Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content

Registry of Toxic Effects of Chemical Substances (RTECS)

2-Imidazolidinethione

RTECS #

NI9625000

CAS #

96-45-7; 96-46-8

Updated

June 2017

Molecular Weight

102.17

Molecular Formula

C3H6N2S

Synonyms

1,3-Ethylene-2-thiourea
1,3-Ethylenethiourea
2-Imadazoline-2-thiol
2-Mercaptoimidazoline
2-Merkaptoimidazolin (Czech)
2-Thiol-dihydroglyoxaline
4,5-Dihydroimidazole-2(3H)-thione
Akrochem etu-22
Ethylene thiourea
Ethylene thiouree (French)
Ethylenethiourea
ETU
Imidazole-2(3H)-thione, 4,5-dihydro-
Imidazoline, 2-mercapto-
Imidazoline-2-thiol
N,N'-Ethylenethiourea
NA-22
NA-22-D
NCI-C03372
Pennac CRA
RCRA waste number U116
Robac 22
Rodanin S-62 (Czech)
Sanceller 22
Sodium-22 neoprene accelerator
Urea, 1,3-ethylene-2-thio-
USAF EL-62
Vulkacit npv/C2
Warecure C

Skin and Eye Irritation and References

Route/OrganismDoseEffectReference
eye /rabbit 500 mg/24H mild85JCAE -,988,1986

Mutation Data and Reference

System TestRoute/Organism/TissueDoseReference
Cytogenetic Analysisparenteral/rat200 mg/kgMUREAV 38,349,1976
Cytogenetic Analysisoral/rat200 mg/kgCSHCAL 4,267,1977
DNA Damageintraperitoneal/mouse2 gm/kgMUREAV 391,201,1997
DNA Damage/Bacillus subtilis2 mg/discPMRSDJ 1,175,1981
DNA repair/Escherichia coli500 mg/LPMRSDJ 1,195,1981
DNA repair/Salmonella typhimurium20 mg/plateMUREAV 38,122,1976
DNA repair/Saccharomyes cerevisiae300 mg/LPMRSDJ 1,502,1981
gene conversion and mitotic recombination/Saccharomyes cerevisiae50 mg/LPMRSDJ 1,491,1981
gene conversion and mitotic recombinationoral/Drosophila melanogaster1 mmol/L/48HMUREAV 518,95,2002
host-mediated assaySalmonella typhimurium/mouse6 gm/kgMUREAV 56,111,1977
morphological transformkidney/hamster80 µg/LBJCAAI 37,873,1978
mutation in microorganismslymphocyte/mouse1800 mg/L (+enzymatic activation step)EMMUEG 12,85,1988
mutation in microorganisms/Escherichia coli200 mg/L (+enzymatic activation step)PMRSDJ 1,396,1981
mutation in microorganisms/Salmonella typhimurium1 mmol/L (+enzymatic activation step)EXPEAM 31,214,1975
mutation in microorganisms/Salmonella typhimurium20 µg/plate (-enzymatic activation step)BJCAAI 37,873,1978
mutation in microorganisms/Saccharomyes cerevisiae5 mmol/L (-enzymatic activation step)MGGEAE 174,39,1979
phage inhibition capacity/Escherichia coli10 gm/LPMRSDJ 1,224,1981
sex chromosome loss and nondisjunction/Saccharomyes cerevisiae100 mg/LPMRSDJ 1,468,1981
sex chromosome loss and nondisjunction/Aspergillus nidulans39200 µmol/LMUREAV 172,139,1986
specific locus testmultiple/Drosophila melanogaster500 µmol/LMUREAV 395,229,1997

Reproductive Effects Data and References

Route/OrganismDoseEffectReference
inhalation/rat 120 mg/m3/3H (7-14D pregnant)Reproductive: Effects on embryo or fetus: Fetotoxicity (except death, e.g., stunted fetus)

Reproductive: Effects on embryo or fetus: Fetal death
NTIS** PB277-077
inhalation/rat 27200 µg/m3/3H (7-14D pregnant)Reproductive: Specific developmental abnormalities: Musculoskeletal systemNTIS** PB277-077
intraperitoneal/rat 30 mg/kg (17D pregnant)Reproductive: Specific developmental abnormalities: Central nervous system

Reproductive: Effects on newborn: Weaning or lactation index (e.g., # alive at weaning per # alive at day 4)
TJADAB 34,449,1986
intraperitoneal/rat 30 mg/kg (19D pregnant)Reproductive: Effects on newborn: Viability index (e.g., # alive at day 4 per # born alive)TJADAB 34,449,1986
intraperitoneal/rat 30 mg/kg (12D pregnant)Reproductive: Effects on fertility: Litter size (e.g., # fetuses per litter; measured before birth)

Reproductive: Specific developmental abnormalities: Central nervous system

Reproductive: Effects on newborn: Viability index (e.g., # alive at day 4 per # born alive)
CGANE7 30,121,1990
intraperitoneal/rat 30 mg/kg (13D pregnant)Reproductive: Effects on newborn: Growth statistics (e.g., reduced weight gain)CGANE7 30,121,1990
oral/rat 84 mg/kg (11-14D pregnant)Reproductive: Effects on embryo or fetus: Fetotoxicity (except death, e.g., stunted fetus)JHSCFD 45,184,1999
oral/rat 60 mg/kg (13D pregnant)Reproductive: Specific developmental abnormalities: Urogenital systemTJADAB 24,131,1981
oral/rat 100 mg/kg (13D pregnant)Reproductive: Specific developmental abnormalities: Gastrointestinal systemSEIJBO 18,241,1978
oral/rat 60 mg/kg (13D pregnant)Reproductive: Specific developmental abnormalities: Craniofacial (including nose and tongue)FCTOD7 20,273,1982
oral/rat 10 mg/kg (17D pregnant)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)
ATSUDG 4,292,1980
oral/rat 50 mg/kg (12D pregnant)Reproductive: Effects on embryo or fetus: Fetotoxicity (except death, e.g., stunted fetus)

Reproductive: Specific developmental abnormalities: Musculoskeletal system
SEIJBO 18,241,1978
oral/rat 30 mg/kg (15D pregnant)Reproductive: Specific developmental abnormalities: Central nervous system

Reproductive: Effects on newborn: Weaning or lactation index (e.g., # alive at weaning per # alive at day 4)
FAATDF 9,415,1987
oral/mouse 1600 mg/kg (12D pregnant)Reproductive: Effects on newborn: Sex ratioJTEHD6 13,747,1984
oral/mouse 2 gm/kg (7-16D pregnant)Reproductive: Specific developmental abnormalities: Musculoskeletal systemJTEHD6 5,821,1979
oral/mouse 2 gm/kg (10D pregnant)Reproductive: Specific developmental abnormalities: Craniofacial (including nose and tongue)TJADAB 23,335,1981
oral/mouse 2 gm/kg (12D pregnant)Reproductive: Effects on fertility: Post- implantation mortality (e.g., dead and/or resorbed implants per total number of implants)

Reproductive: Effects on embryo or fetus: Fetal death

Reproductive: Specific developmental abnormalities: Musculoskeletal system
TJADAB 27,57A,1983
oral/mouse 2400 mg/kg (12D pregnant)Reproductive: Effects on embryo or fetus: Fetotoxicity (except death, e.g., stunted fetus)TJADAB 27,57A,1983
oral/cat 600 mg/kg (16-35D pregnant)Reproductive: Specific developmental abnormalities: Eye, ear

Reproductive: Specific developmental abnormalities: Body wall

Reproductive: Specific developmental abnormalities: Craniofacial (including nose and tongue)
TJADAB 18,311,1978
oral/rabbit 1120 mg/kg (7-20D pregnant)Reproductive: Effects on fertility: Post- implantation mortality (e.g., dead and/or resorbed implants per total number of implants)TJADAB 7,243,1973
oral/rabbit 140 mg/kg (7-20D pregnant)Reproductive: Specific developmental abnormalities: Central nervous systemTJADAB 7,243,1973
oral/hamster 600 mg/kg (11D pregnant)Reproductive: Specific developmental abnormalities: Musculoskeletal systemJTEHD6 11,287,1983
oral/hamster 6480 mg/kg (6-18D pregnant)Reproductive: Specific developmental abnormalities: Craniofacial (including nose and tongue)

Reproductive: Specific developmental abnormalities: Musculoskeletal system

Reproductive: Specific developmental abnormalities: Gastrointestinal system
SEIJBO 18,11,1978
oral/hamster 2400 mg/kg (11D pregnant)Reproductive: Effects on fertility: Post- implantation mortality (e.g., dead and/or resorbed implants per total number of implants)

Reproductive: Effects on embryo or fetus: Fetal death
JTEHD6 11,287,1983
oral/hamster 2160 mg/kg (6-13D pregnant)Reproductive: Effects on embryo or fetus: Fetotoxicity (except death, e.g., stunted fetus)SEIJBO 18,11,1978
oral/hamster 1200 mg/kg (11D pregnant)Reproductive: Specific developmental abnormalities: Central nervous system

Reproductive: Specific developmental abnormalities: Craniofacial (including nose and tongue)
JTEHD6 11,287,1983
oral/rat 3.6 mg/kg (7-20D preg/22D after birth)Reproductive: Effects on fertility: Post- implantation mortality (e.g., dead and/or resorbed implants per total number of implants)

Reproductive: Effects on embryo or fetus: Fetal death

Reproductive: Specific developmental abnormalities: Endocrine system
FCTOD7 59,261,2013
skin/rat 100 mg/kg (12-13D pregnant)Reproductive: Specific developmental abnormalities: Central nervous system

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

Reproductive: Specific developmental abnormalities: Musculoskeletal system
TXAPA9 41,35,1977
skin/rat 2800 mg/kg (7D prior to copulation/1-21D pregnant)Reproductive: Maternal effects: Parturition

Reproductive: Effects on newborn: Stillbirth

Reproductive: Effects on newborn: Growth statistics (e.g., reduced weight gain)
TOXID9 12,102,1992
subcutaneous/rat 80 mg/kg (13D pregnant)Reproductive: Effects on embryo or fetus: Fetotoxicity (except death, e.g., stunted fetus)

Reproductive: Specific developmental abnormalities: Central nervous system

Reproductive: Specific developmental abnormalities: Craniofacial (including nose and tongue)
TXAPA9 48,229,1979
subcutaneous/rat 80 mg/kg (13D pregnant)Reproductive: Specific developmental abnormalities: Musculoskeletal system

Reproductive: Specific developmental abnormalities: Homeostasis
TXAPA9 48,229,1979
unreported route/rat 300 mg/kg (12D pregnant)Reproductive: Specific developmental abnormalities: Central nervous system

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

Reproductive: Specific developmental abnormalities: Musculoskeletal system
AHEMA5 9,89,1980

Tumorigenic Data and References

Route/OrganismDoseEffectReference
oral/mouse lowest published toxic dose: 87360 mg/kg/2Y- continuousTumorigenic: Carcinogenic by RTECS criteria

Liver: Tumors

Endocrine: Thyroid tumors
NTPTR* NTP-TR-388,1992
oral/mouse lowest published toxic dose: 77 gm/kg/82W- continuousTumorigenic: Carcinogenic by RTECS criteria

Liver: Tumors

Blood: Lymphoma including Hodgkin's disease
JNCIAM 42,1101,1969
oral/mouse lowest published toxic dose: 86520 mg/kg/103W- continuousTumorigenic: Carcinogenic by RTECS criteria

Liver: Tumors

Endocrine: Thyroid tumors
NTIS** PB92-191618
oral/rat lowest published toxic dose: 10920 mg/kg/2Y- continuousTumorigenic: Carcinogenic by RTECS criteria

Endocrine: Thyroid tumors
NTPTR* NTP-TR-388,1992
oral/rat lowest published toxic dose: 5306 mg/kg/77W- continuousTumorigenic: Carcinogenic by RTECS criteria

Lung, Thorax, or Respiration: Tumors

Endocrine: Thyroid tumors
JNCIAM 49,583,1972
oral/rat toxic dose: 11466 mg/kg/78W- continuousTumorigenic: Carcinogenic by RTECS criteria

Endocrine: Thyroid tumors
JJIND8 67,75,1981
oral/rat toxic dose: 44 gm/kg/2Y- continuousTumorigenic: Carcinogenic by RTECS criteria

Endocrine: Thyroid tumors

Reproductive: Tumorigenic effects: Testicular tumors
EJTXAZ 9,303,1976
oral/rat toxic dose: 146 gm/kg/2Y- continuousTumorigenic: Carcinogenic by RTECS criteria

Endocrine: Thyroid tumors
EJTXAZ 9,303,1976
oral/rat toxic dose: 9125 mg/kg/2Y- continuousTumorigenic: Carcinogenic by RTECS criteria

Endocrine: Tumors

Endocrine: Thyroid tumors
FCTXAV 13,493,1975
oral/rat toxic dose: 5470 mg/kg/26W- continuousTumorigenic: Equivocal tumorigenic agent by RTECS criteria

Liver: Tumors
GTPZAB 32(2),25,1988
oral/rat lowest published toxic dose: 2737.5 mg/kg/1Y- continuousTumorigenic: Neoplastic by RTECS criteria

Endocrine: Thyroid tumors
JAFCAU 21,324,1973
oral/rat lowest published toxic dose: 5475 mg/kg/1Y- continuousTumorigenic: Carcinogenic by RTECS criteria

Endocrine: Thyroid tumors
JAFCAU 21,324,1973
oral/rat lowest published toxic dose: 9125 mg/kg/1Y- continuousTumorigenic: Carcinogenic by RTECS criteria

Endocrine: Thyroid tumors
JAFCAU 21,324,1973
oral/rat lowest published toxic dose: 10815 mg/kg/103W- continuousTumorigenic: Carcinogenic by RTECS criteria

Endocrine: Thyroid tumors
NTIS** PB92-191618
oral/rat lowest published toxic dose: 9012.5 mg/kg/103W- continuousTumorigenic: Carcinogenic by RTECS criteria

Endocrine: Thyroid tumors
NTIS** PB92-191618

Acute Toxicity Data and References

Route/OrganismDoseEffectReference
intraperitoneal/mouse lethal dose (50 percent kill): 200 mg/kgNTIS** AD277-689
intraperitoneal/rat lowest published toxic dose: 1000 mg/kgEndocrine: Other changesATSUDG 8,253,1985
oral/mouse lethal dose (50 percent kill): 3 gm/kgTJADAB 21,71,1980
oral/rat lethal dose (50 percent kill): 1832 mg/kgBECTA6 7,19,1972
Tank with water/Daphnia lethal concentration (50 percent kill): 18000 µg/L/21DAQUTO* 7,165,1985
Tank with water/Zebrafish the toxic concentration that affects 50% of the population of interest): 139.9 µmol/L/3DEndocrine: Evidence of thyroid hypofunctionTXAPA9 269,169,2013
Tank with water/Zebrafish the toxic concentration that affects 10% of the population of interest): 22.6 µmol/L/3DEndocrine: Evidence of thyroid hypofunctionTXAPA9 269,169,2013
unreported route/mouse lethal dose (50 percent kill): 7800 mg/kgGTPZAB 30(5),59,1986

Other Multiple Dose Data and References

Route/OrganismDoseEffectReference
inhalation/man lowest published toxic concentration: 10 µg/m3/10Y- intermittentEndocrine: Evidence of thyroid hypofunctionBJIMAG 41,362,1984
oral/mouse lowest published toxic dose: 277.2 mg/kg/7D- continuousLiver: Changes in liver weight

Endocrine: Evidence of thyroid hypofunction
EVHPAZ 110,363,2002
oral/mouse lowest published toxic dose: 840 mg/kg/7D- continuousLiver: Changes in liver weight

Endocrine: Evidence of thyroid hypofunction

Biochemical: Enzyme inhibition, induction, or change in blood or tissue levels: Cytochrome oxidases (indlucing oxidative phosphrylation)
EVHPAZ 110,363,2002
oral/rat lowest published toxic dose: 39.375 mg/kg/7D- intermittentEndocrine: Other changesMUREAV 746,144,2012
oral/rat lowest published toxic dose: 504 mg/kg/28D- continuousNutritional and Gross Metabolic: Weight loss or decreased weight gain

Biochemical: Metabolism (intermediary): Other
TOLED5 225,240,2014
oral/rat lowest published toxic dose: 504 mg/kg/28D- continuousBiochemical: Metabolism (intermediary): OtherTOLED5 225,240,2014
oral/rat lowest published toxic dose: 34.86 mg/kg/7D- continuousEndocrine: Evidence of thyroid hypofunction

Endocrine: Changes in thyroid weight
EVHPAZ 110,363,2002
oral/rat lowest published toxic dose: 29.05 mg/kg/7D- continuousEndocrine: Evidence of thyroid hypofunctionEVHPAZ 110,363,2002
oral/rat lowest published toxic dose: 297 mg/kg/28D- continuousEndocrine: Other changes

Blood: Changes in serum composition (e.g. TP, bilirubin, cholesterol)
ATSUDG 9,339,1986
oral/rat lowest published toxic dose: 764 mg/kg/90D- continuousEndocrine: Other changes

Endocrine: Changes in thyroid weight

Blood: Changes in serum composition (e.g. TP, bilirubin, cholesterol)
JEPTDQ 1(1),147,1977
oral/rat lowest published toxic dose: 220 mg/kg/7W- continuousBehavioral: Food intake (animal)

Endocrine: Changes in thyroid weight

Nutritional and Gross Metabolic: Weight loss or decreased weight gain
TXAPA9 67,264,1983
oral/rat lowest published toxic dose: 3600 mg/kg/17W- continuousEndocrine: Other changes

Endocrine: Changes in thyroid weight

Nutritional and Gross Metabolic: Weight loss or decreased weight gain
BECTA6 7,19,1972
oral/rat lowest published toxic dose: 450 mg/kg/8W- continuousLiver: Changes in liver weightJAFCAU 21,324,1973
oral/rat lowest published toxic dose: 900 mg/kg/8W- continuousEndocrine: Changes in thyroid weight

Nutritional and Gross Metabolic: Weight loss or decreased weight gain
JAFCAU 21,324,1973
oral/rat lowest published toxic dose: 1800 mg/kg/8W- continuousKidney, Ureter, and Bladder: Changes in kidney weightJAFCAU 21,324,1973
oral/rat lowest published toxic dose: 5475 mg/kg/26W- continuousEndocrine: Changes in spleen weightJAFCAU 21,324,1973
oral/rat lowest published toxic dose: 10950 mg/kg/1Y- continuousEndocrine: Evidence of thyroid hypofunctionJAFCAU 21,324,1973
oral/rat lowest published toxic dose: 75 mg/kg/8W- continuousNutritional and Gross Metabolic: Weight loss or decreased weight gainJAFCAU 21,324,1973
oral/rat lowest published toxic dose: 375 mg/kg/8W- continuousLiver: Changes in liver weight

Endocrine: Changes in thyroid weight
JAFCAU 21,324,1973
oral/rat lowest published toxic dose: 1140.6 mg/kg/26W- continuousEndocrine: Evidence of thyroid hypofunctionJAFCAU 21,324,1973
oral/rat lowest published toxic dose: 2281 mg/kg/1Y- continuousEndocrine: Evidence of thyroid hyperfunctionJAFCAU 21,324,1973
oral/rat lowest published toxic dose: 2281 mg/kg/26W- continuousCardiac: Changes in heart weightJAFCAU 21,324,1973
oral/rat lowest published toxic dose: 1500 mg/kg/8W- continuousKidney, Ureter, and Bladder: Changes in kidney weight

Endocrine: Changes in spleen weight
JAFCAU 21,324,1973

Reviews

OrganizationStandardReference
International Agency for Research on Cancer (IARC)Cancer Review:Animal Sufficient EvidenceIMEMDT 79,-,2000
International Agency for Research on Cancer (IARC)Cancer Review:Human Inadequate EvidenceIMEMDT 79,-,2000
International Agency for Research on Cancer (IARC)Cancer Review:Group 3IMEMDT 79,-,2000
TOXICOLOGY REVIEWENVRAL 7,243,1974
TOXICOLOGY REVIEWAIHAAP 39(6),A34,1978
TOXICOLOGY REVIEW85CVA2 5,250,1970
TOXICOLOGY REVIEWCNDQA8 14,49,1979
TOXICOLOGY REVIEWMUREAV 567,227,2004
TOXICOLOGY REVIEWMUREAV 627,59,2007
TOXICOLOGY REVIEWMUREAV 584,1,2005
TOXICOLOGY REVIEWMUREAV 654,114,2008
TOXICOLOGY REVIEWJTPAE7 17,69,2004
TOXICOLOGY REVIEWREPTED 26,1,2008
TOXICOLOGY REVIEWHTOPA* 1,501,2002
TOXICOLOGY REVIEWIMEMDT 79,659,
TOXICOLOGY REVIEWMUREAV 741,32,2012
TOXICOLOGY REVIEWMUREAV 760,1,2014
TOXICOLOGY REVIEWFCTOD7 55,596,2013
TOXICOLOGY REVIEWMUREAV 802,1,2016

Standards and Regulations

OrganizationStandardReference
Occupational Exposure Limit-FINLANDtime-weighted average 0.1 mg/m3, short term exposure limit 0.6 mg/m3, NOV2011
Occupational Exposure Limit-JAPAN2B carc, MAY2012
Occupational Exposure Limit-SWEDENGroup B Carcinogen, JUN2005
Occupational Exposure Limit-THE NETHERLANDSMAC-TGG 0.024 mg/m3, 2003

NIOSH Documentation and Surveillance

OrganizationStandardReference
National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Level TO ETHYLENE THIOUREA-airCarcinogen lowest feasible concentrationNIOSH* DHHS #92-100,1992
National Occupational Exposure Survey 1983Hazard Code 82079; Number of Industries 11; Total Number of Facilities 462; Number of Occupations 24; Total Number of Employees Exposed 10749; Total Number of Female Employees Exposed 1804
National Occupational Hazard Survey 1974Hazard Code 82079; Number of Industries 13; Total Number of Facilities 1100; Number of Occupations 39; Total Number of Employees Exposed 7475

Status in Federal Agencies

OrganizationReference
EPA GENETOX PROGRAM 1988, Inconclusive: Mammalian micronucleus
EPA GENETOX PROGRAM 1988, Negative: Cell transform.-SA7/SHE; Sperm morphology-mouse
EPA GENETOX PROGRAM 1988, Negative: TRP reversion
EPA GENETOX PROGRAM 1988, Positive: Carcinogenicity-mouse/rat; Rodent dominant lethal
EPA GENETOX PROGRAM 1988, Positive: Host-mediated assay; Histidine reversion-Ames test
EPA TSCA Section 8(b) CHEMICAL INVENTORY
EPA TSCA Section 8(d) unpublished health/safety studies
EPA TSCA TEST SUBMISSION (TSCATS) DATA BASE, JANUARY 2001
NCI Carcinogenesis Studies (feed);clear evidence:mouse,rat
NIOSH Analytical Method, 1994: Ethylene thiourea, 5011
NIOSH CURRENT INTELLIGENCE BULLETIN 22, 1978
NTP 11th Report on Carcinogens,2004:Reasonably anticipated to be a human carcinogen
On EPA IRIS database
OSHA ANALYTICAL METHOD #95
TOP