NIOSH logo and tagline

Phosphonodithioic acid, ethyl-, O-ethyl S-phenyl ester

RTECS #
TA5950000
CAS #
944-22-9
See: NMAM or OSHA Methods
Updated
December 2016
Molecular Weight
246.34
Molecular Formula
C10H15OPS2
Synonyms
Difonate
Difonatul
Dyfonate
Dyphonate
ENT 25,796
Fonofos
Fonofos (ACGIH)
Fonophos
N-2790
O-Aethyl-S-phenyl-aethyl-dithiophosphonat (German)
O-Ethyl S-phenyl ethyldithiophosphonate
O-Ethyl-S-phenyl ethylphosphonodithioate
OMS 410
Stauffer N 2790

Acute Toxicity Data and References

Route/OrganismDoseEffectReference
inhalation/rat lethal concentration (50 percent kill): 1900 mg/m3/1H85JFAN A214,1983
oral/Dog lethal dose (50 percent kill): 3 mg/kgVTYMAC 74,1119,1979
oral/domestic animal lethal dose (50 percent kill): 1300 µg/kgAJVRAH 43,1672,1982
oral/pigeon lethal dose (50 percent kill): 13300 µg/kgASTTA8 (680),157,1979
oral/quail lethal dose (50 percent kill): 12 mg/kgBehavioral: Convulsions or effect on seizure threshold

Behavioral: Ataxia

Lung, Thorax, or Respiration: Dyspnea
EESADV 8,551,1984
oral/rat lethal dose (50 percent kill): 3 mg/kgUSXXAM #6193990
oral/wild bird lethal dose (50 percent kill): 10 mg/kgASTTA8 (680),157,1979
skin/guinea pig lethal dose (50 percent kill): 278 mg/kg28ZEAL 5,118,1976
skin/rabbit lethal dose (50 percent kill): 25 mg/kgUSXXAM #6193990
skin/rat lethal dose (50 percent kill): 147 mg/kgWRPCA2 9,119,1970
unreported route/mammal (species unspecified) lethal dose (50 percent kill): 17 mg/kg30ZDA9 -,385,1971

Reviews

OrganizationStandardReference
American Conference of Governmental Industrial Hygienists (ACGIH)Threshold Limit Value-time-weighted average 0.01 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 REVIEWMUREAV 760,1,2014
TOXICOLOGY REVIEWTXAPA9 268,157,2013

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 PESTICIDESUnsupportedRBREV* -,121,1998
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 0.1 mg/m3, JUL2008
Occupational Exposure Limit-AUSTRIAMAK-TMW 0.1 mg/m3;KZW 0.2 mg/m3, skin, 2007
Occupational Exposure Limit-BELGIUMtime-weighted average 0.1 mg/m3, Skin, MAR2002
Occupational Exposure Limit-DENMARKtime-weighted average 0.1 mg/m3, skin, MAY2011
Occupational Exposure Limit-FRANCEVME 0.1 mg/m3, Skin, FEB2006
Occupational Exposure Limit-ICELANDtime-weighted average 0.1 mg/m3, skin, NOV2011
Occupational Exposure Limit-KOREAtime-weighted average 0.1 mg/m3, skin, 2006
Occupational Exposure Limit-MEXICOtime-weighted average 0.1 mg/m3, 2004
Occupational Exposure Limit-NEW ZEALANDtime-weighted average 0.1 mg/m3, skin, JAN2002
Occupational Exposure Limit-PERUtime-weighted average 0,1 mg/m3, JUL2005
Occupational Exposure Limit-SWITZERLANDMAK-week 0.1 mg/m3, inhal, skin, JAN2011
Occupational Exposure Limit-THE NETHERLANDSMAC-TGG 0.1 mg/m3, 2003

NIOSH Documentation and Surveillance

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

Status in Federal Agencies

OrganizationReference
EPA GENETOX PROGRAM 1988, Inconclusive: B subtilis rec assay; E coli polA without S9
EPA GENETOX PROGRAM 1988, Negative: Histidine reversion-Ames test
EPA GENETOX PROGRAM 1988, Negative: In vitro UDS-human fibroblast; TRP reversion
EPA GENETOX PROGRAM 1988, Negative: S cerevisiae-homozygosis
NIOSH Analytical Method, 1994: Organophosphorus pesticides, 5600
On EPA IRIS database
Page last reviewed: November 16, 2018