[Federal Register Volume 60, Number 186 (Tuesday, September 26, 1995)]
[Notices]
[Pages 49602-49605]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-23844]



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ENVIRONMENTAL PROTECTION AGENCY

[OW-FRL-5298-6]


Availability of Information Document on Aquatic Life Toxicity

AGENCY: Environmental Protection Agency.

ACTION: Notice of availability of an information document on aquatic 
life toxicity for Di-2-Ethylhexyl Phthalate (DEHP).

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SUMMARY: The U.S. Environmental Protection Agency (EPA) is announcing 
the availability of an information document on aquatic life toxicity 
for Di-2-Ethylhexyl Phthalate (DEHP). Ambient water quality criteria 
documents are developed pursuant to Section 304(a)(1) of the Clean 
Water Act. The current guidelines for ambient water quality criteria 
for the protection of aquatic life specify the data needed for 
development of a national criteria. Sufficient acute and chronic 
toxicity data for DEHP were not available to derive a national 
criteria. For this reason, EPA is announcing the availability of an 
information document which presents only lowest observed effect levels 
(LOEL's) for DEHP.
    The group of chemicals commonly referred to as phthalates are 
esters of phthalic acid. Phthalates are used in the manufacture of 
plastics where they increase the flexibility, extensibility and 
workability of plastic. Di-2-Ethylhexyl Phthalate is the Phthalate 
compound that is produced in the largest volume.

ADDRESSES: A copy of the comments/responses and supporting documents 
(cited in the Reference section of this document) are available for 
review at EPA's Water Docket, 401 M Street, SW., Washington, DC 20460. 
For access to Docket materials, call (202) 260-3027 between 9 a.m. and 
3:30 p.m. for an appointment.
    Requests for copies of the supporting documents should be sent to: 
U.S. Environmental Protection Agency, National Center for Environmental 
Publications and Information, 11029 Kenwood Road, Cinncinati, OH 45242, 
(513) 489-8190, Internet address: [email protected].

FOR FURTHER INFORMATION CONTACT: Mr. Patrick Ogbebor, Health and 
Ecological Criteria Division (4304), U.S. Environmental Protection 
Agency, 401 M Street, SW., Washington, DC 20460, (202) 260-0658.

[[Page 49603]]


SUPPLEMENTARY INFORMATION:

Background

    EPA publishes and periodically updates ambient water quality 
criteria pursuant to Section 304(a)(1) of the Clean Water Act, 33 
U.S.C. 1314(a)(1). These criteria are intended to reflect the latest 
scientific knowledge on the identifiable effects of pollutants on 
public health and welfare, aquatic life and recreation. Beginning in 
1973, EPA has periodically issued ambient water quality criteria.
    In July 1976, EPA published ``Quality Criteria for Water--1976'', 
which provided a freshwater aquatic life criteria for phthalate esters. 
A criterion value of 3 ug/L was established based on available acute 
and chronic data.
    Four years later, EPA published a notice of availability of 
``Ambient Water Quality Criteria for Phthalate Esters'' in the Federal 
Register, (45 FR 79318, November 28, 1980), (Ref. 2). This document 
established a Lowest Observed Effect Level (LOEL) of 3 ug/L for aquatic 
life, based on acute and chronic data. In addition this document 
greatly expanded the data base considered for this chemical.
    A draft aquatic life criteria document for DEHP was made available 
for public comment on May 14, 1990, (55 FR 1986). This draft proposed 
establishing a chronic criteria of 360 ug/L and an acute criteria of 
400 ug/L for both freshwater and saltwater. EPA is announcing the 
availability of an information document on aquatic life toxicity for 
Di-2-Ethylhexyl Phthalate for the protection of freshwater and 
saltwater aquatic organisms. This final document was derived after 
consideration of all comments received and following analysis of 
additional data received after the draft document was published in 
1990.

Summary of Information Document on Aquatic Life Toxicity for Di-2-
Ethylhexyl Phthalate

    The procedures described in the ``Guidelines for Deriving Numerical 
National Water Quality Criteria for the Protection of Aquatic Organisms 
and Their Uses'', (hereafter referred to as the Guidelines) do not 
allow for the derivation of national criteria for Di-2-Ethylhexyl 
Phthalate (DEHP), based on the available test information.
    Limited data indicate that acute toxicity occurs to freshwater 
aquatic life at a concentration as low as 2,000 ug/L, which is above 
the reported solubility limit for DEHP. Based on water solubility 
values which ranged from 270 ug/L to 400 ug/L, the mean concentration 
of 334 ug/L was calculated as the best estimate of water solubility for 
DEHP for this document. Chronic toxicity occurs to one freshwater 
species at a concentration as low as 160 ug/L, and would occur at lower 
concentrations among untested species that are more sensitive.
    DEHP toxicity data for saltwater aquatic life is limited. However, 
if the chronic sensitivity of saltwater aquatic life to DEHP is similar 
to that of freshwater aquatic life, adverse effects on individual 
species might be expected at  160 ug/L.
    Data on the acute toxicity of DEHP are available for fourteen 
species of freshwater animals and four saltwater organisms. In nearly 
all acute tests, the highest concentrations tested were not acutely 
toxic. Therefore, only ``greater-than'' the tested concentrations could 
be reported in this document. A final acute value for freshwater or 
saltwater organisms cannot be calculated because not enough definitive 
acute values exist to meet the minimum data base requirements according 
to the guidelines.
    No final value, as defined in the Guidelines, can be calculated for 
either freshwater or saltwater plants. There is no Food & Drug 
Administration (FDA) action level or an available maximum dietary 
intake value derived from a chronic feeding study or a long-term field 
study with wildlife.
    A final acute value cannot be calculated for DEHP, and only two 
acute-chronic ratios are available as greater-than values; therefore, 
no final chronic value for DEHP can be calculated using the final 
acute-chronic ratio procedure according to the Guidelines.

Response to Public Comments on the Information Document on Aquatic Life 
Toxicity for Di-2-Ethylhexyl Phthalate

    Comments to the draft criteria document were made by the following: 
Chemical Manufacturers Association (CMA), American Water Works 
Association (AWWA), Monsanto Company, State of Ohio Environmental 
Protection Agency, Dow Chemical USA, Detroit Water and Sewerage 
Department, State of Maryland Department of the Environment, Utility 
Act Group.
    The following are responses to comments by several organizations on 
the draft document for Di-2-Ethylhexyl Phthalate (DEHP), which was 
published in the Federal Register on May 14, 1990, (55 FR 11986, Docket 
No. OW-FRL-3762-9). The draft, dated 9/24/87, was revised by ERL-Duluth 
and ERL-Narragansett, based on these comments and additional literature 
information. EPA has chosen not to issue numerical national criteria 
for DEHP instead of the criteria initially proposed in the Federal 
Register draft, most of the comments are no longer issued. However, EPA 
has responded to each comment for the record.
    The following comments represent a summary of the most important 
comments received. The complete response to public comment document can 
be obtained by contacting the Office of Water Resource Center at the 
previously noted address.
    Commentor--EPA should withdraw the numerical Criteria Maximum 
Concentration (CMC) for DEHP and replace it with a narrative criterion 
of ``free from floating material''. The EPA should not publish the 
final aquatic life criteria values that are strictly based on 
solubility for DEHP. EPA should not use the solubility limit as a 
surrogate for a CMC. The approach of using solubility results is 
unnecessarily stringent criteria. The EPA should not set water quality 
criteria in situations where no toxicity has been observed. CMA 
recommends that EPA formally withdraw the 1980 phthalate esters 
criteria document with notice in the Federal Register to avoid 
confusion and misunderstanding that result from continued use of this 
document.
    Response--EPA agrees that the CMC for DEHP, as stated in the 9/24/
87 draft document, should not be used. EPA acknowledges the fact that a 
numerical CMC cannot be calculated for Di-2-Ethylhexyl Phthalate 
because not enough of the available acute toxicity test information 
provides definitive toxicity endpoints (i.e., LC50s) for calculating a 
Final Acute Value for either freshwater or saltwater organisms, 
according to the ``Guidelines for Deriving Numerical National Water 
Quality Criteria for the Protection of Aquatic Organisms and Their 
Uses'', hereafter referred to as the Guidelines. Several studies shows 
that DEHP is not toxic at the tested concentrations. This results in 
``greater than'' LC50's for most tests with freshwater organisms and 
for all tests with saltwater organisms. Most often, concentrations 
greatly exceed the water solubility limit of 334 ug/L; EPA's best 
estimate based on the current literature. Therefore, EPA will not issue 
a freshwater or saltwater CMC for DEHP based on the available acute 
test information. The information presented in this document will 
supersede previous national aquatic life water quality criteria for 
DEHP (U.S. EPA, 1976 1980 (Ref. I and 3 respectively).
    Commentor--The Criteria Continuous Concentration (CCC) for DEHP 
should be recalculated using data previously 

[[Page 49604]]
submitted to EPA by the CMA Phthalate Esters Panel as part of a 
voluntary testing program under Section 4 of TSCA. The CCC for DEHP 
should be established at 200 ug/L based on available chronic toxicity 
data although it is less rigorous than the EPA Guidelines approach. The 
current chronic guidance value for all phthalate esters should be 
publicly withdrawn immediately. EPA should calculate separate CMC's and 
CCC's for freshwater and saltwater organisms.
    Response--EPA acknowledges that not enough chronic toxicity tests 
are available to provide definitive endpoints for calculating the 
chronic values for DEHP. This lack of information combined with the 
lack of definitive acute information also does not allow for 
calculation of a Final Chronic Value, according to the Guidelines. 
Therefore, EPA will not issue a freshwater or saltwater CCC for DEHP 
based on the available chronic test information. However, one chronic 
toxicity test indicates that DEHP is toxic to Daphnia magna (a 
freshwater cladoceran) at concentrations below DEHP's water solubility 
limit of 334 ug/L. Data provided by CMA show that DEHP concentrations 
as low as 160 and 290 ug/L are chronically toxic to this species. These 
results conflict with those from other studies which indicate that DEHP 
is only toxic to this same species at concentrations above solubility 
(358 to 5,394 ug/L). Because of the large uncertainty associated with 
this range of results combined with limited definitive chronic data for 
DEHP, there is concern that this group of aquatic species could be 
affected unacceptably if populations are exposed for long periods of 
time to DEHP at concentrations  160 ug/L.
    EPA is not recommending any CCC for DEHP, CMA's recommendation of 
using 200 ug/L as the CCC for this chemical is no longer an issue. 
However, this value cannot be recommended as a ``level of concern'' 
because CMA's own data show that concentrations  160 ug/L 
are chronically toxic. In addition, it is possible that untested 
concentrations that are lower than 160 ug/L could be toxic to 
cladocerans since the chronic value calculated from CMA's study is 110 
ug/L, and effect concentrations could occur at still lower 
concentrations among untested freshwater species that are more 
sensitive than cladocerans.
    Toxicity data for DEHP and saltwater aquatic life is very limited. 
However, if their chronic sensitivity to DEHP is similar to that of 
freshwater aquatic life, adverse effects on individual species might be 
expected at  160 ug/L. An ecosystem process, ammonia flux, 
has been shown to be reduced at 15.5 ug/L during summer months.
    Commentor--Since human health and aquatic life criteria address 
different uses of a water body, EPA should view these criteria 
independently. Two separate criteria should be based on sound 
scientific studies which are available for public review and comment.
    Response--Information for deriving water quality criteria for the 
protection of human health and aquatic life are gathered independently 
of each other and are currently used separately for preparing 
individual criteria documents for human health and aquatic life 
protection. The 1987 draft document only included information on DEHP 
and aquatic life. In addition, the 1985 Guidelines do not involve human 
health concerns except for FDA action levels for fish oil or the edible 
portion of fish or shellfish. DEHP does not have a FDA action level at 
this time; therefore, aquatic life criteria cannot be influenced by 
residue that are used in connection with the protection of human 
health.
    Commentor--The draft document assumes that DEHP is equal in 
toxicity to freshwater and saltwater organisms. A minimum data set for 
saltwater species should be derived with which to calculate saltwater 
criteria. Water quality factors such as pH, hardness, alkalinity and 
temperature can play a major role in the toxicity of a constituent. 
Ideally, the water quality factors likely to impact the toxicity of a 
constituent should be determined and factored into the development of 
the Criteria Continuous Concentration (CCC) and the Criteria Maximum 
Concentration (CMC) numbers. If this is not performed, the states 
should be allowed flexibility to set water quality criteria based on 
both positive and negative influence from other water quality factors.
    Response--EPA agrees that there is not enough data to meet the 
minimum data base for deriving criteria for saltwater organisms and 
will not issue a saltwater criteria for DEHP. EPA agrees that water 
quality factors can play a major role in the toxicity of a chemical and 
already uses this type of information for deriving criteria, if it is 
available. Although more information is needed to discern correlations 
between the above stated factors and the toxicity of DEHP, the limited 
current information on this chemical does not indicate that such 
correlations exist.
    At the present time, states are allowed the flexibility to derive 
criteria with any data that are acceptable to the Guidelines and, in 
addition, are allowed to modify national criteria to site-specific 
criteria to better reflect local conditions including instances where 
the above factors may impact toxicity.
    Commentor--The latest comprehensive literature searches for 
information for the DEHP document was conducted four years ago. This 
information document, therefore, may already be out of date. More 
timely literature searches should be conducted for this an criteria 
documents.
    Response--EPA agrees that the literature search for this document 
is out of date and a new search was conducted in September of 1992. New 
information from this search has been added to the revised document.
    Commentor--Many different water solubilities for DEHP are given in 
the published literature. How did EPA arrive at 400 ug/L as the water 
solubility for DEHP?
    Response--Many values for DEHP water solubility are indicated in 
various published studies. However, only the values derived from 
studies specifically designed to measure water solubility were 
considered useable in the 1987 draft (270, 300, 340, 360 and 400 ug/L), 
and the highest value of 400 ug/L was chosen to provide the most 
liberal estimate of the amount of DEHP that would be possible in 
aqueous solution. However, EPA has now revised the estimate to be 334 
ug/L by using the mean concentration from the five values listed above.
    Commentor--The bioconcentration discussion in the document lacks 
information on the metabolism of DEHP by fish and reported BCF's are 
for total 14 C analyses, not DEHP.
    Response--Information now included in the revised draft document 
for DEHP shows that DEHP can be metabolized by fish (Barron et al., 
1989). The Bioconcentration Factors (BCF's) Environmental Protection 
Agency: AWOC for DEHP--Page 8 of 8 reported in Table 5 of this draft 
are based on measurements of 14 C in water and tissue and most 
likely include concentrations of both DEHP and stable metabolites. 
Consequently, these factors are probably overestimating the 
bioaccumulation potential of DEHP in the organisms shown in table 5 of 
the 1987 draft document. However, since the concentrations of actual 
DEHP relative to the concentrations of it's metabolites are not known 
for the organisms listed, the bioconcentration factor are EPA's best 
estimate of DEHP bioaccumulation. EPA also agrees that more information 
is needed to better estimate DEHP bioaccumulation in aquatic organisms. 
Since there is no FDA action limit or an available maximum dietary 
intake value 

[[Page 49605]]
derived from a chronic feeding study or a long-term field study with 
wildlife, a Final Residue Value (FRV) for DEHP cannot be calculated 
and, therefore, criteria based on a FRV cannot be derived at this time.

    Dated: September 13, 1995.
Tudor T. Davies,
Director, Office of Science and Technology.

References

    1. U.S. EPA; ``Quality Criteria for Water-1976''; EPA-440/9-76 
023; NTIS # PB 263-943. National Technical Information Service. 
Springfield, VA. pp.191-192.
    2. Federal Register notice November 28, 1980; 45 FR 79339.
    3. U.S. EPA; ``Ambient Water Quality Criteria for Phthalate 
Esters'' October 1980, EPA-440/5-80-067.
    4. U.S. EPA Draft ``Ambient Water Quality Criteria for Di-2-
Ethylhexy1 Phthalate''; September 24, 1987; 440/5-87-013.
    5. Stephen, C.E., D.I. Mount, D.J. Hansen, J.H. Gentile, G.A 
Chapman and W.A. Brungs. 1985; 822R85100. ``Guidelines for Deriving 
National Water Quality Criteria for the Protection of Aquatic 
organisms and Their Uses''. PB85-227049. National Technical 
Information Service Springfield, Va.
    6. Barron, M.G., I.R. Schultz and W.L. Hayton. 1989. Presystemic 
brachial metabolism limits Di-2-Ethylhexyl Phthalate accumulation in 
fish. Toxicol. Appl. Pharmacol 98:48-57.
[FR Doc. 95-23844 Filed 9-25-95; 8:45 am]
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