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

RTECS #
TF3150000
CAS #
8065-48-3; 8000-97-3; 8058-73-9
See: NMAM or OSHA Methods
Updated
September 2013
Molecular Weight
516.72
Molecular Formula
C8H19O3PS2·C8H19O3PS2
Synonyms
Bayer 8169
Demeton
Demeton (ACGIH:OSHA)
Diethoxy thiophosphoric acid ester of 2-ethylmercaptoethanol
E 1059
ENT 17,295
Ethyl systox
Mercaptofos
Mercaptophos
O,O-Diethyl 2-ethylmercaptoethyl thiophosphate
O,O-Diethyl O(and S)-2-(ethylthio)ethyl phosphorothioate mixture
Septox
Systox
Systox (OSHA)

Mutation Data and Reference

System TestRoute/Organism/TissueDoseReference
gene conversion and mitotic recombination/Saccharomyes cerevisiae500 ppmNTIS** PB84-138973
mutation in mammalian somatic cellslymphocyte/mouse80 mg/LNTIS** PB84-138973
mutation in microorganisms/Saccharomyes cerevisiae500 ppm (+/-enzymatic activation step)NTIS** PB84-138973
sister chromatid exchangeovary/hamster25 ppmNTIS** PB84-138973
sister chromatid exchangelung/hamster10 mg/LMUREAV 88,307,1981

Reproductive Effects Data and References

Route/OrganismDoseEffectReference
intraperitoneal/mouse 10 mg/kg (11D pregnant)Reproductive: Specific developmental abnormalities: Musculoskeletal system

Reproductive: Specific developmental abnormalities: Gastrointestinal system

Reproductive: Effects on embryo or fetus: Fetotoxicity (except death, e.g., stunted fetus)
TXAPA9 24,324,1973
parenteral/mouse 10 mg/kg (7D pregnant)Reproductive: Specific developmental abnormalities: Musculoskeletal systemANREAK 169,285,1971
parenteral/mouse 7 mg/kg (11D pregnant)Reproductive: Specific developmental abnormalities: Gastrointestinal systemANREAK 169,285,1971

Acute Toxicity Data and References

Route/OrganismDoseEffectReference
inhalation/cat Lowest published lethal concentration: 15 mg/m3/4H85GMAT -,52,1982
inhalation/mouse lethal concentration (50 percent kill): 0.01 gm/m3/2HTPKVAL 9,7,1967
inhalation/mouse lethal concentration (50 percent kill): 0.96 ppm/2HTPKVAL 9,7,1967
inhalation/rat Lowest published lethal concentration: 15 mg/m3/4H85GMAT -,52,1982
intramuscular/cat lethal dose (50 percent kill): 3900 µg/kgBehavioral: Tremor

Lung, Thorax, or Respiration: Dyspnea

Gastrointestinal: Nausea or vomiting
13ZGAF -,220,1962
intramuscular/Dog lethal dose (50 percent kill): 3650 µg/kgBehavioral: Tremor

Lung, Thorax, or Respiration: Dyspnea

Gastrointestinal: Nausea or vomiting
13ZGAF -,220,1962
intramuscular/rat lowest published lethal dose: 3 mg/kgBehavioral: Tremor

Gastrointestinal: Hypermotility, diarrhea

Gastrointestinal: Nausea or vomiting
13ZGAF -,220,1962
intraperitoneal/mouse lethal dose (50 percent kill): 4 mg/kgPSEBAA 129,699,1968
intraperitoneal/rabbit lethal dose (50 percent kill): 3250 µg/kgBLLIAX 38,151,1958
intraperitoneal/rat lethal dose (50 percent kill): 2500 µg/kgAPCRAW 4,117,1961
intravenous/mouse lethal dose (50 percent kill): 3900 µg/kgBLLIAX 38,151,1958
intravenous/rat lethal dose (50 percent kill): 1750 µg/kgBehavioral: Somnolence (general depressed activity)

Behavioral: Ataxia

Gastrointestinal: Hypermotility, diarrhea
BLLIAX 38,151,1958
oral/duck lethal dose (50 percent kill): 7190 µg/kgTXAPA9 47,451,1979
oral/human lowest published lethal dose: 171 µg/kgCMEP** -,1,1956
oral/man lowest published toxic dose: 144 mg/kg/24D- intermittentBiochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesteraseTXAPA9 14,603,1969
oral/mouse lethal dose (50 percent kill): 7850 µg/kgBLLIAX 38,151,1958
oral/pigeon lethal dose (50 percent kill): 8480 µg/kgTXAPA9 20,57,1971
oral/quail lethal dose (50 percent kill): 8480 µg/kgTXAPA9 20,57,1971
oral/rabbit lethal dose (50 percent kill): 5 mg/kgGISAAA 27(8),97,1962
oral/rat lethal dose (50 percent kill): 1700 µg/kgTXAPA9 21,315,1972
oral/wild bird lethal dose (50 percent kill): 1780 µg/kgASTTA8 (680),157,1979
skin/rabbit lethal dose (50 percent kill): 24 mg/kgSPEADM 78-1,28,1978
skin/rat lethal dose (50 percent kill): 8200 µg/kgBehavioral: Tremor

Behavioral: Convulsions or effect on seizure threshold

Behavioral: Excitement
TXAPA9 2,88,1960
skin/wild bird lethal dose (50 percent kill): 1800 µg/kgTXAPA9 26,154,1973
subcutaneous/mouse lethal dose (50 percent kill): 15 mg/kgAPFRAD 11,286,1953
subcutaneous/rabbit lethal dose (50 percent kill): 24 mg/kgIAEC** 17JUN1974

Other Multiple Dose Data and References

Route/OrganismDoseEffectReference
oral/Dog lowest published toxic dose: 7.9 mg/kg/168D- intermittentBiochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesteraseHBPTO* 1,59,2001
oral/human lowest published toxic dose: 1.2 mg/kg/24D- intermittentBlood: Changes in serum composition (e.g. TP, bilirubin, cholesterol)

Biochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesterase
HBPTO* 1,59,2001
oral/rat lowest published toxic dose: 15.68 mg/kg/112D- intermittentBiochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesteraseHBPTO* 1,59,2001

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
TOXICOLOGY REVIEWAQMOAC #73-19,1973
TOXICOLOGY REVIEWRREVAH 46,1,1973
TOXICOLOGY REVIEWCNDQA8 10(3),43,1975
TOXICOLOGY REVIEWDTTIAF 80,485,1973
TOXICOLOGY REVIEWMUTAEX 21,93,2006
TOXICOLOGY REVIEWTOLED5 190,107,2009

Standards and Regulations

OrganizationStandardReference
Environmental Protection Agency (EPA) Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) 1988 PESTICIDE SUBJECT TO REGISTRATION OR RE-REGISTRATIONFEREAC 54,7740,1989
Environmental Protection Agency (EPA) Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) 1998 STATUS OF PESTICIDESCancelledRBREV* -,109,1998
Mine Safety and Health Administration (MSHA) STANDARD-airtime-weighted average 0.01 ppm (0.1 mg/m3) (skin)DTLWS* 3,15,1973
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 0.01 ppm (0.11 mg/m3), JUL2008
Occupational Exposure Limit-AUSTRIAMAK-TMW 0.01 ppm (0.1 mg/m3);KZW 0.1 ppm (1 mg/m3), skin, 2007
Occupational Exposure Limit-BELGIUMtime-weighted average 0.05 mg/m3 (vapor, aerosol), Skin, MAR2002
Occupational Exposure Limit-DENMARKtime-weighted average 0.01 ppm (0.1 mg/m3), skin, MAY2011
Occupational Exposure Limit-FINLANDtime-weighted average 0.1 mg/m3, short term exposure limit 0.3 mg/m3, skin, NOV2011
Occupational Exposure Limit-FRANCEVME 0.01 ppm (0.1 mg/m3), Skin, FEB2006
Occupational Exposure Limit-ICELANDtime-weighted average 0.01 ppm (0.1 mg/m3), skin, NOV2011
Occupational Exposure Limit-INDIAtime-weighted average 0.01 ppm (0.1 mg/m3), Skin, JAN1993
Occupational Exposure Limit-KOREAtime-weighted average 0.01 ppm (0.1 mg/m3), skin, 2006
Occupational Exposure Limit-MEXICOtime-weighted average 0.01 ppm (0.1 mg/m3);short term exposure limit 0.03 ppm (skin), 2004
Occupational Exposure Limit-NEW ZEALANDtime-weighted average 0.01 ppm (0.11 mg/m3), skin, JAN2002
Occupational Exposure Limit-PERUtime-weighted average 0.005 ppm (0.05 mg/m3), JUL2005
Occupational Exposure Limit-RUSSIAshort term exposure limit 0.02 mg/m3, Skin, JUN2003
Occupational Exposure Limit-SWITZERLANDMAK-week 0.01 ppm (0.1 mg/m3), skin, JAN2011
Occupational Exposure Limit-THAILANDtime-weighted average 0.1 mg/m3, JAN1993
Occupational Exposure Limit-THE NETHERLANDSMAC-TGG 0.1 mg/m3, 2003
Occupational Exposure Limit-THE PHILIPPINEStime-weighted average 0.1 mg/m3, Skin, JAN1993
Occupational Exposure Limit-TURKEYtime-weighted average 0.1 mg/m3, Skin, JAN1993
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Construction)8H time-weighted average 0.1 mg/m3 (skin)CFRGBR 29,1926.55,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Federal Contractors)8H time-weighted average 0.1 mg/m3 (skin)CFRGBR 41,50-204.50,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (General Industry)8H time-weighted average 0.1 mg/m3 (skin)CFRGBR 29,1910.1000,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Shipyards)8H time-weighted average 0.1 mg/m3 (skin)CFRGBR 29,1915.1000,1993

NIOSH Documentation and Surveillance

OrganizationStandardReference
National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Level TO DEMETON-air10H time-weighted average 0.1 mg/m3 (Sk)NIOSH* DHHS #92-100,1992

Status in Federal Agencies

OrganizationReference
EPA GENETOX PROGRAM 1988, Negative: E coli polA without S9; D melanogaster Sex-linked lethal
EPA GENETOX PROGRAM 1988, Positive/dose response: In vitro UDS-human fibroblast; TRP reversion
EPA GENETOX PROGRAM 1988, Positive: B subtilis rec assay; Histidine reversion-Ames test
EPA GENETOX PROGRAM 1988, Positive: S cerevisiae-homozygosis
NIOSH Analytical Method, 1994: Demeton, 5514
On EPA IRIS database
Page last reviewed: November 16, 2018