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Registry of Toxic Effects of Chemical Substances (RTECS)

Phosphorothioic acid, O,O-dimethyl O-(4-(methylthio)-m-tolyl) ester

RTECS #

TF9625000

CAS #

55-38-9

Updated

June 2017

Molecular Weight

278.34

Molecular Formula

C10H15O3PS2

Synonyms

4-Methylmercapto-3-methylphenyl dimethyl thiophosphate
B 29493
BAY 29493
Baycid
Bayer 29493
Bayer 9007
Bayer S-1752
Baytex
ENT 25,540
Entex
Fenthion
Fenthion (ACGIH)
Fenthion 4E
Fenthion-methyl
Lebaycid
m-Cresol, 4-(methylthio)-, O-ester with O,O-dimethyl phosphorothioate
Mercaptophos
MPP (pesticide)
NCI-C08651
O,O-Dimethyl O-(3-methyl-4-methylmercaptophenyl)phosphorothioate
O,O-Dimethyl O-(4-(methylthio)-m-tolyl) phosphorothioate
O,O-Dimethyl O-(4-methylthio-3-methylphenyl) phosphorothioate
O,O-Dimethyl O-3-methyl-4-methylthiophenyl phosphorothioate
O,O-Dimethyl O-4-(methylmercapto)-3-methylphenyl phosphorothioate
O,O-Dimethyl-O-(3-methyl-4-methylthio-fenyl)-monothiofosfaat (Dutch)
O,O-Dimethyl-O-(3-methyl-4-methylthiophenyl)-monothiophosphat (German)
O,O-Dimethyl-O-(3-methyl-4-methylthio-phenyl)-thionophosphat (German)
O,O-Dimethyl-O-4-(methylmercapto)-3-methylphenyl thiophosphate
O,O-Dimetil-O-(3-metil-4-metiltio-fenil)-monotiofosfato (Italian)
OMS 2
Phosphorothioic acid O,O-dimethyl O-(3-methyl-4-(methylthio)phenyl) ester
Queletox
S 1752
Spotton
Sulfidophos
Talodex
Thiophosphate de O,O-dimethyle et de O-(3-methyl-4-methylthiophenyle) (French)
Tiguvon

Mutation Data and Reference

System TestRoute/Organism/TissueDoseReference
mutation in microorganisms/Salmonella typhimurium333 µg/plate (-enzymatic activation step)ENMUDM 8(Suppl 7),1,1986
sister chromatid exchangelung/hamster40 mg/LENMUDM 4,621,1982

Reproductive Effects Data and References

Route/OrganismDoseEffectReference
intraperitoneal/mouse 40 mg/kg (11D pregnant)Reproductive: Effects on embryo or fetus: Fetotoxicity (except death, e.g., stunted fetus)

Reproductive: Specific developmental abnormalities: Craniofacial (including nose and tongue)

Reproductive: Specific developmental abnormalities: Musculoskeletal system
TXAPA9 24,324,1973
oral/rat 10 mg/kg (6-15D pregnant)Reproductive: Other effects on femaleTIHEEC 14,869,1998
oral/mouse 1050 mg/kg (multigenerations)Reproductive: Effects on fertility: Female fertility index (e.g., # females pregnant per # sperm positive females; # females pregnant per # females mated)

Reproductive: Effects on newborn: Viability index (e.g., # alive at day 4 per # born alive)

Reproductive: Effects on newborn: Weaning or lactation index (e.g., # alive at weaning per # alive at day 4)
TXAPA9 26,29,1973

Tumorigenic Data and References

Route/OrganismDoseEffectReference
oral/mouse lowest published toxic dose: 1730 mg/kg/103W- continuousTumorigenic: Equivocal tumorigenic agent by RTECS criteria

Skin and Appendages: Tumors
NCITR* NCI-TR-103,1979

Acute Toxicity Data and References

Route/OrganismDoseEffectReference
In Vitro/Rat, neurons Inhibitor Concentration Low: 40 µmol/L/1HIn Vitro Toxicity Studies: Other assaysNRTXDN 44,204,2014
inhalation/guinea pig Lowest published lethal concentration: 1 gm/m3/2H85GYAV -,27,1971
inhalation/mouse Lowest published lethal concentration: 1 gm/m3/2H85GYAV -,27,1971
inhalation/rabbit Lowest published lethal concentration: 1 gm/m3/2H85GYAV -,27,1971
inhalation/rat lethal concentration (50 percent kill): 800 mg/m3/4H85INA8 6,646,1991
intracerebral/mouse lethal dose (50 percent kill): 50 mg/kgPCBPBS 8,302,1978
intramuscular/Dog lethal dose (50 percent kill): 40 mg/kgVMRVAN (2-3),273,1967
intramuscular/domestic animal lethal dose (50 percent kill): 46 mg/kgBiochemical: Enzyme inhibition, induction, or change in blood or tissue levels: Reactivates cholinesteraseVETNAL 54(12),94,1978
intramuscular/mammal (species unspecified) lethal dose (50 percent kill): 46200 µg/kgBehavioral: Somnolence (general depressed activity)

Behavioral: Food intake (animal)

Behavioral: Muscle contraction or spasticity
VETNAL 54(12),94,1978
intraperitoneal/chicken lethal dose (50 percent kill): 20 mg/kgEQSFAP 3,173,1974
intraperitoneal/guinea pig lethal dose (50 percent kill): 310 mg/kgTXAPA9 6,86,1964
intraperitoneal/mouse lowest published toxic dose: 300 mg/kgBrain and Coverings: Other degenerative changesTOLED5 135,89,2002
intraperitoneal/mouse lethal dose (50 percent kill): 125 mg/kgTXAPA9 6,86,1964
intraperitoneal/rat lethal dose (50 percent kill): 260 mg/kgTXAPA9 6,86,1964
intravenous/mouse lethal dose (50 percent kill): 320 mg/kgCSLNX* NX#00142
oral/chicken lethal dose (50 percent kill): 20 mg/kgEQSFAP 3,173,1974
oral/duck lethal dose (50 percent kill): 5900 µg/kgDOEAAH 35,25,1979
oral/guinea pig lethal dose (50 percent kill): 260 mg/kgTXAPA9 6,86,1964
oral/mammal (species unspecified) lethal dose (50 percent kill): 105 mg/kgBehavioral: Somnolence (general depressed activity)

Behavioral: Food intake (animal)

Behavioral: Muscle contraction or spasticity
VETNAL 54(12),94,1978
oral/man lowest published toxic dose: 1429 µL/kgLung, Thorax, or Respiration: Other changes

Kidney, Ureter, and Bladder: Other changes

Skin and Appendages: Other: Sweating
JJAMA* 14,789,1990
oral/man lowest published toxic dose: 3571 µL/kgEye: Miosis (pupilliary constriction)

Behavioral: General anesthetic

Behavioral: Convulsions or effect on seizure threshold
YAKUD5 32,1456,1990
oral/man lowest published toxic dose: 643 µL/kgPeripheral Nerve and Sensation: Fasciculations

Behavioral: Ataxia

Cardiac: Pulse rate decreased with fall in BP
HETOEA 14,600,1995
oral/man lowest published toxic dose: 257 mg/kgCardiac: Pulse rate increased without fall in BP

Gastrointestinal: Hypermotility, diarrhea

Gastrointestinal: Nausea or vomiting
JTCTDW 19,425,1982
oral/mouse lethal dose (50 percent kill): 88100 µg/kgHOEKAN 30,53,1980
oral/pigeon lethal dose (50 percent kill): 1780 µg/kgASTTA8 (680),157,1979
oral/quail lethal dose (50 percent kill): 11 mg/kgTXAPA9 20,57,1971
oral/rabbit lowest published toxic dose: 150 mg/kgLung, Thorax, or Respiration: Structural or functional change in trachea or bronchi

Lung, Thorax, or Respiration: Emphysema

Blood: Hemorrhage
JTCTDW 46,711,2008
oral/rabbit lethal dose (50 percent kill): 150 mg/kgBehavioral: Muscle weakness

Gastrointestinal: Changes in structure or function of salivary glands

Kidney, Ureter, and Bladder: Other changes
BWHOA6 29,205,1963
oral/rat lethal dose (50 percent kill): 180 mg/kgKSKZAN 16(2),59,1978
oral/wild bird lethal dose (50 percent kill): 1300 µg/kgTXAPA9 21,315,1972
oral/woman lowest published toxic dose: 1200 µL/kgBehavioral: Coma

Cardiac: Pulse rate decreased with fall in BP

Gastrointestinal: Hypermotility, diarrhea
HETOEA 14,600,1995
oral/woman lowest published toxic dose: 525 mg/kgEye: Miosis (pupilliary constriction)

Behavioral: Muscle contraction or spasticity

Lung, Thorax, or Respiration: Respiratory depression
HETOEA 9,187,1990
skin/duck lethal dose (50 percent kill): 44 mg/kgTXAPA9 47,451,1979
skin/mouse lethal dose (50 percent kill): 500 mg/kgOYYAA2 1,74,1967
skin/rat lethal dose (50 percent kill): 330 mg/kgBehavioral: Tremor

Behavioral: Convulsions or effect on seizure threshold

Behavioral: Excitement
TXAPA9 2,88,1960
subcutaneous/mouse lethal dose (50 percent kill): 144 mg/kgOYYAA2 1,74,1967
subcutaneous/rat lowest published toxic dose: 0.8 gm/kgBrain and Coverings: Other degenerative changes

Lung, Thorax, or Respiration: Other changes

Liver: Other changes
BCLPT* 100,308,2007
subcutaneous/rat lowest published toxic dose: 0.8 gm/kgCardiac: Cardiomyopathy including infarction

Biochemical: Metabolism (intermediary): Other proteins

Biochemical: Metabolism (intermediary): Effect on inflammation or mediation of inflammation
JTCTDW 46,67,2008
subcutaneous/rat lowest published toxic dose: 0.8 gm/kgGastrointestinal: Changes in structure or function of exocrine pancreas

Blood: Changes in serum composition (e.g. TP, bilirubin, cholesterol)

Biochemical: Enzyme inhibition, induction, or change in blood or tissue levels: Multiple enzyme effects
JTCTDW 46,141,2008
unreported route/human lowest published lethal dose: 50 mg/kg85INA8 5,267,1986

Other Multiple Dose Data and References

Route/OrganismDoseEffectReference
intraperitoneal/rat lowest published toxic dose: 1200 mg/kg/60D- continuousRelated to Chronic Data: Death in the "MULTIPLE DOSE" data type fieldTXAPA9 6,86,1964
oral/domestic bird lowest published toxic dose: 7500 µg/kg/5D- continuousBehavioral: Food intake (animal)

Nutritional and Gross Metabolic: Weight loss or decreased weight gain

Related to Chronic Data: Death in the "MULTIPLE DOSE" data type field
AECTCV 11,617,1982
oral/rat lowest published toxic dose: 172 mg/kg/6D- intermittentPeripheral Nerve and Sensation: Structural change in nerve or sheath

Blood: Changes in bone marrow not included in above

Biochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesterase
ZYYZEW 2,126,1988
skin/chicken lowest published toxic dose: 35 mg/kg/7D- intermittentBehavioral: Ataxia

Nutritional and Gross Metabolic: Weight loss or decreased weight gain

Biochemical: Enzyme inhibition, induction, or change in blood or tissue levels: Other esterases
JTEHD6 21,455,1987
skin/chicken lowest published toxic dose: 24 mg/kg/24W- intermittentBlood: Changes in serum composition (e.g. TP, bilirubin, cholesterol)

Musculoskeletal: Other changes

Biochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesterase
VHTODE 41,302,1999
skin/rat lowest published toxic dose: 380 mg/kg/19D- intermittentBrain and Coverings: Other degenerative changes

Blood: Changes in serum composition (e.g. TP, bilirubin, cholesterol)

Biochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesterase
BWHOA6 29,205,1963
skin/rat lowest published toxic dose: 3225 mg/kg/43W- intermittentBrain and Coverings: Other degenerative changesTXAPA9 104,440,1990
skin/rat lowest published toxic dose: 365 mg/kg/5D- intermittentRelated to Chronic Data: Death in the "MULTIPLE DOSE" data type fieldBWHOA6 29,205,1963
subcutaneous/rat lowest published toxic dose: 5200 mg/kg/1Y- intermittentEye: Retinal changes pigmentary deposition, retinitis, other)

Liver: Other changes

Biochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesterase
ENVRAL 30,453,1983
subcutaneous/rat lowest published toxic dose: 260 mg/kg/13W- intermittentEye: Retinal changes pigmentary deposition, retinitis, other)TOXID9 15,26,1995
unreported route/rat lowest published toxic dose: 3000 mg/kg/40W- intermittentBrain and Coverings: Other degenerative changes

Biochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesterase
HBPTO* 1,878,2001

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
American Conference of Governmental Industrial Hygienists (ACGIH)Threshold Limit Value-Not classifiable as a human carcinogenDTLVS* TLV/BEI,2013
TOXICOLOGY REVIEWRREVAH 46,1,1973
TOXICOLOGY REVIEWCNDQA8 10(3),43,1975
TOXICOLOGY REVIEWRREVAH 63,1,1976
TOXICOLOGY REVIEWMUTAEX 21,93,2006
TOXICOLOGY REVIEWENTOX* -,325,2005
TOXICOLOGY REVIEWENTOX* -,306,2005
TOXICOLOGY REVIEWENTOX* -,308,2005
TOXICOLOGY REVIEWMUREAV 584,1,2005
TOXICOLOGY REVIEWHETOEA 26,321,2007
TOXICOLOGY REVIEWFCTOD7 47,2906,2009
TOXICOLOGY REVIEWFCTOD7 47,2926,2009
TOXICOLOGY REVIEWNTAPM* -,629,1995
TOXICOLOGY REVIEWTOLED5 190,107,2009
TOXICOLOGY REVIEWMUREAV 721,27,2011
TOXICOLOGY REVIEWTXAPA9 258,309,2012
TOXICOLOGY REVIEWTOLED5 230,434,2014
TOXICOLOGY REVIEWTXAPA9 268,157,2013
TOXICOLOGY REVIEWMUREAV 802,1,2016

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 PESTICIDESSupportedRBREV* -,120,1998
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 0.2 mg/m3, JUL2008
Occupational Exposure Limit-AUSTRIAMAK-TMW 0.2 mg/m3;KZW 2 mg/m3, inhal, skin, 2007
Occupational Exposure Limit-BELGIUMtime-weighted average 0.2 mg/m3, Skin, MAR2002
Occupational Exposure Limit-DENMARKtime-weighted average 0.1 mg/m3, skin, MAY2011
Occupational Exposure Limit-GERMANYMAK 0.2 mg/m3, inhal, 2011
Occupational Exposure Limit-ICELANDtime-weighted average 0.1 mg/m3, skin, NOV2011
Occupational Exposure Limit-JAPANOccupational Exposure Limit 0.2 mg/m3, skin, MAY2012
Occupational Exposure Limit-KOREAtime-weighted average 0.2 mg/m3, skin, 2006
Occupational Exposure Limit-NEW ZEALANDtime-weighted average 0.2 mg/m3, skin, JAN2002
Occupational Exposure Limit-PERUtime-weighted average 0,2 mg/m3, JUL2005
Occupational Exposure Limit-POLANDMAC(time-weighted average) 0.2 mg/m3, JAN1999
Occupational Exposure Limit-SWITZERLANDMAK-week 0.1 mg/m3, KZG-week 0.2 mg/m3, inhal, skin, JAN2011
Occupational Exposure Limit-THE NETHERLANDSMAC-TGG 0.1 mg/m3, 2003

NIOSH Documentation and Surveillance

OrganizationStandardReference
National Occupational Exposure Survey 1983Hazard Code X9267; Number of Industries 4; Total Number of Facilities 221; Number of Occupations 6; Total Number of Employees Exposed 2142; Total Number of Female Employees Exposed 442

Status in Federal Agencies

OrganizationReference
EPA GENETOX PROGRAM 1988, Inconclusive: B subtilis rec assay; E coli polA without S9
EPA GENETOX PROGRAM 1988, Inconclusive: D melanogaster Sex-linked lethal
EPA GENETOX PROGRAM 1988, Inconclusive: Histidine reversion-Ames test
EPA GENETOX PROGRAM 1988, Negative: In vitro UDS-human fibroblast; TRP reversion
EPA GENETOX PROGRAM 1988, Negative: S cerevisiae-homozygosis
NCI Carcinogenesis Bioassay (feed);clear evidence:mouseNCITR* NCI-TR-103,1979
NCI Carcinogenesis Bioassay (feed);no evidence:ratNCITR* NCI-TR-103,1979
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