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Phosphorothioic acid, O,O-dimethyl O-(2-(ethylthio)ethyl) ester, mixed with O,O-dimethyl S-(2-(ethylthio)ethyl) ester (7:3)

RTECS #
TG1760000
CAS #
8022-00-2
See: NMAM or OSHA Methods
Updated
September 2013
Molecular Weight
230.30
Molecular Formula
C6H15O3PS2
Synonyms
Bayer 21/116
Demeton methyl
Duratox
Metasystox
Methyl demeton
Methyl demeton (ACGIH)
Methyl systox
Methyl-mercaptophos
Methylmerkaptofos (Czech)
S(and O)-2-(Ethylthio)ethyl O,O-dimethyl phosphorothioate

Reproductive Effects Data and References

Route/OrganismDoseEffectReference
inhalation/rat 200 ng/m3/24H (1-22D pregnant)Reproductive: Effects on embryo or fetus: Fetotoxicity (except death, e.g., stunted fetus)

Reproductive: Other developmental abnormalities

Reproductive: Specific developmental abnormalities: Musculoskeletal system
HYSAAV 36(1),34,1971
inhalation/rat 700 ng/m3/24H (1-22D pregnant)Reproductive: Effects on fertility: Pre- implantation mortality (e.g., reduction in number of implants per female; total number of implants per corpora lutea)HYSAAV 36(1),34,1971
inhalation/rat 100 µg/m3/24H (1-22D pregnant)Reproductive: Effects on fertility: Litter size (e.g., # fetuses per litter; measured before birth)HYSAAV 36(1),34,1971
inhalation/rat 500 µg/m3/24H (1-22D pregnant)Reproductive: Specific developmental abnormalities: Central nervous system

Reproductive: Effects on newborn: Sex ratio
HYSAAV 36(1),34,1971

Acute Toxicity Data and References

Route/OrganismDoseEffectReference
inhalation/cat Lowest published lethal concentration: 20 mg/m3/4H85GMAT -,85,1982
intravenous/rat lethal dose (50 percent kill): 12 mg/kgBJIMAG 15,158,1958
oral/cat lowest published lethal dose: 30 mg/kg85GMAT -,85,1982
oral/mouse lethal dose (50 percent kill): 26 mg/kg85JDAH -,197,1974
oral/rabbit lethal dose (50 percent kill): 46 mg/kgGISAAA 27(8),97,1962
oral/rat lethal dose (50 percent kill): 75 mg/kgFATOAO 22,259,1959
skin/rabbit lowest published lethal dose: 75 mg/kgGTPZAB 2(5),7,1958
skin/rat lethal dose (50 percent kill): 300 mg/kgWRPCA2 9,119,1970
unreported route/mammal (species unspecified) lethal dose (50 percent kill): 80 mg/kg30ZDA9 -,346,1971
unreported route/mouse lethal dose (50 percent kill): 3500 µg/kgBiochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesterasePCJOAU 3,508,1969

Other Multiple Dose Data and References

Route/OrganismDoseEffectReference
oral/cat lowest published toxic dose: 470 mg/kg/94D- intermittentBlood: Changes in serum composition (e.g. TP, bilirubin, cholesterol)

Biochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesterase

Related to Chronic Data: Death in the "MULTIPLE DOSE" data type field
FATOAO 22,559,1959
oral/rat lowest published toxic dose: 404 mg/kg/78W- intermittentBrain and Coverings: Other degenerative changes

Liver: Other changes

Biochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesterase
FATOBP 8,122,1973
oral/rat lowest published toxic dose: 1230 mg/kg/18W- intermittentBlood: Changes in serum composition (e.g. TP, bilirubin, cholesterol)

Biochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesterase

Related to Chronic Data: Death in the "MULTIPLE DOSE" data type field
FATOAO 22,559,1959

Reviews

OrganizationStandardReference
American Conference of Governmental Industrial Hygienists (ACGIH)Threshold Limit Value-time-weighted average 0.05 mg/m3 (inhal, vapor, skin)DTLVS* TLV/BEI,2013

Standards and Regulations

OrganizationStandardReference
Mine Safety and Health Administration (MSHA) STANDARD-airtime-weighted average 0.5 mg/m3 (skin)DTLVS* 3,165,1971
Occupational Exposure Limit IN ARGENTINA, BULGARIA, COLOMBIA, JORDAN check ACGIH TLV;
Occupational Exposure Limit IN SINGAPORE, VIETNAM check ACGIH TLV
Occupational Exposure Limit-AUSTRALIAtime-weighted average 0.5 mg/m3, JUL2008
Occupational Exposure Limit-AUSTRIAMAK-TMW 0.05 ppm (0.5 mg/m3);KZW 0.5 ppm (5 mg/m3), skin, 2007
Occupational Exposure Limit-BELGIUMtime-weighted average 0.5 mg/m3, Skin, MAR2002
Occupational Exposure Limit-DENMARKtime-weighted average 0.05 ppm (0.5 mg/m3), skin, MAY2011
Occupational Exposure Limit-FRANCEVME 0.5 mg/m3, Skin, FEB2006
Occupational Exposure Limit-GERMANYMAK 0.5 ppm (4.8 mg/m3), 2011
Occupational Exposure Limit-ICELANDtime-weighted average 0.05 ppm (0.5 mg/m3), skin, NOV2011
Occupational Exposure Limit-KOREAtime-weighted average 0.5 mg/m3, skin, 2006
Occupational Exposure Limit-MEXICOtime-weighted average 0.5 mg/m3;short term exposure limit 1.5 mg/m3 (skin), 2004
Occupational Exposure Limit-NEW ZEALANDtime-weighted average 0.5 mg/m3, skin, JAN2002
Occupational Exposure Limit-PERUtime-weighted average 0,5 mg/m3, JUL2005
Occupational Exposure Limit-RUSSIAshort term exposure limit 0.1 mg/m3, Skin, JUN2003
Occupational Exposure Limit-SWITZERLANDMAK-week 0.05 ppm (0.5 mg/m3), skin, JAN2011
Occupational Exposure Limit-THE NETHERLANDSMAC-TGG 0.5 mg/m3, Skin, 2003

NIOSH Documentation and Surveillance

OrganizationStandardReference
National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Level TO METHYL DEMETON-air10H time-weighted average 0.5 mg/m3 (Sk)NIOSH* DHHS #92-100,1992
National Occupational Hazard Survey 1974Hazard Code 26540; Number of Industries 1; Total Number of Facilities 165; Number of Occupations 2; Total Number of Employees Exposed 331
Page last reviewed: November 16, 2018