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Dimethyl terephthalate (DMT)
CASRN 120-61-6
Contents
0046
Dimethyl terephthalate (DMT); CASRN 120-61-6
Health assessment information on a chemical substance is included in IRIS only
after a comprehensive review of chronic toxicity data by U.S. EPA health
scientists from several Program Offices and the Office of Research and
Development. The summaries presented in Sections I and II represent a
consensus reached in the review process. Background information and
explanations of the methods used to derive the values given in IRIS are
provided in the Background Documents.
STATUS OF DATA FOR DMT
File On-Line 01/31/1987
Category (section) Status Last Revised
----------------------------------------- -------- ------------
Oral RfD Assessment (I.A.) on-line 02/01/1995
Inhalation RfC Assessment (I.B.) no data
Carcinogenicity Assessment (II.) no data
_I. CHRONIC HEALTH HAZARD ASSESSMENTS FOR NONCARCINOGENIC EFFECTS
__I.A. REFERENCE DOSE FOR CHRONIC ORAL EXPOSURE (RfD)
Substance Name -- Dimethyl terephthalate (DMT)
CASRN -- 120-61-6
Last Revised -- 02/01/1995
The oral Reference Dose (RfD) is based on the assumption that thresholds exist
for certain toxic effects such as cellular necrosis. It is expressed in units
of mg/kg-day. In general, the RfD is an estimate (with uncertainty spanning
perhaps an order of magnitude) of a daily exposure to the human population
(including sensitive subgroups) that is likely to be without an appreciable
risk of deleterious effects during a lifetime. Please refer to the Background
Document for an elaboration of these concepts. RfDs can also be derived for
the noncarcinogenic health effects of substances that are also carcinogens.
Therefore, it is essential to refer to other sources of information concerning
the carcinogenicity of this substance. If the U.S. EPA has evaluated this
substance for potential human carcinogenicity, a summary of that evaluation
will be contained in Section II of this file.
___I.A.1. ORAL RfD SUMMARY
Critical Effect Experimental Doses* UF MF RfD
-------------------- ----------------------- ----- --- ---------
Chronic kidney in- NOEL: none 1000 1 1E-1
flammation mg/kg/day
LOAEL: 2500 ppm of
Rat Chronic Dietary diet (125 mg/kg
Study bw/day)
NCI, 1979
*Conversion Factors: Rat food consumption assumed to be 5% of bw/day
___I.A.2. PRINCIPAL AND SUPPORTING STUDIES (ORAL RfD)
NCI (National Cancer Institute). 1979. Bioassay of dimethyl terephthalate
for possible carcinogenicity. DHEW/PUB/NIH 79-1376, NCI-CG-TR121.
In the NCI (1979) study mice and rats (50/sex/group) were fed dimethyl
terephthalate (DMT) at levels of 0, 2500, and 5000 ppm (diet) for 103 weeks.
A small but dose-related increase in the incidence of chronic kidney
inflammation was shown for male mice and female rats; the incidence for male
mice was 2/49, 4/49, and 11/49, and for female rats was 3/49, 5/49, and 8/49
for the control, low-dose and high-dose groups, respectively. Statistics were
not given. Subchronic preliminary studies showed mild liver effects but no
indication of kidney toxicity. The rat LOAEL is used since it is lower in
mg/kg bw/day than the mouse LOAEL (125 vs. 325 mg/kg/day, respectively).
Krasavage et al. (1973) reported a statistically significant decrease in body
weight gain for male Long-Evans rats fed DMT at about 1000 mg/kg/day for 96
days. Dose levels of 250 and 500 mg/kg/day DMT reduced body weight gain
slightly, but the reductions were not statistically significant. Hematologic,
clinical chemistry, liver and kidney weight, and histopathologic parameters
were similar in treated and control animals. Krasavage et al. (1973) also
reported significantly reduced weight of offspring at weaning for rats fed DMT
at 500 and 1000 mg/kg bw/day for 2-3 months. No effects were observed at 250
mg/kg bw/day.
Short-term studies in rats have shown that levels of about 500-1000 mg/kg/day
DMT are associated with urinary acidosis and attendant calciuria. DMT at 1500
mg/kg/day is associated with the induction of bladder stones. No other
information on the chronic toxicity of DMT was found.
The interpretation of the NCI (1979) data as evidence of dose-related effects
for kidney inflammation is weakened by the low number of doses and magnitude
of response and the lack of statistical support. However, the effect is
observed in two species, and short-term studies show urinary tract effects at
higher doses.
___I.A.3. UNCERTAINTY AND MODIFYING FACTORS (ORAL RfD)
UF -- The UF of 1000 includes uncertainties in the following areas:
extrapolation of experimental animal data to man, the range of human
sensitivity, and extrapolation from a LOAEL to a hypothetical NOEL.
MF -- None
___I.A.4. ADDITIONAL COMMENTS (ORAL RfD)
Data adequately assessing the teratogenic potential of DMT are not found.
___I.A.5. CONFIDENCE IN THE ORAL RfD
Study -- Medium
Data Base -- Low
RfD -- Low
The medium confidence level assigned to the principal study reflects both the
strengths (large number of animals, extensive histopathology, length of study)
and the weaknesses (lack of other toxicologic parameters, limited dose range)
inherent to a study primarily designed to assess carcinogenic potential. The
data base is rated low because of the general lack of supporting data and the
absence of a NOAEL. Overall confidence in the RfD is low.
___I.A.6. EPA DOCUMENTATION AND REVIEW OF THE ORAL RfD
Source Document -- U.S. EPA, 1984
The ADI in the 1984 Health and Environmental Effects Profile has received an
Agency review with the help of two external scientists.
Other EPA Documentation -- None
Agency Work Group Review -- 10/09/1985
Verification Date -- 10/09/1985
___I.A.7. EPA CONTACTS (ORAL RfD)
Please contact the Risk Information Hotline for all questions concerning this
assessment or IRIS, in general, at (513)569-7254 (phone), (513)569-7159 (FAX)
or RIH.IRIS@EPAMAIL.EPA.GOV (internet address).
__I.B. REFERENCE CONCENTRATION FOR CHRONIC INHALATION EXPOSURE (RfC)
Substance Name -- Dimethyl terephthalate (DMT)
CASRN -- 120-61-6
Not available at this time.
_II. CARCINOGENICITY ASSESSMENT FOR LIFETIME EXPOSURE
Substance Name -- Dimethyl terephthalate (DMT)
CASRN -- 120-61-6
This substance/agent has not undergone a complete evaluation and determination
under US EPA's IRIS program for evidence of human carcinogenic potential.
_VI. BIBLIOGRAPHY
Substance Name -- Dimethyl terephthalate (DMT)
CASRN -- 120-61-6
Last Revised -- 08/01/1989
__VI.A. ORAL RfD REFERENCES
Krasavage, W.J., F.J. Yanno and C.J. Terhaar. 1973. Dimethyl terephthalate
(DMT). Acute toxicity subacute. Feeding inhalation studies in male rats. Am.
Ind. Hyg. Assoc. J. 34(10): 455-462.
NCI (National Cancer Institute). 1979. Bioassay of Dimethyl Terephthalate
for Possible Carcinogenicity. DHEW/PUB/NIH 79-1376, NCI-CG-TR121.
U.S. EPA. 1984. Health and Environmental Effects Profile for Dimethyl
Terephthalate. Prepared by the Office of Health and Environmental Assessment,
Environmental Criteria and Assessment Office, Cincinnati, OH for the Office of
Solid Waste, Washington, DC.
__VI.B. INHALATION RfC REFERENCES
None
__VI.C. CARCINOGENICITY ASSESSMENT REFERENCES
None
_VII. REVISION HISTORY
Substance Name -- Dimethyl terephthalate (DMT)
CASRN -- 120-61-6
-------- -------- --------------------------------------------------------
Date Section Description
-------- -------- --------------------------------------------------------
03/01/1988 I.A.5. Confidence levels revised
08/01/1989 VI. Bibliography on-line
01/01/1992 I.A.7. Secondary contact changed
01/01/1992 IV. Regulatory Action section on-line
02/01/1995 I.A.7. Secondary contact's name changed
VIII. SYNONYMS
Substance Name -- Dimethyl terephthalate (DMT)
CASRN -- 120-61-6
Last Revised -- 01/31/1987
120-61-6
1,4-BENZENEDICARBOXYLIC ACID, DIMETHYL ESTER
DIMETHYL 1,4-BENZENEDICARBOXYLATE
DIMETHYLESTER KYSELINY ISOFTALOVE
DIMETHYL p-PHTHALATE
Dimethyl Terephthalate
DMT
METHYL 4-CARBOMETHOXYBENZOATE
NCI-C50055
TEREPHTHALIC ACID, DIMETHYL ESTER
TEREPHTHALIC ACID METHYL ESTER
Last updated: 5 May 1998
URL: http://www.epa.gov/iris/SUBST/0046.HTM
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