trans-1,2-Dichloroethylene (CASRN 156-60-5)
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trans-1,2-Dichloroethylene; CASRN 156-60-5
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 trans-1,2-Dichloroethylene
File First On-Line 09/26/1988
Category (section) |
Status |
Last Revised |
---|---|---|
Oral RfD Assessment (I.A.) | on-line | 01/01/1989 |
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 — trans-1,2-Dichloroethylene
CASRN — 156-60-5
Last Revised — 01/01/1989
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 |
---|---|---|---|---|
Increased serum 90-Day Mouse Drinking Barnes et al., 1985 |
NOAEL: 0.1 mg/L LOAEL: 1 mg/L |
1000
|
1
|
2E-2
mg/kg/day |
*Conversion Factors: See text.
__I.A.2. Principal and Supporting Studies (Oral RfD)
Barnes, D.W., V.M. Sanders, K.L. White, Jr., et al. 1985. Toxicology of trans-1,2-dichloroethylene in the mouse. Drug Chem. Toxicol. 8: 373-392.
Male and female CD-1 mice were given trans-1,2-dichloroethylene (DCE) in their drinking water for 90 days at concentrations of 0.1, 1.0, or 2.0 mg/mL. Based on fluid consumption, the doses were: males - 17, 175, or 387 mg/kg/day and females - 23, 224, or 452 mg/kg/day. There were no differences in fluid consumption among the various groups of mice and at the termination of the 90- day experiment, no DCE-induced changes in terminal body weight or gross pathology were noted in either sex at any dose level. In male mice (N=24), there were significant increases in serum alkaline phosphatase levels at the 175 and 387 mg/kg/day levels. In addition, liver glutathione concentrations were decreased at the highest dose. In females (N=24), the thymus weight, calculated as percent body weight, was significantly decreased at either 224 or 452 mg/kg/day, while the lung weight was depressed at the highest dose only. The levels of serum glutamic-pyruvic (SGPT) and glutamic-oxaloacetic (SGOT) transaminases were decreased at the two higher doses. In addition, the levels of aniline hydroxylase were decreased at all three dose levels, but the levels of cytochromes P-450 and b5, microsomal protein and aminopyrine N- demethylase were not affected by any dose of DCE. Since there is uncertainty about the toxicological significance of the decreases in SGOT, SGPT, and aniline hydroxylase, these parameters will not be used to set RfD values.
The immunotoxicity of trans-1,2-dichloroethylene (DCE) was assessed in a 90- day study by Shopp et al. (1985). Humoral immune status was assessed by measuring: 1) quantitation of spleen IgM antibody forming cells (AFC), 2) hemagglutination titers to sheep erythrocytes (sRBC), and 3) spleen response to the B cell mutagen lipopolysaccharide (LPS). Cell-mediated immunity was assayed by: 1) delayed type hypersensitivity (DTH) to SRBC, 2) popiteal lymph node proliferation in response to SRBC, and 3) spleen cell response to challenge with concanavalin A. In males on day 4 after treatment, there was a significant decrease in AFC/spleen at 17, 175, and 387 mg/kg/day does levels, but the decreases were only significant at the 175 and 387 mg/kg/day levels when the data were calculated on the basis of spleen cells. On day 5, a decrease in AFC was noted only at the 387 mg/kg/day level. No dose-dependent effects were noted in the DCE-treated female mice. In both sexes, there were no changes in hemagglutination titers after DCE treatment and spleen responsiveness to LPS was unaltered in male mice. However, females exposed to 452 mg/kg/day did have an enhanced response to LPS. In addition, lymphocyte responsiveness in the absence of the mitogen (LPS) was decreased at the 224 and 452 mg/kg/day doses in females only. In the cell-mediated immunity assays, there were no dose-related decreases seen in either sex. The significance of the decrease in AFC/spleen in male mice at all three dose levels is uncertain. This decrease is seen at only the 175 and 387 mg/kg/day levels when the data were calculated on the basis of spleen cells. Furthermore, two other measures of humoral immune status, hemagglutination titers and spleen cell response to LPS, were not affected. Accordingly, this parameter will not be used to set a RfD, but will be used as supportive data.
__I.A.3. Uncertainty and Modifying Factors (Oral RfD)
UF — The UF of 1000 allows for uncertainty in the extrapolation of dose levels from laboratory animals to humans (10A), uncertainty in the threshold for sensitive humans (10H), and uncertainty in the effect of duration when extrapolating from subchronic to chronic exposure (10S).
MF — None
__I.A.4. Additional Studies/Comments (Oral RfD)
CD rats, 22 to 30 days old, were given trans-1,2-dichloroethylene (DCE) for 90 days in their drinking water at doses of 402, 1311 or 3114 mg/kg/day for males and 353, 1257 or 2809 mg/kg/day for females (Hayes et al., 1987). The authors found no compound-related effects on fluid consumption, body weights, hematology, serum chemistry or urinalyses. They did note a significant dose- dependent decrease in kidney weight at the 1257 and 2809 mg/kg/day doses in female rats.
Wistar rats were exposed to air containing trans-1,2-dichloroethylene at 0, 200, 1000 or 2000 ppm (0 to 7940 mg/cu.m) (Freundt et al., 1977). Brief (8- hour) or prolonged (8 hours/day, 5 days/week for 1, 2, 8, or 16 weeks) exposure at 200 ppm produced slight degeneration of the liver lobule and lipid accumulation in the Kupffer cells. At 8 and 16 weeks of exposure, severe pneumonic infiltration was observed. Exposure at 1000 ppm for 8 hours resulted in significant reductions in serum albumin, urea nitrogen and alkaline phosphatase. Eight-hour exposures at both 200 and 1000 ppm produced a significant decrease in the number of leucocytes.
__I.A.5. Confidence in the Oral RfD
Study — Medium
Database — Low
RfD — Low
The principal study was well-designed, except for dose spacing, and did establish both a NOEL and LOAEL. The database confidence is rated low because of the lack of chronic studies and the lack of data on reproductive and developmental toxicity. Confidence in the RfD is rated low because of the database weakness.
__I.A.6. EPA Documentation and Review of the Oral RfD
Source Document — This assessment is not presented in any existing U.S. EPA document.
Other EPA Documentation — None
Agency Work Group Review — 04/20/1988
Verification Date — 04/20/1988
Screening-Level Literature Review Findings — A screening-level review conducted by an EPA contractor of the more recent toxicology literature pertinent to the RfD for trans-1,2-Dichloroethylene conducted in September 2002 did not identify any critical new studies. IRIS users who know of important new studies may provide that information to the IRIS Hotline at hotline.iris@epa.gov or (202)566-1676.
__I.A.7. EPA Contacts (Oral RfD)
Please contact the IRIS Hotline for all questions concerning this assessment or IRIS, in general, at (202)566-1676 (phone), (202)566-1749 (FAX) or hotline.iris@epa.gov (internet address).
_I.B. Reference Concentration for Chronic Inhalation Exposure (RfC)
Substance Name — trans-1,2-Dichloroethylene
CASRN — 156-60-5
Not available at this time.
_II. Carcinogenicity Assessment for Lifetime Exposure
Substance Name — trans-1,2-Dichloroethylene
CASRN — 156-60-5
This substance/agent has not undergone a complete evaluation and determination under US EPA's IRIS program for evidence of human carcinogenic potential.
_III.
[reserved]
_IV. [reserved]
_V. [reserved]
_VI. Bibliography
Substance Name — trans-1,2-Dichloroethylene
CASRN — 156-60-5
Last Revised — 03/01/1991
_VI.A. Oral RfD References
Barnes, D.W., V.M. Sanders, K.L. White, Jr., G.M. Shopp and A.E. Munson. 1985. Toxicology of trans-1,2-dichloroethylene in the mouse. Drug Chem. Toxicol. 8: 373-392.
Freundt, J.J., G.P. Liebaldt and E. Lieberwirth. 1977. Toxicity studies on trans-1,2-dichloroethylene. Toxicology. 7: 141-153.
Hayes, J.R., L.W. Condie, J.L. Egle and J.F. Borzelleca. 1987. The acute and subacute toxicity in rats of trans-1,2-dichloroethylene in drinking water. J. Amer. College Toxicol. 6(4): 471-478.
Shopp, G.M., V.M. Sanders, K.L. White and A.E. Munson. 1985. Humoral and cell-mediated immune status of mice exposed to trans-1,2-dichloroethylene. Drug Food Chem. Toxicol. 8(5): 393-407.
_VI.B. Inhalation RfC References
None
_VI.C. Carcinogenicity Assessment References
None
_VII. Revision History
Substance Name — trans-1,2-Dichloroethylene
CASRN — 156-60-5
Date |
Section |
Description |
---|---|---|
09/26/1988 | I.A. | Oral RfD summary on-line |
01/01/1989 | I.A.7. | Contact phone number corrected |
03/01/1991 | VI. | Bibliography on-line |
01/01/1992 | IV. | Regulatory Action section on-line |
04/01/1997 | III., IV., V. | Drinking Water Health Advisories, EPA Regulatory Actions, and Supplementary Data were removed from IRIS on or before April 1997. IRIS users were directed to the appropriate EPA Program Offices for this information. |
12/03/2002 | I.A.6. | Screening-Level Literature Review Findings message has been added. |
02/09/2004 | I., II. | This chemical is being reassessed under the IRIS Program. |
_VIII. Synonyms
Substance Name — trans-1,2-Dichloroethylene
CASRN — 156-60-5
Last Revised — 09/26/1988
- 156-60-5
- acetylene dichloride, trans-
- dichloroethylene, trans-
- 1,2-Dichloroethylene, trans-
- ethylene, 1,2-dichloro-, (E)-
- RCRA waste number U079
- trans-acetylene dichloride
- trans-dichloroethylene
- trans-1,2-Dichloroethylene