each of them, and also appears to have two broad 
objections. FWW's letter agrees with all objections presented by CFS 
and presents one additional objection; they request a hearing and stay 
of effective date on each objection. We address CFS' two broad 
objections first, followed by the specific objections, as well as the 
evidence and information filed in support of each, comparing each 
objection and the information submitted in support of it to the 
standards for granting a hearing in Sec.  12.24(b).

A. CFS' Broad Objections

    Although CFS' letter was formatted as five numbered objections with 
requests for a hearing on each, CFS appears to have two broad 
objections to the final rule providing for the safe use of ionizing 
radiation for control of food-borne pathogens and extension of shelf 
life in fresh lettuce and fresh spinach. In brief, CFS claims that: (1) 
We have improperly relied on studies in other fruits and vegetables and 
(2) we have improperly relied on studies at doses below 4.0 kGy. CFS 
appears to raise these objections to attempt to call into question our 
assessment of the nutritional impact of the final rule and ultimately 
our determination that the irradiation of fresh lettuce and fresh 
spinach up to a maximum dose of 4.0 kGy is safe.
    We disagree that we have improperly relied on studies in other 
fruits and vegetables. We have consistently taken the position that 
various scientifically validated types of data may properly support a 
safety determination for a proposed use of a food additive (see 21 CFR 
170.20(a)). Further, we have consistently taken the position that data 
obtained from specific foods irradiated under specific conditions may 
be extrapolated and generalized to draw conclusions regarding the 
safety of foods of a similar type irradiated under related conditions 
(see 62 FR 64107 at 64110; December 3, 1997, and 70 FR 48057 at 48059; 
August 16, 2005). Other scientific bodies have used this approach as 
well. As explained in our final rule permitting the irradiation of 
molluscan shellfish (70 FR 48057 at 48058), the World Health 
Organization, in its review of the safety data on irradiated food, 
found that safety data on one food type can be extrapolated to other 
foods of similar composition and that individual studies of irradiated 
foods can be integrated into one database (Ref. 1). In the fresh 
lettuce and fresh spinach final rule, we concluded that the body of 
data and information we considered in our review demonstrated the 
safety of fresh lettuce and fresh spinach irradiated up to a maximum 
dose of 4.0 kGy. CFS' suggestion that such information is not

[[Page 10355]]

sufficient to support a safety determination is unsupported by specific 
data or other factual information.
    We also disagree that we improperly relied on studies at doses 
below 4.0 kGy. In analyzing the nutritional adequacy of irradiated 
fresh lettuce and fresh spinach, we evaluated the totality of evidence, 
which included studies of plant-based foods irradiated at a wide range 
of doses (i.e., doses above and below 4.0 kGy), information about the 
susceptibility of vitamins in lettuce and spinach to irradiation, 
information about the susceptibility of vitamins in plant matrices in 
general to irradiation, and estimates of the significance of fresh 
lettuce and fresh spinach as sources of these vitamins. For the 
assessment of the significance of fresh lettuce and fresh spinach as 
sources of vitamins, we considered the levels of the vitamins present 
in food, published information about the relative contribution of fresh 
lettuce and fresh spinach to the total dietary intake of these 
vitamins, and published studies and reviews summarizing the limited 
bioavailability of certain vitamins from green leafy vegetables. 
Importantly, we noted that folate, provitamin A carotenoids, and 
vitamin K all have limited bioavailability from green leafy vegetables; 
hence the contribution of these foods to overall intake of these 
vitamins is diminished, despite the presence of the vitamins in high 
amounts in foods such as spinach (Ref. 2).\2\ For example, in 2001 the 
Institute of Medicine (IOM) concluded that provitamin A bioavailability 
from dietary sources (i.e., not supplemental forms) is half that 
previously thought (Ref. 3), and that very low bioavailability (<10 
percent) is associated with raw green leafy vegetables (Ref. 4). 
Similar findings of limited bioavailability have been reported for 
folate and vitamin K from green leafy vegetables, particularly relative 
to supplements and other food sources, as discussed in our nutrition 
memorandum (Ref. 2).
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    \2\ Only vitamin K is present in high amounts in iceberg 
lettuce.
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    We considered studies performed at doses ranging from 0.5 kGy to 56 
kGy to ascertain the relative amount of vitamin loss at those doses. 
Specifically, we assessed studies performed at doses above 4.0 kGy for 
folate, provitamin A carotenoids, vitamin K, and vitamin C. As such, we 
did not rely solely on studies conducted below 4.0 kGy to perform the 
nutritional assessment; rather we considered all available data 
pertaining to potential nutrient loss for those vitamins. The available 
data included information on the levels of vitamins following treatment 
with doses below 4.0 kGy, information on the levels of vitamins 
following treatment with doses above 4.0 kGy, information on the 
limited bioavailability of certain vitamins and provitamins from green 
leafy vegetables, and information pertaining to the relative 
contribution of these sources to the total dietary intake of individual 
vitamins. Our assessment of the available data does not provide reason 
for a safety concern regarding potential vitamin loss from irradiating 
fresh lettuce and fresh spinach up to a maximum dose of 4.0 kGy. CFS 
provided no information to support its assertions that our reliance on 
studies in other fruits and vegetables and studies performed at doses 
below 4.0 kGy would call into question our assessment of the 
nutritional impact of the final rule and ultimately our determination 
that irradiated fresh lettuce and fresh spinach at 4.0 kGy is safe. A 
hearing will not be granted on the basis of mere allegations or denials 
or general descriptions of positions and contentions (Sec.  
12.24(b)(2)). Therefore, we are denying CFS' objection and request for 
a hearing based on this objection.

B. First Numbered Objection: CFS' Contention That FDA Failed To 
Determine the Magnitude of Nutrient Losses at or Near the Maximum 
Permitted Dose of 4.0 kGy

    The first objection raised by CFS contends that FDA ``fails to 
determine the magnitude of nutrient losses to be expected from 
irradiation of fresh spinach or iceberg lettuce at or near the upper 
limit approved in the rule: 4 kGy.'' They expound upon this objection 
by asserting that the majority of the studies cited in our nutrition 
memorandum (Ref. 2) were performed at doses below 2 kGy and on fruits 
and vegetables other than fresh spinach and fresh lettuce. The 
objection includes CFS' assertions regarding the following 
``nutrients'': Carotenoids/vitamin A,\3\ folate, vitamin K, and vitamin 
C. CFS' discussion for each nutrient contains additional objections.
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    \3\ We note that while CFS refers to these components as 
nutrients, not all carotenoids are vitamin A precursors and not all 
carotenoids have been shown to be essential to the human diet.
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    CFS further contends that we failed to determine the magnitude of 
nutrient losses to be expected from irradiating fresh spinach and fresh 
lettuce at or near the petitioned maximum dose because we did not 
address the synergistic effects of irradiation and heating. According 
to CFS, we should have considered that ``irradiation-induced nutrient 
losses will be superadded to those from other industrial or home food 
processing methods.'' CFS' assertion that we failed to determine the 
magnitude of nutrient losses at or near the petitioned maximum dose 
ultimately attempts to call into question our determination that the 
irradiation of fresh lettuce and fresh spinach up to a maximum dose of 
4.0 kGy is safe.
    Contrary to CFS' contention and, as demonstrated in our nutrition 
memorandum (Ref. 2), we evaluated both the extent of nutrient loss and 
the nutritional importance of any such losses resulting from 
irradiation of fresh lettuce and fresh spinach at doses up to 4.0 kGy. 
Our review of a large body of data relevant to the nutritional adequacy 
and wholesomeness of irradiated foods has demonstrated that irradiation 
does not significantly alter the macronutrients (i.e., proteins, fats, 
and carbohydrates) of the food at the petitioned doses. However, it has 
been shown that some vitamins are susceptible to irradiation. The 
susceptibility of a vitamin to irradiation depends on factors such as 
the chemical structure of the vitamin, the conditions of processing, 
the conditions and duration of storage, and the composition of food. To 
determine whether or not partial vitamin loss is significant, it is 
essential to consider the relative contribution of the vitamin from the 
irradiated food to the total dietary intake of the vitamin and the 
sensitivity of that vitamin to irradiation.
    Therefore, our analysis focused primarily on vitamins that are 
present in relatively high amounts in fresh lettuce and/or fresh 
spinach, which were identified using the criteria for nutrient content 
claims (Sec.  101.54 (21 CFR 101.54)),\4\ and that contribute more than 
a trivial amount to the total dietary intake of that vitamin (i.e., 
more than 1 to 2 percent). The nutrients which meet both criteria are: 
Vitamin A, vitamin K, and folate. Therefore, our discussion of the 
nutritional impact of the proposed conditions of irradiation on fresh 
lettuce and fresh spinach focused on these three nutrients.\5\ For each 
of these

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nutrients, we evaluated the dietary requirements, dietary sources, and 
susceptibility of vitamins to irradiation, and we found that there 
would be no significant impact on the dietary intake of those 
nutrients.
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    \4\ In accordance with Sec.  101.54(b), foods containing >= 20 
percent of the Reference Daily Intake or Daily Reference Value per 
reference amount customarily consumed, the amount of food 
customarily consumed per eating occasion such as in one meal or 
snack, may be labeled as ``excellent source of,'' ``high in,'' or 
``rich in'' a given nutrient.
    \5\ Spinach contains high levels of vitamin C, but the combined 
group of spinach and ``greens'' (e.g., kale, chard, chives) 
contributes less than 2 percent to the total dietary intake of 
vitamin C in the United States (Ref. 5); hence, vitamin C was not an 
area of focus in the final rule, although it was addressed in the 
our nutrition memorandum.
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1. Provitamin A Carotenoids/Vitamin A
    In the analysis specific to irradiation-induced loss of provitamin 
A, CFS objects to the use of six studies, five of which did not involve 
the irradiation of fresh lettuce or fresh spinach. We have reviewed a 
large body of data relevant to the safety of irradiated foods.\6\ When 
evaluating the safety of a source of radiation to treat food intended 
for human consumption, we address three general areas: (1) Potential 
toxicity, (2) nutritional adequacy, and (3) effects on the 
microbiological profile of the treated food. We have consistently taken 
the position that various scientifically validated types of data may 
properly support a safety determination for a proposed use of a food 
additive. For example, in the case of food irradiation, we have taken 
advantage of the extensive research and large body of knowledge 
concerning the principles of radiation chemistry and the chemical 
composition of foods. CFS' suggestion that data and information derived 
from studies of analogous irradiated foods are not sufficient to 
support a determination that irradiated fresh lettuce and fresh spinach 
is safe is unsupported by specific data or other factual information.
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    \6\ During the early 1980s, a joint Food and Agriculture 
Organization/International Atomic Energy Agency, World Health 
Organization (FAO/IAEA/WHO) Expert Committee evaluated the 
toxicological and microbiological safety and nutritional adequacy of 
irradiated foods. The Expert Committee concluded that irradiation of 
any food commodity at an average dose of up to 10 kGy presents no 
toxicological hazard (Ref. 6). In the 1990s, WHO reanalyzed the 
safety data on irradiated foods, including additional studies (see 
51 FR 13376 at 13378, April 18, 1986) and concluded that the 
integrated toxicological database is sufficiently sensitive to 
evaluate safety and that no adverse toxicological effects due to 
irradiation were observed in the dose ranges tested (Ref. 1). 
Furthermore, our Bureau of Foods Irradiated Foods Committee assessed 
hundreds of toxicology studies in our files and determined that 
studies involving irradiated foods did not demonstrate adverse 
effects (Ref. 7). These studies, taken as a whole, serve as an 
independent method to assess toxicological safety. The studies 
considered in that evaluation include those that have been relied on 
by FDA in previous evaluations of the safety of irradiated foods, 
including lettuce, spinach, molluscan shellfish, shell eggs, meat, 
and poultry (see 73 FR 49593, August 22, 2008; 70 FR 48057, August 
16, 2005; 65 FR 45280, July 21, 2000; 62 FR 64107, December 3, 1997; 
55 FR 18538, May 2, 1990; and 51 FR 13376), along with additional 
data and information from our files and from other information 
available to us, including published reports regarding studies in 
which animals were fed a wide variety of foods irradiated at 
different doses.
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    Furthermore, vitamin A exists in food sources in two different 
forms: (1) Preformed vitamin A (retinol) and (2) provitamin A 
(carotenoids).\7\ Preformed vitamin A is found in some animal-derived 
foods (e.g., organ meats, dairy products, eggs) and in fortified foods 
such as ready-to-eat cereals, whereas provitamin A carotenoids are 
found in foods such as dark-green vegetables, orange vegetables, orange 
fruits, and red palm oil (Ref. 3). There is a diverse set of foods that 
contributes to the total dietary intake of vitamin A in a balanced 
diet, including vitamin A-rich foods and provitamin A carotenoid-rich 
foods. Among the wide range of plant-based foods containing provitamin 
A carotenoids, fresh lettuce and fresh spinach are among the poorer 
dietary sources, due to limited bioavailability of carotenoids from 
these foods, as discussed earlier and reviewed by the IOM (Ref. 4). 
Hence, even for fresh spinach, which has a relatively high 
concentration of provitamin A, the actual contribution of this food to 
total vitamin A intake is minor due to limited bioavailability (Ref. 
2). Therefore, considering the insensitivity of vitamin A and 
provitamin A carotenoids found in spinach to irradiation and the 
limited contribution of these particular foods to the total dietary 
intake of vitamin A, the small losses of vitamin A that might result 
from the irradiation of fresh lettuce or fresh spinach are not 
nutritionally significant (Ref. 2).
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    \7\ There are also two types of carotenoids: Provitamin A 
carotenoids that are vitamin A precursors, meaning that they 
contribute to vitamin A activity, and nonprovitamin A carotenoids 
that are not vitamin A precursors and, therefore, do not contribute 
to vitamin A activity.
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    Additionally, CFS asserts that there is ``no discussion of the 
apparent discrepancy between no carotenoid loss in carrots at 2 kGy and 
`low to moderate losses in beta and alpha-carotene' * * * in carrots 
irradiated at less than half that dose, 0.8 kGy.'' \8\ We were aware of 
the discrepancies between the two studies during our review. However, 
we concluded that differences in observed losses between the studies 
did not call into question our assessment of the nutritional impact of 
the final rule and determination that irradiating fresh lettuce and 
fresh spinach up to a maximum dose of 4.0 kGy is safe. The two studies 
differed in treatment dose but also other factors, including storage 
time, temperature during irradiation and storage, and analysis of total 
carotenoids (Ref. 8) versus individual carotenoids (Ref. 9), which 
could impact the reported levels of carotenoids. Despite differences in 
study design, losses of total carotenoids (alpha-carotene plus beta-
carotene) were less than 20 percent in both studies. Losses of alpha-
carotene (28 percent) were reported to be slightly higher than losses 
of beta-carotene (8 percent) in the Baraldi et al. paper (Ref. 9); 
however, it is important to note that alpha-carotene is present in 
lower amounts than beta-carotene in carrots and has half the retinol 
activity equivalence of beta-carotene (discussed further in this 
document). Further, alpha-carotene is not present in meaningful amounts 
in either spinach or iceberg lettuce; hence; this provitamin was not 
highlighted in the nutrition memorandum.
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    \8\ The studies to which CFS refers are the Hajare et al. study 
(Ref. 8) that looked at the loss in total carotenoids in carrots 
irradiated at 2.0 kGy and the Baraldi et al. study that was reviewed 
by Diehl (Ref. 9) and was conducted at 0.8 kGy showing low to 
moderate losses in beta- and alpha-carotene. Our nutrition 
memorandum (Ref. 2) notes that the study conducted at 0.8 kGy 
showing low to moderate losses in beta- and alpha-carotene was 
reviewed within the Diehl reference.
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    The nutritional significance of provitamin A carotenoids is that 
provitamin A carotenoids, including alpha and beta-carotenes, are 
precursors of vitamin A. Even at the highest observed losses in the 
cited studies (28 percent for alpha-carotene), one would not expect 
substantive losses of vitamin A in the total diet, in part due to 
inefficient conversion of alpha-carotene to retinol and the limited 
bioavailability of alpha-carotene from plant sources. In recognition of 
these limitations, the IOM has established a retinol activity 
equivalence of 24 micrograms of alpha-carotene (from food) to 1 
microgram of retinol (meaning 24 micrograms of alpha-carotene in 
carrots yield only 1 microgram of retinol in the body). In contrast, 
the IOM estimates that 12 micrograms of food-borne beta-carotene yield 
one microgram of retinol in the body. Despite the relatively high 
concentration of beta-carotene in spinach, the bioavailability of beta-
carotene from green leafy vegetables is generally considered to be low 
relative to other food sources of beta-carotene (even lower than raw 
carrot) due to inhibitory effects of the food matrix (i.e., the 
components of the food) on carotenoid release from food. Release of the 
carotenoids from the food matrix is a step that precedes the 
incorporation of carotenoids into mixed lipid micelles and their 
subsequent absorption (Refs. 4 and 10). This topic has been addressed 
in section IV.A and in an extensive review by the IOM (Ref. 3). 
Considering the limited bioavailability of provitamin A carotenoids 
from fresh lettuce and fresh spinach, the limited contribution

[[Page 10357]]

of these foods to the total dietary intake of vitamin A, and the 
relative radiation resistance of plant-based carotenoids, we determined 
that the loss of carotenoids would not be a safety concern. We also 
note that although provitamin A carotenoids are susceptible to partial 
losses due to irradiation, these losses are somewhat variable and can 
be minimized by control of various irradiation conditions (e.g., 
temperature, packaging, headspace gas). Therefore, while there were 
variable (but not extensive) losses observed in the two carrot studies, 
this apparent discrepancy does not call into question the outcome of 
this final rule. CFS' objection attempts to call into question our 
assessment of the nutritional impact of the final rule and implies that 
there is a safety issue due to a discrepancy in losses between the two 
cited studies; however, they do not provide any information or data to 
support their objection. We are therefore denying CFS' objection and 
request for a hearing because a hearing will not be granted on the 
basis of mere allegations or denials or general descriptions of 
positions and contentions (Sec.  12.24(b)(2)).
    Further, CFS asserts that we failed to determine the magnitude of 
nutrient losses from irradiating fresh lettuce and fresh spinach 
because the discussion of carotenoids was limited to total carotenoid 
levels as opposed to analyzing specific carotenoids with ``particular 
nutritional relevance,'' such as lutein and zeaxanthin. To support this 
objection, CFS cites a study performed by Semba and Dagnelie (Ref. 11), 
that, according to CFS, demonstrates the nutritional relevance of 
lutein and zeaxanthin because ``[l]ow dietary intake and plasma levels 
of lutein and zeaxanthin have been associated with low macular pigment 
density and increased risk of age-related macular degeneration, and on 
this basis these carotenoids have been considered good candidates for 
designation as a [sic] `conditionally essential' nutrients.'' CFS fails 
to note that the same journal article states that these carotenoids 
``may play a role in the pathogenesis of age-related macular 
degeneration,'' that ``studies are beginning to suggest that they fit 
the criteria for conditionally essential nutrients'' and that 
``[s]hould controlled clinical trials show lutein and/or zeaxanthin 
supplementation protects against the developments or progression of 
ARMD [age-related macular degeneration] and other eye diseases, then 
lutein and zeaxanthin could be considered as conditionally essential 
nutrients for humans'' (emphasis added) (Ref. 11). Thus, none of these 
statements supports CFS' claim that there currently is a scientific 
basis which would provide a substantial rationale for us to perform 
analysis on individual carotenoids. Furthermore, it should be noted 
that both lutein and zeaxanthin are nonprovitamin A carotenoids, 
meaning that neither contributes to vitamin A activity.
    Additionally, in the most recently published report from the IOM on 
Dietary Reference Intakes (DRIs), which updated recommendations for the 
intake of vitamin C, vitamin E, selenium, and discussed carotenoids, 
the IOM stated: ``[a] large body of observational epidemiological 
evidence suggests that higher blood concentrations of [beta]-carotene 
and other carotenoids obtained from foods are associated with lower 
risk of several chronic diseases. This evidence, although consistent, 
cannot be used to establish a requirement for [beta]-carotene or 
carotenoid intake because the observed effects may be due to other 
substances found in carotenoid-rich food, or to other behavioral 
correlates of increased fruit and vegetable consumption * * * 
[a]lthough no DRIs are proposed for [beta]-carotene or other 
carotenoids at the present time, existing recommendations for increased 
consumption of carotenoid-rich fruits and vegetables are supported . . 
.'' (Ref. 4).
    After reviewing the relevant scientific studies, the IOM did not 
establish a requirement for carotenoid intake; therefore, unless the 
carotenoids contributed to vitamin A levels in the diet, we did not 
analyze specific carotenoids. For these reasons, there was no evidence 
that individual carotenoids needed to be analyzed when we made our 
safety decision on irradiation of fresh lettuce and fresh spinach at 
the petitioned doses. Accordingly, we are denying CFS' objection and 
request for a hearing because the data and information submitted by CFS 
are insufficient to justify the factual determination urged, even if 
accurate (Sec.  12.24(b)(3)).
2. Folate
    CFS offers three arguments to support their view that we 
erroneously concluded that irradiation-induced folate loss in fresh 
lettuce and fresh spinach is not nutritionally significant. First, CFS 
asserts that we did not consider any studies of irradiation-induced 
folate losses in iceberg lettuce. Second, CFS asserts that only one of 
the cited studies pertained specifically to fresh spinach. Third, CFS 
contends that we failed to discuss certain results from the study 
performed by M[uuml]ller and Diehl (Ref. 12).
    First, CFS asserts that ``though iceberg lettuce contains 
considerably less folate than spinach * * *, lettuces as a group supply 
a larger percentage of folate than the spinach/greens groups to the 
average American diet,'' and therefore we should have considered 
studies of irradiation-induced folate losses in iceberg lettuce. 
However, we note that iceberg lettuce is just one leafy vegetable 
within the category of ``lettuces'' (which includes Romaine, 
butterhead, green leaf, etc.); among the lettuces, iceberg lettuce 
contains the lowest concentration of folate. In our nutrition 
memorandum (Ref. 2), we explain that iceberg lettuce is not considered 
to be a ``good source'' of folate in accordance with Sec.  101.54(c) 
and that enriched and fortified foods (e.g., cereal grains and grain-
based products) make the greatest contribution to folate in the diet. 
Furthermore, the form of folate used for fortification is more 
bioavailable than naturally occurring food folates. While we did not 
provide an analysis for iceberg lettuce, we did analyze the potential 
folate loss in spinach, which is considered to contain relatively large 
amounts of folate. We concluded that irradiation of spinach at doses up 
to 4.0 kGy would not have a significant impact on the dietary intake of 
folate in the U.S. diet. It follows that iceberg lettuce, which does 
not meet the criteria for a ``good source'' of this nutrient, would not 
have a significant impact on the dietary intake of folate either. 
Therefore, the information provided by CFS that lettuces ``as a group'' 
supply a larger percentage of folate than the spinach/greens group is 
not sufficient to demonstrate that we should have considered 
irradiation-induced losses in iceberg lettuce. Accordingly, we are 
denying CFS' objection and request for a hearing because the data and 
information submitted by CFS are insufficient to justify the factual 
determination urged, even if accurate (Sec.  12.24(b)(3)).
    Second, CFS asserts that only one study was presented that 
considered irradiation-induced folate loss in fresh spinach. While we 
cited two studies considering folate loss, CFS asserts that only one 
study is relevant because it was performed in fresh spinach. In the 
final rule, we explained our position that many scientifically valid 
types of data may properly support a finding that a proposed use of a 
food additive is safe. CFS has not provided any evidence that our 
consideration of studies considering folate loss is inadequate to 
determine the magnitude of nutrient losses from irradiating fresh 
lettuce and fresh

[[Page 10358]]

spinach at the petitioned doses. CFS has also not provided any 
additional studies that we should have considered in assessing folate 
loss. We are therefore denying CFS' objection and request for a hearing 
because a hearing will not be granted on the basis of mere allegations 
or denials or general descriptions of positions and contentions (Sec.  
12.24(b)(2)).
    Third, CFS contends that our discussion of the study performed by 
M[uuml]ller and Diehl (Ref. 12) did not include certain results. CFS 
asserts that the study reported a 12 percent loss of folate in fresh 
spinach when irradiated at 2.5 kGy, but we did not discuss the 21 
percent loss of folate in fresh spinach when irradiated at 5.0 kGy or 
the 13 percent loss of folate when dehydrated spinach was irradiated at 
10 kGy. The M[uuml]ller and Diehl study was included in the petition 
and was analyzed by FDA when we made our safety assessment. We 
acknowledge that a greater loss of folate was shown when fresh spinach 
was irradiated at a higher dose (i.e., 5.0 kGy) when compared to the 
lower dose of 2.5 kGy. The nutrition memorandum cited the 2.5 kGy 
result, since it was within the range of doses under consideration in 
the petition and highlighted the general stability of food folate. The 
5.0 kGy dose, although greater than the dose under consideration in the 
petition, still shows that nearly 80 percent of folate is maintained, 
thus supporting the general stability of this vitamin to moderate doses 
of irradiation. In our review of the petition, we considered the health 
implications from folate loss in spinach at the maximum petitioned dose 
(4.0 kGy), and concluded that such folate loss is not nutritionally 
significant because: (1) Fresh lettuce and fresh spinach contribute 
minimally to the dietary intake of folate; and (2) folate is found to 
be consistently stable to irradiation under various conditions that 
have been detailed in published studies.
    Therefore, the information provided by CFS that a greater loss of 
folate was shown when fresh spinach was irradiated at a higher dose 
does not call into question our assessment of the nutritional impact of 
the final rule and determination that irradiating fresh lettuce and 
fresh spinach up to a maximum dose of 4.0 kGy is safe. Accordingly, we 
are denying CFS' objection and request for a hearing because the data 
and information submitted by CFS are insufficient to justify the 
factual determination urged, even if accurate (Sec.  12.24(b)(3)).
3. Vitamin K
    CFS objects to the final rule based on our nutrition memorandum for 
vitamin K because CFS asserts that: (1) The Knapp and Tappel study 
(Ref. 13) cited in the nutrition memorandum involved the irradiation of 
pure vitamin K in an isooctane solution and not in a food matrix; (2) 
the Richardson et al. study (Ref. 14) cited in the nutrition memorandum 
involved indirect measurement of vitamin K activity in spinach and 
other vegetables after freezing, irradiation at 28 or 56 kGy, or heat-
processing; (3) we ``failed to consider'' conflicting results in two 
studies (Richardson et al. (Ref. 15) and Metta et al. (Ref. 16)) from 
the same period as the Richardson et al. study (Ref. 14) cited in the 
nutrition memorandum; and (4) we failed to consider the 2007 study by 
Hirayama et al. (Ref. 17) that raises ``similar questions'' regarding 
the nutritional impact of irradiating fresh lettuce and fresh spinach.
    First, CFS contends that the Knapp and Tappel study that involved 
the irradiation of pure vitamin K in an isooctane solution rather than 
a food matrix is of ``limited value for assessing irradiation-induced 
loss of Vitamin K in irradiated spinach or iceberg lettuce.'' We 
disagree with CFS' assessment. To the contrary, we maintain that this 
study establishes vitamin K as one of the least sensitive fat-soluble 
vitamins to irradiation, and therefore is relevant for assessing 
irradiation-induced losses. Even though the study was performed in an 
isooctane solution, the relative sensitivities of the vitamins to 
irradiation do not change; rather, the food matrix can offer protection 
to the vitamin, lessening the effects of irradiation because the 
radiation effects will be distributed to all components of the food, 
i.e., the principle of mutual protection (Ref. 18). We reviewed this 
study and found it to be adequate to determine comparative 
radiosensitivities under uniform conditions for vitamins A, D, E, K, as 
well as carotene. Therefore, the information provided by CFS that the 
Knapp and Tappel study involved the irradiation of vitamin K in an 
isooctane solution rather than a food matrix does not call into 
question the value of the Knapp and Tappel study in helping us assess 
the nutritional impact of the final rule. We are denying CFS' objection 
and request for a hearing because the data and information submitted by 
CFS are insufficient to justify the factual determination urged, even 
if accurate (Sec.  12.24(b)(3)).
    Second, CFS contends that the Richardson et al. study (Ref. 14) is 
of limited value because the study ``estimated'' the vitamin K content 
through indirect measurement of the prothrombin times of chick plasma, 
and the study reported ``anomalous results.'' According to CFS, the 
authors of the study reported an increase in vitamin K activity in 
irradiated spinach over time in addition to variability in the values 
obtained from different assays. CFS cites these findings to support its 
contention that we erroneously determined the magnitude of vitamin K 
loss from irradiation of fresh lettuce and fresh spinach under the 
petitioned conditions.
    We disagree that the indirect measurement of vitamin K activity in 
spinach precludes this study from being useful in the assessment of 
potential nutrient losses. In our review of this study, we considered 
the prothrombin time measurement in the chick bioassay, even though 
indirect, to be relevant for assessing vitamin K activity in foods 
since the chick is sensitive to dietary vitamin K deprivation. 
Moreover, the prothrombin time measurement is a common parameter for 
measuring vitamin K status for clinical purposes (Refs. 3 and 19). 
Furthermore, we acknowledge the variability in the data cited by CFS; 
however, CFS' objection fails to note that the authors of the study in 
question concluded that ``regardless of the variability in results * * 
* there was no appreciable loss of vitamin K activity in the foods 
preserved by any process or when stored for 15 months'' (Ref. 14). 
Variability in results is not grounds for a study to be ignored; 
important information about general trends may still be gleaned from 
this study, which consistently found vitamin K activity was not reduced 
by irradiation relative to frozen or heat-processed controls. As part 
of their objection, CFS specifically notes that vitamin K activity 
after 15 months of storage was higher than directly after irradiation 
at both irradiation doses; however, it should be noted that irradiation 
may either accelerate or decelerate metabolic changes within the food, 
a factor which may account for differences observed following storage 
(Ref. 9). For example, it is known that vitamin K resides in the 
chloroplasts and has tight association with the thylakoid membranes. 
This tight association may account for the limited bioavailability of 
vitamin K from green leafy vegetables (Ref. 20). Processing techniques 
such as irradiation (particularly at high doses) may result in 
disruption of thylakoid membranes, an

[[Page 10359]]

effect which may become more evident after long term storage and may 
account at least in part for variability in observed vitamin K activity 
after storage. As such, the information provided by CFS that the 
Richardson et al. study involved indirect measurement of vitamin K 
activity does not call into question the value of the Richardson et al. 
study in helping us assess the nutritional impact of the final rule. We 
are therefore denying CFS' objection and request for a hearing because 
the data and information submitted by CFS are insufficient to justify 
the factual determination urged, even if accurate (Sec.  12.24(b)(3)).
    Third, CFS contends that we failed to consider conflicting results 
from two studies cited by CFS: A study performed by Richardson et al. 
(Ref. 15); and a study performed by Metta et al. (Ref. 16). Although 
neither of these studies was cited in our nutrition memorandum, we were 
aware of both studies when evaluating the nutritional impact of 
irradiating fresh lettuce and fresh spinach up to a maximum dose of 4.0 
kGy. We disagree with CFS' conclusions that the Richardson et al. study 
demonstrated that the ``Vitamin K activity of diets containing small 
quantities of Vitamin K was markedly decreased by irradiation with 
sterilizing doses of gamma rays.'' CFS' objection fails to note that, 
in the experimental report, the authors concluded that ``practically 
none of the vitamin K activity was lost by the irradiation process when 
vitamin K1 was the source of the vitamin in the diet.'' The 
article also concluded that ``[s]ince the incidence of hemorrhage was 
higher in the chicks receiving the untreated spinach than it was in 
those receiving the irradiated spinach, it was concluded that no 
destruction of vitamin K occurred by the irradiation process.''
    In addition, the Metta et al. study (Ref. 16) reported vitamin K 
deficiency in rats induced by the feeding of irradiated beef. However, 
we deemed the study irrelevant to the assessment of vitamin K loss in 
fresh lettuce and fresh spinach because the Metta et al. study assessed 
the vitamin K destruction of the more labile form of vitamin K found in 
meat (menaquinone). There are a number of different forms of vitamin K, 
including, but not limited to: Phylloquinone (vitamin K1)--
the only important molecular form found in plants, menaquinones 
(vitamin K2)--which refers to a series of compounds produced 
by gut bacteria but also to a form of vitamin K2, termed 
``menaquinone-4'' that is produced in animal tissues from conversion of 
dietary vitamin K (K1, K3), and menadione 
(vitamin K3), a synthetic form (Refs. 3, 21, and 22).
    Phylloquinone is the form of vitamin K that is found in spinach and 
other leafy greens, whereas menaquinone, although present in minor 
amounts, is the dominant form found in beef along with lesser amounts 
of dietary phylloquinone. The radiosensitivities differ among various 
forms of vitamin K. For example, Richardson et al. reported menadione 
(vitamin K3) is more readily destroyed by ionizing radiation 
than either phylloquinone (vitamin K1) or vitamin 
K5 (a vitamin K analog) (Ref. 15). The Metta et al. study 
assessed the destruction of vitamin K found in meat and the effect on 
rats fed a limited diet; the lability of vitamin K in beef \9\ has been 
noted in numerous published reviews, including those of WHO (Ref. 23), 
Thayer et al. (Ref. 24); and Diehl et al. (Ref. 9). We determined that 
the Metta et al. study was not relevant to the assessment of potential 
irradiated-induced phylloquinone losses in fresh lettuce and fresh 
spinach, and did not highlight this reference in our nutrition 
memorandum.
---------------------------------------------------------------------------

    \9\ We note that although Metta et al. does not identify the 
form of vitamin K in beef tissue, other studies have reported 
menaquinone-4 as the predominant form of vitamin K in beef tissue.
---------------------------------------------------------------------------

    We do not agree with CFS' contention that our nutritional 
assessment of irradiated fresh lettuce and fresh spinach is called into 
question by these studies. Neither of these studies includes any 
information or data that would call into question our findings 
regarding the nutritional impact of irradiation under the petitioned 
conditions. We are therefore denying CFS' objection and request for a 
hearing because the data and information submitted by CFS are 
insufficient to justify the factual determination urged, even if 
accurate (Sec.  12.24(b)(3)).
    Lastly, CFS asserts that a study conducted by Hirayama et al. (Ref. 
17) was not reviewed by FDA in the approval process to permit ionizing 
radiation to treat fresh lettuce and fresh spinach, and therefore calls 
into question our nutritional assessment and ultimately our safety 
conclusion. In the Hirayama et al. study, germ-free mice were fed 
pelleted, sterilized animal feed. According to CFS, vitamin 
K3, a synthetic form of vitamin K, was eliminated when the 
pure compound was added to the feed and irradiated at 50 kGy. CFS notes 
that the study also showed that vitamin K1, the form found 
in spinach, was reduced by approximately 68 percent after the pelleted 
feed was exposed to irradiation doses of 50 kGy. CFS objects to the 
final rule, asserting that this study demonstrates the need for more 
research to determine the ``differential sensitivities'' of the two 
forms of vitamin K. We do not agree that our nutritional assessment and 
the safety of irradiated fresh lettuce or fresh spinach up to a maximum 
dose of 4.0 kGy are called into question by this study.
    As previously mentioned in this document, research has demonstrated 
that different forms of vitamin K have variable sensitivities to 
irradiation. For example, the Richardson et al. study (Ref. 15) cited 
by CFS investigated the effects of ionizing radiation on vitamin K when 
different sources were used (i.e., probing the ``differential 
sensitivities''). The sources of this vitamin were K1, 
K3, K5, dehydrated alfalfa leaf meal, and fresh 
spinach. The authors concluded that menadione (K3) was more 
readily destroyed by irradiation than either vitamin K1 or 
K5, and practically no destruction of vitamin K 
(phylloquinone) occurred when the dietary source was natural (i.e., 
from alfalfa leaf meal and spinach). Clearly, it is understood that 
different forms of vitamin K can have variable sensitivity to 
irradiation, and we were aware of this fact when evaluating the 
nutritional adequacy of irradiated lettuce and spinach (Ref. 25). In 
addition, the petition proposes to irradiate spinach in its natural 
form, and the Richardson et al. study, which provides the most 
pertinent results (Ref. 15), demonstrated that there was practically no 
destruction of vitamin K from this natural source. Furthermore, the WHO 
report we evaluated during review of the petition contained information 
regarding the varied properties of these different forms of vitamin K 
(Ref. 20). Therefore, the Hirayama et al. study raised by CFS does not 
call into question our assessment of the nutritional impact of the 
final rule; we continue to conclude from all of the available evidence 
that the irradiation of fresh lettuce and fresh spinach up to a maximum 
dose of 4.0 kGy will have no significant impact on the total dietary 
intake of vitamin K and is safe. We are denying CFS' objection and 
request for a hearing because the data and information submitted by CFS 
are insufficient to justify the factual determination urged, even if 
accurate (Sec.  12.24(b)(3)).
4. Vitamin C
    CFS asserts that the final rule does not provide an assessment of 
vitamin C loss from irradiation and further alleges that our assessment 
of irradiation-induced vitamin C loss in our nutrition memorandum is 
erroneous. CFS argues

[[Page 10360]]

that the studies we reviewed regarding irradiation-induced loss of 
vitamin C showed varied results and that one source of variation in 
that loss is whether ascorbic acid (AA) was measured or whether AA plus 
dehydroascorbic acid (DHAA) was measured. Measuring AA plus DHAA yields 
the total ascorbic acid (TAA). Specifically, CFS states that, in light 
of the divergent data, experiments for irradiation of fresh lettuce and 
fresh spinach should be conducted measuring TAA. CFS also contends that 
a source of variation in vitamin C can arise from ``differential 
Vitamin C loss in different fruits and vegetables.''
    We evaluated the vitamin C loss in irradiated fresh lettuce and 
fresh spinach and the evaluation was provided in our nutrition 
memorandum (Ref. 2). However, because fresh lettuce and fresh spinach 
are not major contributors to vitamin C in the U.S. diet, the question 
of vitamin C loss from these foods was not discussed in the final rule. 
While spinach has a relatively high concentration of vitamin C, the 
combined food group of ``spinach/greens'' contributes less than 2 
percent to the total intake of vitamin C in the diet. Other major food 
sources (e.g., citrus fruit, fortified juice drinks, tomatoes, peppers, 
potatoes, broccoli) provide the majority of vitamin C in the U.S. diet. 
We therefore determined that little if any reduction in intake of 
vitamin C in the U.S. diet is expected to result from irradiation of 
fresh lettuce and fresh spinach under the petitioned conditions of use.
    We agree that the studies cited in our nutrition memorandum appear 
to report divergent results; however, for all these studies, we 
provided an explanation for each set of differences. For example, our 
nutrition memorandum states that, ``[m]any of the early studies of the 
effects of irradiation on vitamin C levels measured AA levels only and 
consequently reported artificially high decreases in vitamin C,'' and 
``AA losses of irradiated foods relative to controls may be quite 
different depending on whether AA levels are recorded immediately after 
irradiation or after typical storage conditions.'' The memorandum also 
states that, ``[i]n the most recent studies conducted on spinach and 
iceberg lettuce, when irradiation has been conducted at doses 
reflective of those that would be practical for maintaining acceptable 
sensory properties, reported losses were minimal.'' Thus, the 
information provided by CFS, that the studies we reviewed regarding 
irradiation-induced loss of vitamin C showed varied results, does not 
call into question our assessment of the nutritional impact of the 
final rule or our conclusion that irradiating fresh lettuce and fresh 
spinach up to a maximum dose of 4.0 kGy is safe. We evaluated the 
totality of evidence and determined that the irradiation of fresh 
lettuce and fresh spinach up to a maximum dose of 4.0 kGy was safe. We 
are denying CFS' objection and request for a hearing because the data 
and information submitted by CFS are insufficient to justify the 
factual determination urged, even if accurate (Sec.  12.24(b)(3)).
5. Synergistic Effects of Irradiation and Heating
    CFS contends that we do not address the synergistic effects of 
irradiation and heating, stating that nutrient losses would be even 
greater for dual processing compared to irradiation alone. In support 
of this objection, CFS cites a table in ``Safety of Irradiated Foods'' 
by Diehl (Ref. 9) specifically showing synergistic losses of vitamin E. 
We are aware that synergistic losses have been noted for vitamin E and 
thiamin, two vitamins that are particularly sensitive to irradiation; 
however, synergistic effects have not been observed for all vitamins or 
in all food types (Ref. 24). To determine the potential impact of 
irradiation at levels up to 4.0 kGy on the nutritional value of fresh 
lettuce and fresh spinach, we considered all vitamins known to be 
present in these foods, and primarily focused on vitamins that are 
present in relatively high amounts in one or both of these foods and 
vitamins for which lettuce and spinach contribute more than a trivial 
amount to the total dietary intake of those vitamins (i.e., more than 1 
to 2 percent). There are a number of commonly consumed foods that are 
substantial sources of vitamin E (e.g., certain nuts and oils, 
margarines) (Ref. 5); these foods are discussed in the reference cited 
by CFS. Substantial sources of thiamin include yeast breads, ready-to-
eat cereals, pastas and grains, certain meats, and milk (Ref. 5). 
Neither of the two vitamins particularly sensitive to irradiation, 
vitamin E and thiamin, has been identified as being present in 
relatively high amounts in fresh lettuce and/or fresh spinach and as 
contributing more than a trivial amount to the total dietary intake of 
these vitamins. Therefore, the information provided by CFS, that 
synergistic losses have been found for vitamin E, does not call into 
question our assessment of the nutritional impact of the final rule and 
determination that irradiating fresh lettuce and fresh spinach up to a 
maximum dose of 4.0 kGy is safe. Accordingly, we are denying CFS' 
objection and request for a hearing because the data and information 
submitted by CFS are insufficient to justify the factual determination 
urged, even if accurate (Sec.  12.24(b)(3)).

C. Second Numbered Objection: CFS' Assertion That FDA Underestimated 
the Nutritional Contribution of Fresh Spinach and Fresh Lettuce to the 
Diet

    CFS also objects that we underestimated the nutritional 
contribution of fresh lettuce and fresh spinach to the diet. 
Specifically, CFS states that we failed to consider spinach's 
``dramatically rising nutritional contribution'' to the average 
American diet over time and failed to consider subpopulations which 
rely more heavily on spinach for nutrition than the statistically 
average American. Thus, CFS attempts to call into question our 
assessment of the nutritional impact of the final rule and ultimately 
our determination that irradiating fresh lettuce and fresh spinach up 
to a maximum dose of 4.0 kGy is safe.
    According to CFS, we employed two criteria to consider which 
nutrients were assessed: (1) Nutrients for which spinach/iceberg 
lettuce are an ``excellent source;'' and (2) nutrients for which 
spinach/iceberg lettuce contribute greater than 1 to 2 percent of the 
statistically average American's diet. CFS asserts that we should have 
provided a rationale for considering only nutrients for which spinach 
is an ``excellent source'' and should have considered vitamins for 
which spinach is also a ``good source.'' CFS has mischaracterized the 
criteria we used for our nutritional assessment, which was explained in 
our nutrition memorandum (Ref. 2). We explained in the nutrition 
memorandum that we considered all vitamins known to be present in 
lettuce and spinach in relatively high amounts (greater than or equal 
to 10 percent of the daily value for vitamins), including vitamins for 
which lettuce and/or spinach were ``good'' or ``excellent'' sources, 
and that contribute greater than 1 to 2 percent to the total dietary 
intake of those vitamins. Vitamins that did not meet these two criteria 
were not explicitly discussed in the nutrition memorandum. While fresh 
spinach is a ``good source'' of vitamin E, vitamin B6, and 
riboflavin, fresh spinach did not contribute more than 1 to 2 percent 
to the total dietary intake of these vitamins. Therefore, we did not 
explicitly discuss these nutrients in the nutrition memorandum. CFS has 
not presented any evidence to call into question the criteria we used 
for our nutritional assessment. Therefore, we are denying CFS' 
objection and request

[[Page 10361]]

for a hearing because a hearing will not be granted on the basis of 
mere allegations or denials or general descriptions of positions and 
contentions (Sec.  12.24(b)(2)).
    In addition, CFS objects to our second criteria, asserting that we 
rely on a ``13-year old `snapshot' that misses the growing importance 
of [spinach] to the nutritional adequacy of American diets.'' In 
support of this objection, CFS submitted a study performed by the 
Economic Research Service (ERS) of the United States Department of 
Agriculture (USDA) (Ref. 26). This study provides basic economic 
information about the market distribution of spinach in the United 
States. CFS points out that this study indicated an increase in the 
consumption of spinach from the 1970s through 2002. Table 1 of the ERS 
study presents ``per capita use'' \10\ of spinach in the United States. 
The per capita use values for fresh market (i.e., fresh spinach) for 
1994, 1995, and 1996 are 0.75, 0.67, and 0.63 pounds, respectively, and 
the corresponding per capita use values for total spinach are 1.71, 
1.66, and 1.77 pounds, respectively. While CFS focused on the value for 
per capita use of total spinach, the fresh market value is more 
pertinent to this discussion, as fresh spinach is the subject of this 
regulation. The ERS study indicates that the total fresh market per 
capita value for spinach increased from 0.75 pounds in 1994 to 1.49 
pounds in 2002. CFS asserts that we did not consider this increase in 
fresh spinach consumption in the nutritional assessment.
---------------------------------------------------------------------------

    \10\ ``Per capita use'' was calculated using two major datasets 
on food consumption in the United States: (1) Food disappearance 
data, which measures the flow of raw and semi-processed food 
commodities through the U.S. marketing system, and (2) the 
Continuing Survey of Food Intakes by Individuals, which records food 
intake over a specific period and collects demographic information, 
information on where a food item was purchased, how it was prepared, 
and where it was eaten (Ref. 26).
---------------------------------------------------------------------------

    CFS further asserts that this rise in consumption of spinach could 
be used to provide a rough approximation of the dietary and nutritional 
contribution of spinach during these years (i.e., 1997 to 2002). CFS 
provides estimations for percent contribution of spinach to vitamin A 
and vitamin C intake and suggests that contributions of spinach to 
vitamin E, riboflavin, and vitamin B6 intake may have 
increased to provide more than 1 to 2 percent of the percent daily 
value as well.
    However, we note that our nutritional assessment included a key 
conservative assumption that compensates for the increase in fresh 
spinach consumption cited by the ERS study. Specifically, we assumed 
that all spinach and iceberg lettuce in the food supply would be 
irradiated (i.e., 100 percent commercial application). For the years of 
1994, 1995, and 1996, we conservatively estimated 100 percent 
commercial application; values for total per capita use of spinach were 
1.71, 1.66, and 1.77 pounds, respectively, during those years, and we 
assumed all spinach could be irradiated when evaluating the nutritional 
impact of irradiating fresh lettuce and fresh spinach. These values for 
total per capita use of spinach each exceed the value for fresh market 
consumption in 2002 and therefore, our assessment encompassed the 
increased per capita use of fresh spinach through use of this 
conservative approach. Since our approach did not underestimate fresh 
spinach consumption in our nutritional assessment, the data and 
information provided by CFS do not call into question our assessment of 
the nutritional impact of the final rule and determination that 
irradiating fresh lettuce and fresh spinach up to a maximum dose of 4.0 
kGy is safe. Moreover, CFS' assertion that the rise in spinach 
consumption indicates increased contributions of spinach to the dietary 
intake of vitamins is not based on actual data. The estimates provided 
by CFS are purely speculative; the estimates do not account for recent 
changes in calculation of vitamin A equivalency and presume no other 
changes in the U.S. diet (during the same time period) related to 
intakes of other foods containing vitamin A and provitamin A and 
certain water-soluble vitamins listed by CFS. Because the data and 
information submitted by CFS are insufficient to justify the factual 
determination urged, even if accurate (Sec.  12.24(b)(3)), and a 
hearing will not be granted on the basis of mere allegations or denials 
or general descriptions of positions and contentions (Sec.  
12.24(b)(2)), we are denying CFS' objection and request for a hearing.
    CFS also objects to the final rule by alleging that we did not 
consider atypical consumers of spinach such as Asian women, women 60 
years of age or older, and vegetarians. We are aware that there is 
variation in the amount of fresh spinach consumed by different U.S. 
subpopulations; however, CFS provided no evidence that spinach is a 
more significant source of certain vitamins for any particular 
subpopulation. Indeed, to establish the contribution and significance 
of spinach as a source of specific vitamins in the diet, the complete 
diet must be considered. For example, when assessing the relative 
contribution of spinach and other leafy greens to the vitamin A content 
of the diet, the dietary intake of other major contributors of vitamin 
A (including vitamin A rich foods such as organ meats and dairy 
products) and provitamin A rich foods (such as carrots, tomatoes, and 
fortified ready-to-eat cereals) should be included. In addition, 
according to the IOM, bioavailability of provitamin A carotenoids 
should be taken into account. In the absence of data on the complete 
diet, it is not possible to determine the percent contribution of 
spinach and lettuce to the dietary intake of vitamins for these 
population subgroups and whether the relative contribution of spinach 
and lettuce to the dietary intake of these vitamins varies for the 
subpopulations cited by CFS. While the ERS study indicates that Asian 
women and women 60 years of age or older consume a relatively greater 
amount of fresh spinach compared to statistically average Americans, 
CFS did not establish that the small losses of some vitamins that could 
result from the petitioned use of irradiation of fresh spinach would be 
nutritionally significant (i.e., exceed a trivial amount for the total 
diet) for any of these population subgroups. Thus, the information 
provided by CFS regarding certain subpopulations that consume more 
spinach is not sufficient to support CFS' assertion that we failed to 
protect ``atypical'' consumers and therefore underestimated the 
nutritional contribution of fresh lettuce and fresh spinach to the 
diet. We are denying CFS' objection and request for a hearing because 
the data and information submitted by CFS are insufficient to justify 
the factual determination urged, even if accurate (Sec.  12.24(b)(3)).

D. Third Numbered Objection: CFS' Contention That FDA Failed To Conduct 
a Cumulative Assessment of Irradiation-Induced Nutrient Loss

    CFS also objects that we ``failed to conduct a cumulative 
assessment of irradiation-induced nutrient losses in fresh spinach and 
iceberg lettuce in combination with irradiation-induced nutrient losses 
in other foods already approved for irradiation * * *.'' CFS contends 
that by ``breaking out'' fresh lettuce and fresh spinach from the 
original petition, the nutritional impact will appear lessened, even if 
the impact of irradiating all the foods covered in the original 
petition is significant. Accordingly, CFS believes that we should 
conservatively assume that the entire supply of any given food will be 
irradiated at the maximum permitted dose when approving a petition. 
CFS'

[[Page 10362]]

contention therefore attempts to call into question our assessment of 
the nutritional impact of the final rule and our determination that 
irradiating fresh lettuce and fresh spinach up to a maximum dose of 4.0 
kGy is safe.
    We explained in the final rule our criteria for evaluating whether 
irradiation of fresh lettuce and fresh spinach up to a maximum dose of 
4.0 kGy would have an adverse effect on the nutritional quality of the 
diet. Our analysis focused on the effects of irradiation on those 
nutrients for which at least one of these foods may be identified as an 
``excellent source'' or a ``good source'' and for which they contribute 
more than a trivial amount to the total dietary intake (i.e., the 
nutrients that had the potential to impact the diet). We based our 
decision on both the data and information submitted in the petition, as 
well as other data and information in our files. We determined that, 
based on the available data and information, the effects of irradiation 
on nutrient levels in fresh lettuce and fresh spinach treated under the 
proposed conditions will be insignificant and will not adversely affect 
the nutritional quality of the overall U.S. diet.
    CFS alleges that ``breaking out'' fresh lettuce and fresh spinach 
from the foods covered in the original petition lessens the apparent 
overall nutritional impact of irradiated foods. However, the vitamin 
loss resulting from this regulation is negligible and therefore will 
not affect any cumulative assessment. CFS also asserts that we should 
conservatively assume that the entire supply of any given food will be 
irradiated at the maximum permitted dose during the approval of a 
petition. We agree with CFS and have chosen to employ this approach 
when assessing nutritional losses induced by irradiation. The nutrition 
memorandum notes that we, in our reviews and analysis of nutritional 
data, operate under the assumption that the entire supply of a given 
food may be irradiated at the maximum permitted dose. Contrary to what 
CFS appears to assert, the discussion of data at lower doses in the 
nutrition memorandum does not negate this assumption; rather, it 
reflects a review of published data on irradiation of various plant 
foods at both lower and higher doses. CFS has not submitted sufficient 
information to support the conclusion that nutrient loss in fresh 
lettuce or fresh spinach irradiated under the petitioned conditions, in 
combination with nutrient losses in other foods already approved for 
irradiation, would call into question our assessment of the nutritional 
impact of the final rule and would be a safety concern. Accordingly, we 
are denying CFS' objection and request for a hearing because a hearing 
will not be held on the basis of mere allegations or denials or general 
descriptions of positions or contentions (Sec.  12.24(b)(2)).

E. Fourth Numbered Objection: CFS' Assertion That FDA Failed To 
Determine Risk of Food-Borne Disease From Radiation Resistant Pathogens

    In another overall objection to the final rule, CFS objects to our 
safety evaluation of irradiated fresh lettuce and fresh spinach, 
stating that ``FDA has failed to determine whether irradiation of fresh 
spinach and iceberg lettuce . . . will increase the risk of food-borne 
disease from radiation-insensitive pathogens such as Clostridium 
botulinum. . . .'' Specifically, CFS asserts that our analysis did not 
adequately address the possibility that the suppression of radiation-
sensitive bacteria by irradiation might offer enhanced growth 
conditions for pathogens that are more resistant to irradiation, such 
as C. botulinum (the bacterium that produces the toxin which causes the 
disease botulism). CFS presents three arguments to support this 
objection: (1) We did not provide a discussion of radiation-insensitive 
pathogens other than C. botulinum; (2) the study by Petran et al. (Ref. 
27), which we cited to support our conclusion that irradiation will not 
increase the risk of botulism, did not involve irradiation of fresh 
lettuce or fresh spinach; and (3) the microbiology memorandum (Ref. 28) 
contained contradictory statements. We will address each argument in 
this document.
    First, CFS asserts that we erred by not evaluating irradiation's 
potential effect on radiation-insensitive pathogens other than C. 
botulinum. Historically, it has been our practice to evaluate 
microbiological pathogens that have been identified as a potential 
hazard for a specific type of food and which are also of public health 
significance (see, for example, 70 FR 48057, August 16, 2005 (amending 
the food additive regulations to provide for the safe use of ionizing 
radiation for control of Vibrio species and other food-borne pathogens 
in fresh or frozen molluscan shellfish); 65 FR 64605, October 30, 2000 
(amending the food additive regulations to provide for the safe use of 
ionizing radiation to control microbial pathogens in seeds for 
sprouting); 65 FR 45280, July 21, 2000 (amending the food additive 
regulations to provide for the safe use of ionizing radiation for the 
reduction of Salmonella in fresh shell eggs); 62 FR 64107, December 3, 
1997 (amending the food additive regulations to provide for the safe 
use of a source of radiation to treat refrigerated or frozen uncooked 
meat, meat byproducts, and certain meat food products to control food-
borne pathogens and extend product shelf life); 55 FR 18538, May 2, 
1990 (amending the food additive regulations to provide for the safe 
use of sources of ionizing radiation for the control of food-borne 
pathogens in poultry); and 50 FR 29658, July 22, 1985 (amending the 
food additive regulations to permit gamma radiation treatment of pork 
to control Trichinella spiralis)). In the microbiology memorandum, we 
provide a discussion of the food-borne disease outbreaks and pertinent 
pathogens most commonly associated with the consumption of fresh 
lettuce and fresh spinach. The microbiology memorandum identifies 
Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella 
enterica serovars as pathogens of public health significance, and 
discussed these pathogens in detail. We also discuss C. botulinum in 
the microbiology memorandum and in the final rule, not because C. 
botulinum has been identified as a reasonable hazard for either fresh 
lettuce or fresh spinach, but because this pathogen has been identified 
as being both radiation-insensitive and of public health significance, 
and to demonstrate the impact that elimination of native microflora may 
have on the ability of this type of pathogen to proliferate and 
elaborate toxin. However, it is not our burden to discuss possibly 
irrelevant pathogens. CFS does not provide information related to 
additional radiation-insensitive pathogens of public health 
significance that may be present in fresh lettuce or fresh spinach that 
we have not considered, and the objection contains no information that 
would cause us to change our safety determination. We are therefore 
denying CFS' objection and request for a hearing because a hearing will 
not be granted on the basis of mere allegations or denials or general 
descriptions of positions and contentions (Sec.  12.24(b)(2)).
    Second, CFS asserts that the Petran et al. study (Ref. 27), which 
we cited in support of our conclusion that irradiation will not 
increase the risk of botulism, did not involve irradiation of fresh 
lettuce or fresh spinach, and therefore, did not address the safety 
concern that irradiation may provide enhanced growing conditions for 
radiation-insensitive pathogens due to the ``elimination'' of spoilage 
and other

[[Page 10363]]

bacteria. CFS also objects to the final rule based on this study 
because C. botulinum multiplies more rapidly on shredded cabbage than 
romaine lettuce, asserting that this observation demonstrates that 
pathogens can have markedly different growth patterns on different 
vegetables, underscoring the illegitimacy of extrapolating from data on 
one vegetable to another.
    The Petran et al. study (Ref. 27) assesses the potential for growth 
and toxin production of heat-shocked C. botulinum spores in fresh-cut 
romaine lettuce and shredded cabbage. While the produce was not 
irradiated, the study was chosen because it offers a non-competitive 
environment for C. botulinum elaboration, reflecting conditions that 
would be generated if produce were irradiated in the presence of C. 
botulinum spores. C. botulinum is a Gram-positive anaerobic 
sporeformer, and this study examined the potential for outgrowth and 
toxin production under conditions of temperature abuse in both aerobic 
and anaerobic conditions. As stated in our microbiology memorandum, 
there was no toxin production detected in either the vented or non-
vented packaging at 12.7 [deg]C (~55 [deg]F) or lower after 28 days. 
Toxin was produced only under conditions of extreme temperature abuse 
after all samples became unmistakably inedible, i.e., after 14 days at 
21 [deg]C (~70 [deg]F). The study demonstrated that even under ideal 
growth conditions for C. botulinum where the levels of native 
microflora were greatly reduced, toxin production was not elaborated 
until after the produce was clearly inedible. Moreover, CFS has not 
presented evidence or a rationale that changes our conclusion that the 
``growth and toxin expression by Gram-positive anaerobic sporeformers 
would not present a likely additional hazard in this application of 
irradiation.''
    CFS also objects to the use of the Petran et al. study because it 
did not involve fresh lettuce or fresh spinach; rather, the study 
explored the potential for growth and toxin production by C. botulinum 
in samples of romaine lettuce and cabbage packaged in aerobic and 
anaerobic conditions exposed to temperature abuse, which represent 
ideal conditions for growth and toxin production by C. botulinum. CFS 
uses the example of C. botulinum multiplying more rapidly on shredded 
cabbage than on romaine lettuce as evidence that one cannot extrapolate 
from data on one type of leafy green vegetable to draw conclusions 
about other leafy green vegetables (i.e., fresh lettuce and fresh 
spinach). We recognize that in the study, toxin was produced in the 
non-vented cabbage sample after 7 days of storage at 21 [deg]C (nearly 
70 [deg]F), a timeframe that was shorter than the timeframe for toxin 
production in romaine lettuce. However, we do not agree that these 
results indicate the illegitimacy of extrapolating data from one type 
of leafy green vegetable to another leafy green vegetable. CFS fails to 
note that all of the samples for which toxin production was observed 
were clearly inedible prior to toxin production, and that toxin was not 
produced for at least 28 days in any of the samples that were vented. 
Indeed, the study demonstrated that it is extremely unlikely for an 
anaerobic sporeformer to grow and produce toxin in lettuce products 
that are handled properly (i.e., not stored at 70 [deg]F for 7 days) 
and are of acceptable quality for consumption. Furthermore, all leafy 
green vegetables (e.g., iceberg lettuce, spinach, romaine lettuce, and 
cabbage) are grown and harvested under similar conditions and therefore 
the probability of contamination with C. botulinum is similar. As 
stated in the microbiology memorandum, this type of contamination is 
unlikely. CFS did not provide any data to demonstrate that C. botulinum 
has been identified as a hazard in green leafy vegetables or that the 
likelihood of toxin production would be greater for either fresh 
lettuce or fresh spinach than it is in romaine lettuce or cabbage. CFS' 
objection did not include any new information or data that would call 
into question our findings about this study. Accordingly, the 
information provided by CFS, that the Petran et al. study did not 
involve the irradiation of fresh lettuce or fresh spinach, is not 
sufficient to call into question our determination that irradiating 
fresh lettuce and fresh spinach up to a maximum dose of 4.0 kGy is 
safe. We are therefore denying CFS' objection and request for a hearing 
because the data and information submitted by CFS are insufficient to 
justify the factual determination urged, even if accurate (Sec.  
12.24(b)(3)).
    Further, it is important to note that the standards of 
microbiological safety of fresh lettuce and fresh spinach are 
independent of the final rule permitting the irradiation of fresh 
lettuce and fresh spinach. Irradiation is just one potential control 
contributing to the mitigation of food-borne pathogens, and its 
intended technical effect is to reduce, not eliminate, spoilage and 
pathogenic bacteria. Therefore, the final rule is not predicated on 
irradiation, by itself, resulting in fresh lettuce and fresh spinach 
that are pathogen-free.
    The final portion of the CFS objection contends that the our 
microbiology memorandum contains contradictory statements, and 
therefore, the question of whether the growth of C. botulinum or other 
radiation-insensitive pathogens present on irradiated fresh lettuce or 
fresh spinach would be enhanced by the suppression of competing 
bacteria remains unanswered. CFS asserts that when discussing the 
Petran et al. study, the microbiology memorandum states that the 
spoilage microorganisms ``attain previous levels within days of 
treatment,'' but when discussing the Zhang et al. study (2006) (Ref. 
29), the memorandum states that ``relative reductions [in numbers of 
viable bacteria during 9 days of storage] persisted . . .'' CFS 
contends that these statements are contradictory and that our 
conclusion that spoilage microorganisms ``attain previous levels within 
days of treatment'' is erroneous.
    CFS' objection implies that both statements cannot be true and that 
we misinterpreted the Zhang et al. study. However, we disagree that 
either statement is false. The Zhang et al. study (Ref. 29) reported 
substantially lower total bacterial counts for the irradiated samples 
as compared to the unirradiated control on the same day. Our 
microbiology memorandum's statement that ``relative reductions [in 
numbers of viable bacteria during 9 days of storage] persisted . . .'' 
is, therefore, correct. However, while these lower levels of bacteria 
persisted, the native microflora was also recovering as evidenced 
through the increase in total bacterial counts over the storage period. 
In the case of the 0.5 kGy and 1.0 kGy irradiation trials, bacterial 
counts attained initial levels (i.e., the control level on day zero) 
within days of treatment. For the 1.5 kGy sample, the total bacterial 
counts did not reach the control level by the end of the 9-day storage 
period, but the total bacterial counts increased as storage time 
increased. The results of the 1.5 kGy sample therefore demonstrate the 
veracity of both of the memorandum's statements: The native microflora 
was able to recover and the substantially lower bacterial counts 
persisted throughout the 9-day storage period. At the end of the 9-day 
storage period, the unirradiated control was reported to have 7.60 Log 
CFU/g \11\ or approximately 4 million colony forming units per gram, 
which resulted in the spoilage of tissue. On the same day, the

[[Page 10364]]

sample irradiated at 1.5 kGy contained approximately 50 thousand colony 
forming units per gram, which was lower than the unirradiated control, 
but significantly larger than the nearly 200 colony forming units that 
were present immediately following irradiation. Thus, the statements in 
the microbiology memorandum are both correct, and we maintain that the 
memorandum accurately and reliably reflects the information in the 
cited publication. Accordingly, we are denying CFS' objection and 
request for a hearing because the data and information submitted by CFS 
are insufficient to justify the factual determination urged, even if 
accurate (Sec.  12.24(b)(3)).
---------------------------------------------------------------------------

    \11\ The data were obtained by calculating the log of the colony 
forming units per gram (LogCFU/g). Therefore, any whole number 
reported is indicative of magnitude.
---------------------------------------------------------------------------

F. Fifth Numbered Objection: CFS' Contention That FDA Failed To 
Consider Alternatives to Irradiation of Fresh Lettuce and Fresh Spinach

    CFS' final objection contends that we have failed to consider 
alternatives to irradiation of fresh lettuce and fresh spinach. 
However, we evaluate a particular food additive only for its safety. 
Section 409(c)(1) of the FD&C Act requires FDA to establish a 
regulation prescribing, with respect to one or more proposed uses of 
the food additive involved, the conditions under which such additive 
may be safely used. The FD&C Act does not require us to consider 
alternatives as a factor in deciding whether to grant a food additive 
petition. We evaluated the safety of irradiating fresh lettuce and 
fresh spinach at a maximum dose not to exceed 4.0 kGy based on three 
appropriate areas relevant to safety: (1) Potential toxicity; (2) 
nutritional adequacy; and (3) effects on the microbiological profile of 
the treated food. Based on the data and studies submitted in the 
petition and other information in our files, we properly concluded that 
the proposed use of irradiation to treat fresh lettuce and fresh 
spinach with absorbed doses that will not exceed 4.0 kGy is safe. 
Therefore, we are denying CFS' objection and request for a hearing 
because CFS raises a factual issue that is not determinative with 
respect to the action requested (e.g., the action would be the same 
even if the factual issue were resolved in the way sought) (Sec.  
12.24(b)(4)).

G. FWW's Assertion That FDA Failed To Address Potential Organoleptic 
Degradation

    FWW submitted objections to the final rule in a letter dated 
September 22, 2008, which concurred with objections put forth by CFS, 
and included an additional objection. FWW asserts that there is a basis 
to stay the approval of the final rule and to convene a public 
evidentiary hearing on the issue of the quality of the irradiated 
produce at the dose levels approved and whether there is technology 
currently available to achieve the pathogen reduction desired while 
still preserving the organoleptic properties of the produce. FWW 
asserts that approval of this petition raises issues of safety and 
deception to the consumer under section 409 of the FD&C Act because 
irradiating fresh lettuce and fresh spinach at the petitioned doses may 
result in organoleptic degradation and may not achieve pathogen 
reduction.
    In support of its objection, FWW cites a 2008 study by Gomes et al. 
(Ref. 30), which according to FWW, demonstrated that doses higher than 
1 kGy were necessary to ensure elimination of food-borne pathogens from 
bagged spinach leaves. Additionally, FWW quotes Dr. Mike Doyle, 
Director of the Center for Produce Safety at the University of Georgia, 
who stated that, ``in a commercial processing plant, products are 
stacked in cartons for treatment, so the dose must be strong enough to 
irradiate every part of the package and that could lead to some 
products being `overly treated,' which could render the product 
unappetizing.'' Thus, FWW asserts that pathogen reduction may require 
strong irradiation doses that will result in organoleptic degradation.
    It appears from the objection that FWW has misinterpreted the 
intended technical effect from irradiation of fresh lettuce and fresh 
spinach to be the elimination of microbial contamination instead of the 
control of microbial contamination, as stated in the final rule. FWW 
provides no information to call into question our conclusions that the 
irradiation of fresh lettuce and fresh spinach is safe and will achieve 
the intended technical effect of controlling microbial contamination at 
doses not to exceed 4.0 kGy. In addition, we acknowledge that 
radiation-induced chemical changes, if sufficiently large, may cause 
changes in the organoleptic properties of the food. However, such 
organoleptic changes do not necessarily render the food unsafe, and FWW 
has not provided any evidence that would establish a link between 
organoleptic changes and the safety of irradiated foods. Moreover, food 
processors have an incentive to minimize the extent of the chemical 
changes in the food to avoid undesirable effects on taste, odor, color, 
or texture. Therefore, we are denying FWW's objection and request for a 
hearing because a hearing will not be granted on the basis of mere 
allegations or denials or general descriptions of positions and 
contentions (Sec.  12.24(b)(2)).
    FWW also asserted that irradiation is not effective against all 
food-borne pathogens (e.g., viruses) and could lead consumers to an 
incorrect conclusion that a product is safe even though it may still be 
contaminated. While we recognize that irradiation is not effective 
against viruses, the final rule permitting the irradiation of fresh 
lettuce and fresh spinach up to a maximum dose of 4.0 kGy is not 
predicated on the irradiation treatment eliminating all potential 
pathogens. In the final rule, we concluded that the use of irradiation 
up to a maximum dose of 4.0 kGy on fresh lettuce and fresh spinach was 
safe. During the review, we considered chemical, toxicological, 
nutritional, and microbiological effects resulting from the application 
of ionizing radiation to fresh lettuce and fresh spinach. It was 
demonstrated that the petitioned use of irradiation would not raise 
safety concerns and that the treatment achieved its intended technical 
effects (i.e., reduction of microorganisms and extension of shelf 
life). Therefore, we are denying FWW's objection and request for a 
hearing. FWW has not provided any evidence to demonstrate that the 
final rule would lead consumers to an incorrect conclusion that a 
product is safe even though it may still be contaminated; a hearing 
will not be granted on the basis of mere allegations or denials or 
general descriptions of positions and contentions (Sec.  12.24(b)(2)). 
In addition, FWW's assertion that irradiation is not effective against 
all food-borne pathogens is not determinative with respect to the 
action requested; a hearing will not be granted unless resolution of 
the factual issue in the way sought is adequate to justify the action 
requested (Sec.  12.24(b)(4)).

V. Summary and Conclusion

    Section 409 of the FD&C Act requires that a food additive be shown 
to be safe before marketing. Under 21 CFR 170.3(i), a food additive is 
``safe'' if ``there is a reasonable certainty in the minds of competent 
scientists that the substance is not harmful under the intended 
conditions of use.'' In our August 22, 2008, final rule approving the 
use of irradiation of fresh lettuce and fresh spinach up to a maximum 
dose of 4.0 kGy, we concluded, based on our evaluation of the data 
submitted in the petition and other relevant material, that the 
petitioned use of irradiation is safe for its intended use for the 
control of food-borne pathogens and extension of shelf life in fresh 
lettuce and fresh spinach.

[[Page 10365]]

    The petitioner has the burden to demonstrate the safety of the 
additive to gain FDA approval. However, once we make a finding of 
safety in an approval document, the burden shifts to an objector, who 
must come forward with evidence that calls into question our conclusion 
(see section 409(f)(1) of the FD&C Act).
    CFS and FWW have not established that we overlooked or 
misinterpreted significant information in the record to reach our 
conclusion that the use of irradiation up to a maximum dose of 4.0 kGy 
for control of food-borne pathogens and extension of shelf life in 
fresh lettuce and fresh spinach is safe. Therefore, we have determined 
that the final rule should not be modified or revoked based on the 
objections. We are also denying the requests for a hearing because the 
objections do not meet the standard for granting a hearing as discussed 
in this document. In addition, FWW's request for a stay of the 
effectiveness of the August 22, 2008, regulation until a hearing is 
held is moot because we are denying all hearing requests. Thus, we are 
confirming August 22, 2008, as the effective date of the regulation.

VI. References

    The following sources are referred to in this document. References 
marked with an asterisk (*) have been placed on display at the Division 
of Dockets Management (HFA-305), Food and Drug Administration, 5630 
Fishers Lane, Rm. 1061, Rockville, MD 20852, under Docket No. FDA-1999-
F-2405 (formerly 1999F-5522) and may be seen by interested persons 
between 9 a.m. and 4 p.m., Monday through Friday, and are available 
electronically at http://www.regulations.gov. References without 
asterisks are not on display; they are available as published articles 
and books.

1. WHO, ``Safety and Nutritional Adequacy of Irradiated Food,'' 
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*2. Memorandum for FAP 9M4697 from A. Edwards, FDA, to L. 
Highbarger, FDA, dated July 16, 2008.
3. Institute of Medicine, Dietary Reference Intakes for Vitamin A, 
Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, 
Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc, National 
Academies Press, Washington, DC, 2001.
4. Institute of Medicine, Dietary Reference Intakes for Vitamin C, 
Vitamin E, Selenium, and Carotenoids, National Academies Press, DC, 
2000.
*5. Cotton, P. A., A. F. Subar, J. E. Friday, et al., ``Dietary 
Sources of Nutrients Among U.S. Adults, 1994 to 1996,'' Journal of 
the American Dietetic Association, 104:921-930, 2004.
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Joint FAO/IAEA/WHO Expert Committee,'' World Health Organization 
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*7. Memorandum to the file, FAP 4M4428, D. Hattan, Acting Director, 
Division of Health Effects Evaluation, dated November 20, 1997.
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on Folates in Food,'' Lebenson Wiss Technology-Food Science and 
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*14. Richardson, L. R., S. Wilkes, and S. J. Ritchey, ``Comparative 
Vitamin K Activity of Frozen, Irradiated and Heat-Processed Foods,'' 
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*15. Richardson, L. R., P. Woodworth, and S. Coleman, ``Effect of 
Ionizing Radiation on Vitamin K,'' Federation Proceedings, 
15(3):924-926, 1956.
*16. Metta, V. C., M. S. Mameesh, and B. C. Johnson, ``Vitamin K 
Deficiency in Rats Induced by Feeding of Irradiated Beef,'' Journal 
of Nutrition, 69:18-22, 1959.
*17. Hirayama, K., K. Uetsuka, Y. Kuwabara, et al., ``Vitamin K 
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Sterilized by [gamma]-Irradiation,'' Experimental Animals, 
56(4):273-278, 2007.
18. Diehl, J. F., ``Chemical Effects of Ionizing Radiation,'' pp. 
43-88 in Safety of Irradiated Foods, 2nd ed., Marcel Dekker, Inc., 
New York, 1995.
19. Combs, G. F. Jr., The Vitamins. 3rd ed. Burlington: Elsevier 
Academic Press, 2008.
20. FAO/WHO, ``Human Vitamin and Mineral Requirements,'' Report of a 
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Expert Consultation, Bangkok, Thailand. Rome: FAO/WHO, 2002.
*21. Booth, S. L. and J. W. Suttie, ``Dietary Intake and Adequacy of 
Vitamin K,'' Journal of Nutrition, 128:785-788, 1998.
22. WHO IARC, ``Vitamin K Substances,'' IARC Monographs on the 
Evaluation of Carcinogenic Risks to Humans, vol. 76, World Health 
Organization, Lyon, France, 2001.
23. FAO/IAEA/WHO, ``High Dose Irradiation: Wholesomeness of Food 
Irradiated With Doses Above 10kGy: Report of a Joint FAO/IAEA/WHO 
Study Group,'' World Health Organization Technical Report Series, 
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    Dated: February 19, 2014.
Leslie Kux,
Assistant Commissioner for Policy.
[FR Doc. 2014-03976 Filed 2-24-14; 8:45 am]
BILLING CODE 41640-01-P