Propachlor (CASRN 1918-16-7)
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0096
Propachlor; CASRN 1918-16-7
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 Propachlor
File First On-Line 01/31/1987
Category (section) |
Status |
Last Revised |
---|---|---|
Oral RfD Assessment (I.A.) | on-line | 01/01/1992 |
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 — Propachlor
CASRN — 1918-16-7
Last Revised — 01/01/1992
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 |
---|---|---|---|---|
Decreased weight 90-Day Feeding Study Monsanto Co., 1964a |
NOEL: 13.3 mg/kg/day LEL: 133.3 mg/kg/day |
1000 |
1 |
1.3E-2 mg/kg/day |
*Conversion Factors: Study conducted with 65% wettable powder.
__I.A.2. Principal and Supporting Studies (Oral RfD)
Monsanto Company. 1964a. MRID No. 00093270; HED Doc. No. 001381. Available from EPA. Write to FOI, EPA, Washington DC 20460.
Twenty-five rats/sex/dose were fed concentrations of propachlor (as 65% wettable powder) in the diet that were calculated to equal 0, 1.3, 13.3, and 133.3 mg/kg/day. Dietary concentrations were adjusted weekly so as to maintain the desired dosages. The effects of treatment on body weight gain, food consumption, hematology, urinalysis, and gross and microscopic pathology were assessed. The only apparent effects of treatment were decreases in body weights in males and females of 10-12%, and increases in relative liver weights of about 10%.
__I.A.3. Uncertainty and Modifying Factors (Oral RfD)
UF — Based on a subchronic exposure study, an uncertainty factor of 1000 was used to account for inter- and intraspecies differences, and the insufficient duration of the study to fully assess chronic effects.
MF — None
__I.A.4. Additional Studies/Comments (Oral RfD)
Data Considered for Establishing the RfD
1) 90-Day Feeding - rat: Principal study - see discussion above; no core grade
2) 90-Day Feeding - dog: NOEL=133.3 mg/kg/day (HDT); no core grade (Monsanto Co., 1964b)
3) Teratology - rat: Maternal and Development NOEL=200 mg/kg/day, (HDT); core grade minimum (Monsanto Co., 1982)
Other Data Reviewed
1) Teratology - rabbit: Study under review.
2) 90-Day Feeding - rat: Study under review.
3) 90-Day Feeding - rat: Study under review.
Data Gap(s): Chronic Rat Feeding Study; Chronic Dog Feeding Study; Rat Reproduction Study
__I.A.5. Confidence in the Oral RfD
Study — Low
Database — Low
RfD — Low
The principal study appears to be of low quality and is given a low confidence rating. Since data gaps exist, the database is given a low confidence rating. Low confidence in the RfD follows.
__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 — Pesticide Registration Standard, August 1984; Pesticide Registration Files
Agency Work Group Review — 07/22/1986
Verification Date — 07/22/1986
__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 — Propachlor
CASRN — 1918-16-7
Not available at this time.
_II. Carcinogenicity Assessment for Lifetime Exposure
Substance Name — Propachlor
CASRN — 1918-16-7
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 — Propachlor
CASRN — 1918-16-7
Last Revised — 07/01/1992
_VI.A. Oral RfD References
Monsanto Company. 1964a. MRID No. 00093270; HED Doc. No. 001381. Available from EPA. Write to FOI, EPA, Washington DC 20460.
Monsanto Company. 1964b. MRID No. 00093270; HED Doc. No. 001381, 003921. Available from EPA. Write to FOI, EPA, Washington DC 20460.
Monsanto Company. 1982. MRID No. 001151136; HED Doc. No. 002402. Available from EPA. Write to FOI, EPA, Washington DC 20460.
_VI.B. Inhalation RfC References
None
_VI.C. Carcinogenicity Assessment References
None
_VII. Revision History
Substance Name — Propachlor
CASRN — 1918-16-7
Date |
Section |
Description |
---|---|---|
03/31/1987 | IV. | Regulatory Action section on-line |
01/01/1992 | I.A.4. | Citations added |
01/01/1992 | VI. | Bibliography on-line |
01/01/1992 | IV. | Regulatory actions updated |
07/01/1992 | III.A. | Health Advisory on-line |
07/01/1992 | VI.D. | Health Advisory references 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. |
01/09/2002 | I.A., II. | This chemical is being reassessed under the IRIS Program. |
02/09/2004 | I.A., II. | This chemical is no longer being reassessed under the IRIS Program. See Federal Register February 9, 2004 (Volume 69, Number 26). |
_VIII. Synonyms
Substance Name — Propachlor
CASRN — 1918-16-7
Last Revised — 01/31/1987
- 1918-16-7
- ACETAMIDE, 2-CHLORO-N-(1-METHYLETHYL)-N-PHENYL-
- ACETANILIDE, 2-CHLORO-N-ISOPROPYL-
- BEXTON
- BEXTON 4L
- CHLORESSIGSAEURE-N-ISOPROPYLANILID
- 2-CHLORO-N-ISOPROPYLACETANILIDE
- alpha-CHLORO-N-ISOPROPYLACETANILIDE
- 2-CHLORO-N-ISOPROPYL-N-PHENYLACETAMIDE
- CP 31393
- N-ISOPROPYL-2-CHLOROACETANILIDE
- N-ISOPROPYL-alpha-CHLOROACETANILIDE
- NITICID
- Propachlor
- PROPACHLORE
- RAMROD
- RAMROD 65
- SATECID