[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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