[Federal Register Volume 59, Number 172 (Wednesday, September 7, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-21900]


[[Page Unknown]]

[Federal Register: September 7, 1994]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration

 21 CFR Part 177

[Docket No. 91F-0449]

 

Indirect Food Additives: Polymers

AGENCY: Food and Drug Administration, HHS.

ACTION: Final rule.

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SUMMARY: The Food and Drug Administration (FDA) is amending the food 
additive regulations to provide for the safe use of hydrogenated 
butadiene/acrylonitrile copolymers in repeated use food-contact 
articles. This action is in response to a petition filed by Polysar 
Rubber Corp.

DATES: Effective September 7, 1994; written objections and requests for 
a hearing by October 7, 1994. The Director of the Office of the Federal 
Register approves the incorporation by reference in accordance with 5 
U.S.C. 552(a) and 1 CFR part 51 of a certain publication in 21 CFR 
177.2600(c)(4)(i), effective September 7, 1994.

ADDRESSES: Submit written objections to the Dockets Management Branch 
(HFA-305), Food and Drug Administration, rm. 1-23, 12420 Parklawn Dr., 
Rockville, MD 20857.

FOR FURTHER INFORMATION CONTACT: Vir D. Anand, Center for Food Safety 
and Applied Nutrition (HFS-216), Food and Drug Administration, 200 C 
St. SW., Washington, DC 20204, 202-418-3081.

SUPPLEMENTARY INFORMATION: In a notice published in the Federal 
Register of December 19, 1991 (56 FR 65907), FDA announced that a food 
additive petition (FAP 2B4299) had been filed by Polysar Rubber Corp., 
1265 South Vidal St., Sarnia, Ontario, Canada N7T 7MI. The petition 
proposed that the food additive regulations be amended in Sec. 177.2600 
Rubber articles intended for repeated use (21 CFR 177.2600) to provide 
for the safe use of hydrogenated butadiene/acrylonitrile copolymers in 
repeated use food-contact articles.
    FDA, in its evaluation of the safety of this additive, reviewed the 
safety of the additive and the chemical impurities that may be present 
in the additive resulting from its manufacturing process. Although the 
additive itself has not been shown to cause cancer, it has been found 
to contain minute amounts of unreacted acrylonitrile, a carcinogenic 
reactant used in the manufacture of the additive. Residual amounts of 
reactants and manufacturing aids, such as acrylonitrile, are commonly 
found as contaminants in chemical products, including food additives.

 I. Determination of Safety

     Under section 409(c)(3)(A) of the Federal Food, Drug, and Cosmetic 
Act (the act) (21 U.S.C. 348(c)(3)(A), the so-called ``general safety 
clause'' of the statute, a food additive cannot be approved for a 
particular use unless a fair evaluation of the data available to FDA 
establishes that the additive is safe for that use. FDA's food additive 
regulations (21 CFR 170.3(i)) define ``safe'' as ``a reasonable 
certainty in the minds of competent scientists that the substance is 
not harmful under the intended conditions of use.''
     The anticancer or Delaney clause (section 409(c)(3)(A) of the act) 
further provides that no food additive shall be deemed safe if it is 
found to induce cancer when ingested by man or animal. Importantly, 
however, the Delaney clause applies to the additive itself and not to 
the impurities in the additive. That is, where an additive itself has 
not been shown to cause cancer, but contains a carcinogenic impurity, 
the additive is properly evaluated under the general safety clause 
using risk assessment procedures to determine whether there is a 
reasonable certainty that no harm will result from the proposed use of 
the additive (Scott v. FDA 728 F.2d 322 (6th Cir. 1984)).

 II. Safety of Petitioned Use of the Additive

     FDA estimates that the petitioned use of the additive, 
hydrogenated butadiene/acrylonitrile copolymer, will result in exposure 
to the additive of no greater than 7 parts per trillion (ppt) in the 
daily diet (Ref. 1).
     FDA does not ordinarily consider chronic toxicological testing to 
be necessary to determine the safety of an additive whose use will 
result in such low exposure levels (Ref. 2), and the agency has not 
required such testing here. However, the agency has reviewed the 
available toxicological data from acute toxicity studies on the 
additive. No adverse effects were reported in these studies.
     FDA has evaluated the safety of this additive under the general 
safety clause, considering all available data and using risk assessment 
procedures to estimate the upper-bound limit of risk presented by 
acrylonitrile, a carcinogenic chemical that may be present as an 
impurity in the additive. This risk evaluation of acrylonitrile has two 
aspects: (1) Assessment of the exposure to the impurity from the 
proposed use of the additive; and (2) extrapolation of the risk 
observed in the animal bioassays to the conditions of probable exposure 
to humans.

 A. Acrylonitrile

    FDA has estimated the worst-case exposure to acrylonitrile from the 
petitioned use of the additive in the manufacture of repeated use food-
contact articles to be 0.02 ppt of the daily diet (3 kilograms) or 0.06 
nanogram (ng) per person per day (Ref. 1). The agency used data from 
two carcinogenicity studies on acrylonitrile monomer fed to rats to 
estimate the upper-bound limit of lifetime human risk from exposure to 
this chemical stemming from the proposed use of hydrogenated butadiene/
acrylonitrile copolymers and the level of acrylonitrile that may be 
present in the additive (Ref. 3). The results of the bioassays on 
acrylonitrile monomer demonstrated that the material was carcinogenic 
for rats under the conditions of the studies. The test material caused 
significantly increased incidences of carcinogenic tumors at many 
tissue sites.
     Based on the estimated worst-case exposure of 0.06 ng per person 
per day, FDA estimates that the upper-bound limit of individual 
lifetime risk from the use of the hydrogenated butadiene/acrylonitrile 
copolymers is 8 x 10-11  or 8 in 100 billion (Ref. 4). Because of 
the numerous conservative assumptions used in calculating the exposure 
estimate, the actual lifetime averaged individual daily exposure to 
acrylonitrile is expected to be substantially less than the worst-case 
exposure, and therefore, the calculated upper-bound limit of risk would 
be less. Thus, the agency concludes that there is a reasonable 
certainty that no harm from exposure to acrylonitrile would result from 
the proposed use of hydrogenated butadiene/acrylonitrile copolymers.

B. Conclusion on Safety

     FDA has evaluated data in the petition and other relevant material 
and concludes that the proposed use of the additive in repeated use 
food-contact articles is safe. Based on this information, the agency 
has also concluded that the additive will have the intended technical 
effect. Therefore, Sec. 177.2600 should be amended as set forth below.

 C. Need for Specifications

     The agency has also considered whether a specification is 
necessary to control the amount of acrylonitrile impurity in the food 
additive. The agency finds that a specification is not necessary for 
the following reasons: (1) Because of the low level at which 
acrylonitrile may be expected to remain as an impurity following 
production of the additive, the agency would not expect this impurity 
to become a component of food at other than extremely small levels; and 
(2) the upper-bound limit of lifetime risk from exposure to this 
impurity, even under worst-case assumptions, is very low, less than 8 
in 100 billion.
    In accordance with Sec. 171.1(h) (21 CFR 171.1(h)), the petition 
and the documents that FDA considered and relied upon in reaching its 
decision to approve the petition are available for inspection at the 
Center for Food Safety and Applied Nutrition by appointment with the 
information contact person listed above. As provided in 21 CFR 
171.1(h), the agency will delete from the documents any materials that 
are not available for public disclosure before making the documents 
available for inspection.

 III. Environmental Impact

    The agency has carefully considered the potential environmental 
effects of this action. FDA has concluded that the action will not have 
a significant impact on the human environment, and that an 
environmental impact statement is not required. The agency's finding of 
no significant impact and the evidence supporting that finding, 
contained in an environmental assessment, may be seen in the Dockets 
Management Branch (address above) between 9 a.m. and 4 p.m., Monday 
through Friday.

 IV. Objections

    Any person who will be adversely affected by this regulation may at 
any time on or before October 7, 1994, file with the Dockets Management 
Branch (address above) written objections thereto. Each objection shall 
be separately numbered, and each numbered objection shall specify with 
particularity the provisions of the regulation to which objection is 
made and the grounds for the objection. Each numbered objection on 
which a hearing is requested shall specifically so state. Failure to 
request a hearing for any particular objection shall constitute a 
waiver of the right to a hearing on that objection. Each numbered 
objection for which a hearing is requested shall include a detailed 
description and analysis of the specific factual information intended 
to be presented in support of the objection in the event that a hearing 
is held. Failure to include such a description and analysis for any 
particular objection shall constitute a waiver of the right to a 
hearing on the objection. Three copies of all documents shall be 
submitted and shall be identified with the docket number found in 
brackets in the heading of this document. Any objections received in 
response to the regulation may be seen in the Dockets Management Branch 
between 9 a.m. and 4 p.m., Monday through Friday.

 V. References

     The following references have been placed on display in the 
Dockets Management Branch (address above) and may be seen by interested 
persons between 9 a.m. and 4 p.m., Monday through Friday.
     1. Memorandum from the Chemistry Review Branch (HFS-247) to the 
Indirect Additives Branch, FDA (HFS-216), concerning FAP 2B4299 
(Polysar Rubber Corp.) and exposure to the food additive and its 
component (acrylonitrile), November 24, 1992.
     2. Kokoski, C. J., ``Regulatory Food Additive Toxicology,'' in 
Chemical Safety Regulation and Compliance, edited by F. Homburger, 
J. K. Marquis, and S. Karger, New York, NY, pp.24-33, 1985.
     3. Memorandum of the Cancer Assessment Committee, Center for 
Food Safety and Applied Nutrition, FDA, on ``Acrylonitrile Risk 
Assessment,'' dated November 24, 1981.
     4. Memorandum from the Quantitative Risk Assessment Committee, 
Center for Food Safety and Applied Nutrition, FDA, concerning 
acrylonitrile (FAP 2B4299), dated April 19, 1993.

 List of Subjects in 21 CFR Part 177

     Food additives, Food packaging, Incorporation by reference.
     Therefore, under the Federal Food, Drug, and Cosmetic Act and 
under authority delegated to the Commissioner of Food and Drugs, 21 CFR 
part 177 is amended as follows:

PART 177--INDIRECT FOOD ADDITIVES: POLYMERS

     1. The authority citation for 21 CFR part 177 continues to read as 
follows:

    Authority: Secs. 201, 402, 409, 721 of the Federal Food, Drug, 
and Cosmetic Act (21 U.S.C. 321, 342, 348, 379e).

     2. Section 177.2600 is amended in paragraph (c)(4)(i) by 
alphabetically adding a new entry to read as follows:


Sec. 177.2600  Rubber articles intended for repeated use.

 * * * * *
     (c) * * *
     (4) * * *
     (i) * * *
    Hydrogenated butadiene/acrylonitrile copolymers (CAS Reg. No. 
88254-10-8) produced when acrylonitrile/butadiene copolymers are 
modified by hydrogenation of the olefinic unsaturation to leave not 
more than 10 percent trans olefinic unsaturation and no 
,-olefinic unsaturation as determined by a method 
entitled ``Determination of Residual ,-Olefinic and 
Trans Olefinic Unsaturation Levels in HNBR,'' developed October 1, 
1991, by Polysar Rubber Corp., 1256 South Vidal St., Sarnia, Ontario, 
Canada N7T 7MI, which is incorporated by reference in accordance with 5 
U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from the 
Division of Petition Control, Center for Food Safety and Applied 
Nutrition (HFS-215), Food and Drug Administration, 200 C St. SW., 
Washington, DC 20204, or may be examined at the Office of the Federal 
Register, 800 North Capitol St. NW., suite 700, Washington, DC.
* * * * *
    Dated: August 24, 1994.
William K. Hubbard,
Interim Deputy Commissioner for Policy.
[FR Doc. 94-21900 Filed 9-6-94; 8:45 am]
BILLING CODE 4160-01-F