Phosmet (CASRN 732-11-6)
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0091
Phosmet; CASRN 732-11-6
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 Phosmet
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 — Phosmet
CASRN — 732-11-6
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 |
---|---|---|---|---|
Reduced body weight 2-Year Rat Feeding Stauffer Chemical, 1967 |
NOEL: 40 ppm LEL: 400 ppm |
100 |
1 |
2E-2 mg/kg/day |
*Dose Conversion Factors & Assumptions: 1 ppm = 0.05 mg/kg/day (assumed rat food consumption)
__I.A.2. Principal and Supporting Studies (Oral RfD)
Stauffer Chemical Company. 1967. MRID No. 00062651, 00075419, 00076436, 00080431, 00080556; HED Doc. No. 001999. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Phosmet was administered in the diet at levels of 20, 40, and 400 ppm to groups of 25 Charles River strain albino rats/sex for a period of 2 years. A control was included. There was slight decrease in body weight gain in males in the 400 ppm group. Plasma, erythrocyte, and brain cholinesterase activity was decreased in the 400 ppm group. Moderate liver cell vacuolation was observed in rats in the 400 ppm group.
__I.A.3. Uncertainty and Modifying Factors (Oral RfD)
UF — Based on a chronic exposure study, an uncertainty factor of 100 was used to account for inter- and intra- species differences.
MF — None
__I.A.4. Additional Studies/Comments (Oral RfD)
The NOEL in a 2-year dog study is 1 mg/kg/day, less than the NOEL used in support of the RfD. However, since systemic effects were noted in the rat, a l00 fold UF was applied to the rat NOEL (2.0 mg/kg/day) rather than a l0-fold UF applicable to the ChE inhibition observed in the dog. Thus, overall a more restrictive RfD value was calculated.
Data Considered for Establishing the RfD
1) 2-Year Feeding (Oncogenic) - rat: Systemic NOEL=40 ppm (2 mg/kg/day); ChE NOEL=40 ppm; LEL=400 ppm (20 mg/kg/day) (decreased body weight gain in males; increased incidence of moderate liver cell vacuolation; inhibition of plasma, erythrocyte and brain cholinesterase activity); core grade minimum (Stauffer Chemical Co., 1967)
2) 2-Year Feeding - dog: NOEL=40 ppm (1.0 mg/kg/day); LEL=400 ppm (10 mg/kg/day) (inhibition of erythrocyte and brain cholinesterase activity); core grade minimum (Stauffer Chemical Co., 1967)
3) 3-Generation Reproduction - rat: NOEL=80 ppm (4 mg/kg/day) (HDT); core grade minimum (Stauffer Chemical Co., 1968a)
4) Teratology - rabbit: Teratogenic and Reproductive NOEL=60 mg/kg (HDT) (cholinesterase activity inhibited from 10 mg/kg upwards); core grade minimum (Stauffer Chemical Co., 1966a)
5) Teratology - monkey: NOEL=8 mg/kg (HDT); core grade minimum (Stauffer Chemical Co., 1968b)
Data Gap(s): None
Other Data Reviewed
1) Teratology - rabbit: NOEL=35 mg/kg/day (HDT); core grade supplementary (Stauffer Chemical Co., 1966b)
2) Teratology - rat: NOEL=30 mg/kg/day (HDT) (reduced maternal body weight gain at 30 mg/kg/day); core grade supplementary (Stauffer Chemical Co., 1979)
3) Teratology - rat: NOEL=25 mg/kg/day (gavage) and 29 mg/kg/day (diet); core grade supplementary (Stauffer Chemical Co., 1976)
__I.A.5. Confidence in the Oral RfD
Study — High
Database — High
RfD — High
The principal study appears to be of good quality and is given a high confidence rating. Additional studies are of good quality; therefore, the database is given a high confidence rating. High confidence in the RfD follows.
__I.A.6. EPA Documentation and Review of the Oral RfD
Pesticide Registration Standard, April 1986
Pesticide Registration Files
Agency Work Group Review — 06/10/1986
Verification Date — 06/10/1986
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 Phosmet conducted in September 2002 identified one or more significant new studies. IRIS users may request the references for those studies from 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 — Phosmet
CASRN — 732-11-6
Not available at this time.
_II. Carcinogenicity Assessment for Lifetime Exposure
Substance Name — Phosmet
CASRN — 732-11-6
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 — Phosmet
CASRN — 732-11-6
Last Revised — 01/01/1992
_VI.A. Oral RfD References
Stauffer Chemical Company. 1966a. MRID No. 00062649, 00080433, 0009076; HED Doc. No. 001999. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Stauffer Chemical Company. 1966b. MRID No. 00062649; HED Doc. No. 001999. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Stauffer Chemical Company. 1967. MRID No. 00062651, 00075419, 00076436, 00080431, 00080556; HED Doc. No. 001999. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Stauffer Chemical Company. 1968a. MRID No. 00062650, 00081432; HED Doc. No. 001999. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Stauffer Chemical Company. 1968b. MRID No. 00112269; HED Doc. No. 001999. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Stauffer Chemical Company. 1976. MRID No. 00063192; HED Doc. No. 005102. Available from EPA. Write to FOI, EPA, Washington, DC 20460.
Stauffer Chemical Company. 1979. MRID No. 00031555; HED Doc. No. 001999. 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 — Phosmet
CASRN — 732-11-6
Date |
Section |
Description |
---|---|---|
03/31/1987 | IV. | Regulatory Action section on-line |
01/01/1992 | I.A.4. | Citations added |
01/01/1992 | IV. | Regulatory actions updated |
01/01/1992 | VI. | Bibliography 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. |
_VIII. Synonyms
Substance Name — Phosmet
CASRN — 732-11-6
Last Revised — 01/31/1987
- 732-11-6
- APPA
- DECEMTHION
- DECEMTHION P-6
- ENT 25,705
- FTALOPHOS
- IMIDAN
- KEMOLATE
- N-(MERCAPTOMETHYL)PHTHALIMIDE S-(O,O-DIMETHYL PHOSPHORODITHIOATE)
- O,O-DIMETHYL-PHTHALIMIDIOMETHYL-DITHIOPHOSPHATE
- O,O-DIMETHYL 5-(PHTHALIMIDOMETHYL)DITHIOPHOSPHATE
- O,O-DIMETHYL S-(N-PHTHALIMIDOMETHYL) DITHIOPHOSPHATE
- O,O-DIMETHYL S-PHTHALIMIDOMETHYL PHOSPHORODITHIOATE
- PERCOLATE
- Phosmet
- PHOSPHORODITHIOIC ACID, S-((1,3-DIHYDRO-1,3-DIOXO-ISOINDOL-2-YL)METHYL) O,O- DIMETHYL ESTER
- PHTHALIMIDOMETHYL O,O-DIMETHYL PHOSPHORODITHIOATE
- PHTHALIMIDO O,O-DIMETHYL PHOSPHORODITHIOATE
- PHTHALOPHOS
- PMP
- PROLATE
- R 1504
- SMIDAN
- STAUFFER R 1504