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Toluene, o-nitro-

RTECS #
XT3150000
CAS #
88-72-2; 57158-05-1
See: NMAM or OSHA Methods
Updated
March 2019
Molecular Weight
137.15
Molecular Formula
C7H7NO2
Synonyms
1-Methyl-2-nitrobenzene
2-Methylnitrobenzene
2-Nitrotoluene
2-Nitrotoluol
Benzene, 1-methyl-2-nitro- (9CI)
Nitrotoluene, ortho-
o-Methylnitrobenzene
o-Nitrotoluene
o-Nitrotoluene (ACGIH:OSHA)
ONT
ortho-Nitrotoluol

Mutation Data and Reference

System TestRoute/Organism/TissueDoseReference
DNA adductoral/rat150 mg/kgCBINA8 51,131,1984
sister chromatid exchangeovary/hamster355 mg/LEMMUEG 10(Suppl 10),1,1987
Unscheduled DNA Synthesisoral/rat200 mg/kgCNREA8 43,2836,1983
Unscheduled DNA Synthesisliver/rat500 µg/LEMMUEG 26,147,1995

Reproductive Effects Data and References

Route/OrganismDoseEffectReference
oral/rat 32123 mg/kg (13W male)Reproductive: Paternal effects: Spermatogenesis (including genetic material, sperm morphology, motility, and count)

Reproductive: Paternal effects: Testes, epididymis, sperm duct
NTPTR* NIH-93-3346
oral/rat 69154 mg/kg (13W prior to copulation)Reproductive: Maternal effects: Menstrual cycle changes or disordersNTPTR* NIH-93-3346
oral/mouse 140 gm/kg (13W male)Reproductive: Paternal effects: Spermatogenesis (including genetic material, sperm morphology, motility, and count)NTPTR* NIH-93-3346

Tumorigenic Data and References

Route/OrganismDoseEffectReference
oral/mouse lowest published toxic dose: 109.5 gm/kg/2Y- continuousTumorigenic: Equivocal tumorigenic agent by RTECS criteria

Vascular: Tumors

Gastrointestinal: Colon tumors
TXCYAC 183,221,2003
oral/mouse lowest published toxic dose: 219 gm/kg/2Y- continuousTumorigenic: Equivocal tumorigenic agent by RTECS criteria

Gastrointestinal: Colon tumors

Liver: Tumors
TXCYAC 183,221,2003
oral/rat lowest published toxic dose: 32.12 gm/kg/13W- intermittentTumorigenic: Carcinogenic by RTECS criteria

Reproductive: Other reproductive system tumors
TOXID9 72,143,2003
oral/rat lowest published toxic dose: 26.57 gm/kg/13W- intermittentTumorigenic: Carcinogenic by RTECS criteria

Liver: Tumors
TOXID9 72,143,2003
oral/rat lowest published toxic dose: 54600 mg/kg/26W- continuousTumorigenic: Neoplastic by RTECS criteria

Reproductive: Other reproductive system tumors
NTPTR* NIH-96-3936
oral/rat lowest published toxic dose: 27.4 gm/kg/2Y- continuousTumorigenic: Equivocal tumorigenic agent by RTECS criteria

Skin and Appendages: Tumors
TXCYAC 183,221,2003
oral/rat lowest published toxic dose: 87.6 gm/kg/2Y- continuousTumorigenic: Equivocal tumorigenic agent by RTECS criteria

Liver: Tumors

Skin and Appendages: Tumors
TXCYAC 183,221,2003
oral/rat lowest published toxic dose: 10.1 gm/kg/12W- continuousTumorigenic: Equivocal tumorigenic agent by RTECS criteria

Liver: Tumors

Skin and Appendages: Tumors
TXCYAC 183,221,2003
oral/rat lowest published toxic dose: 25.2 gm/kg/12W- continuousTumorigenic: Equivocal tumorigenic agent by RTECS criteria

Lung, Thorax, or Respiration: Tumors

Liver: Tumors
TXCYAC 183,221,2003
oral/rat lowest published toxic dose: 45.6 gm/kg/2Y- continuousTumorigenic: Equivocal tumorigenic agent by RTECS criteria

Skin and Appendages: Tumors
TXCYAC 183,221,2003
oral/rat lowest published toxic dose: 182.5 gm/kg/2Y- continuousTumorigenic: Equivocal tumorigenic agent by RTECS criteria

Liver: Tumors

Skin and Appendages: Tumors
TXCYAC 183,221,2003

Acute Toxicity Data and References

Route/OrganismDoseEffectReference
inhalation/mouse lethal concentration (50 percent kill): 328 mg/m3Brain and Coverings: Recordings from specific areas of CNS

Liver: Fatty liver degeneration

Blood: Methemoglobinemia- Carboxhemoglobinemia
GTPZAB 22(7),52,1978
inhalation/rat lethal concentration (50 percent kill): 790 mg/m3Brain and Coverings: Recordings from specific areas of CNS

Liver: Fatty liver degeneration

Blood: Methemoglobinemia- Carboxhemoglobinemia
GTPZAB 22(7),52,1978
oral/mouse lethal dose (50 percent kill): 970 mg/kgGTPZAB 25(8),50,1981
oral/rabbit lethal dose (50 percent kill): 1750 mg/kgBrain and Coverings: Recordings from specific areas of CNS

Liver: Fatty liver degeneration

Blood: Methemoglobinemia- Carboxhemoglobinemia
GTPZAB 22(7),52,1978
oral/rat lethal dose (50 percent kill): 891 mg/kgHPV005 -,-,2006

Other Multiple Dose Data and References

Route/OrganismDoseEffectReference
oral/mouse lowest published toxic dose: 70343 mg/kg/13W- continuousOlfaction: Change in olfactory nerve

Liver: Changes in liver weight

Kidney, Ureter, and Bladder: Changes in bladder weight
NTPTR* NIH-93-3346
oral/mouse lowest published toxic dose: 8400 mg/kg/14D- intermittentBlood: Changes in other cell count (unspecified)DCTODJ 17,359,1994
oral/mouse lowest published toxic dose: 6825 mg/kg/13W- continuousNutritional and Gross Metabolic: Weight loss or decreased weight gainTXCYAC 183,221,2003
oral/mouse lowest published toxic dose: 33600 mg/kg/8W- continuousNutritional and Gross Metabolic: Weight loss or decreased weight gainTXCYAC 183,221,2003
oral/mouse lowest published toxic dose: 109500 mg/kg/2Y- continuousGastrointestinal: Other changes

Gastrointestinal: Tumors
CRNGDP 25,605,2004
oral/mouse lowest published toxic dose: 840 mg/kg/2W- continuousLiver: Other changesCRNGDP 26,689,2005
oral/rat lowest published toxic dose: 32123 mg/kg/13W- continuousLiver: Changes in liver weight

Blood: Changes in platelet count

Related to Chronic Data: Changes in testicular weight
NTPTR* NIH-93-3346
oral/rat lowest published toxic dose: 54600 mg/kg/26W- continuousLiver: Changes in liver weight

Nutritional and Gross Metabolic: Weight loss or decreased weight gain

Related to Chronic Data: Changes in testicular weight
NTPTR* NIH-96-3936
oral/rat lowest published toxic dose: 3937.5 mg/kg/15W- continuousNutritional and Gross Metabolic: Weight loss or decreased weight gainTXCYAC 183,221,2003
oral/rat lowest published toxic dose: 21000 mg/kg/30W- continuousNutritional and Gross Metabolic: Weight loss or decreased weight gainTXCYAC 183,221,2003
oral/rat lowest published toxic dose: 36.4 gm/kg/26W- intermittentBlood: Changes in spleenTOXID9 72,143,2003
oral/rat lowest published toxic dose: 924 mg/kg/3W- intermittentBlood: Methemoglobinemia- CarboxhemoglobinemiaTOXID9 72,143,2003

Reviews

OrganizationStandardReference
American Conference of Governmental Industrial Hygienists (ACGIH)Threshold Limit Value-time-weighted average 2 ppm (skin)DTLVS* TLV/BEI,2013
International Agency for Research on Cancer (IARC)Cancer Review:Animal Limited EvidenceIMEMDT 65,409,1996
International Agency for Research on Cancer (IARC)Cancer Review:Animal Sufficient EvidenceIMEMDT 101,112,2013
International Agency for Research on Cancer (IARC)Cancer Review:Human Inadequate EvidenceIMEMDT 65,409,1996
International Agency for Research on Cancer (IARC)Cancer Review:Human Inadequate EvidenceIMEMDT 101,111,2013
International Agency for Research on Cancer (IARC)Cancer Review:Group 3IMEMDT 65,409,1996
International Agency for Research on Cancer (IARC)Cancer Review:Group 2AIMEMDT 101,112,2013
TOXICOLOGY REVIEWMUREAV 588,88,2005
TOXICOLOGY REVIEWBCLPT* 96,131,2005
TOXICOLOGY REVIEWHETOEA 25,413,2006
TOXICOLOGY REVIEWMUREAV 659,248,2008
TOXICOLOGY REVIEWMUTAEX 23,271,2008
TOXICOLOGY REVIEWMUREAV 721,27,2011
TOXICOLOGY REVIEWMUREAV 751,49,2012
TOXICOLOGY REVIEWRTOPDW 53,134,2009
TOXICOLOGY REVIEWRTOPDW 60,120,2011

Standards and Regulations

OrganizationStandardReference
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 2 ppm (11 mg/m3), JUL2008
Occupational Exposure Limit-AUSTRIATRK-TMW 0.5 mg/m3;KZW 2 mg/m3, skin, 2007
Occupational Exposure Limit-BELGIUMtime-weighted average 2 ppm (11 mg/m3), Skin, MAR2002
Occupational Exposure Limit-DENMARKtime-weighted average 2 ppm (12 mg/m3), skin, MAY2011
Occupational Exposure Limit-ICELANDtime-weighted average 2 ppm (12 mg/m3), skin, NOV2011
Occupational Exposure Limit-KOREAtime-weighted average 2 ppm (11 mg/m3), skin, 2006
Occupational Exposure Limit-MEXICOtime-weighted average 5 ppm (30 mg/m3);short term exposure limit 10 ppm (60 mg/m3), 2004
Occupational Exposure Limit-NEW ZEALANDtime-weighted average 2 ppm (11 mg/m3), skin, JAN2002
Occupational Exposure Limit-NORWAYtime-weighted average 1 ppm (5.5 mg/m3), JAN1999
Occupational Exposure Limit-PERUtime-weighted average 2 ppm (11 mg/m3), JUL2005
Occupational Exposure Limit-SWEDENtime-weighted average 1 ppm (6 mg/m3);short term exposure limit 2 ppm (11 mg/m3), Skin, JUN2005
Occupational Exposure Limit-SWITZERLANDcarc 2, JAN2011
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Construction)8H time-weighted average 5 ppm (30 mg/m3) (skin)CFRGBR 29,1926.55,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Federal Contractors)8H time-weighted average 5 ppm (30 mg/m3) (skin)CFRGBR 41,50-204.50,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (General Industry)8H time-weighted average 5 ppm (30 mg/m3) (skin)CFRGBR 29,1910.1000,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Shipyards)8H time-weighted average 5 ppm (30 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 o-NITROTOLUENE-air10H time-weighted average 2 ppm (Sk)NIOSH* DHHS #92-100,1992
National Occupational Hazard Survey 1974Hazard Code 81910; Number of Industries 2; Total Number of Facilities 20; Number of Occupations 2; Total Number of Employees Exposed 285

Status in Federal Agencies

OrganizationReference
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
NTP 14th Report on Carcinogens,2016:Reasonably anticipated to be human carcinogen
NTP Carcinogenesis studies; on test (two year studies), October 2000
NTP Toxicity studies, RPT# TOX-23, October 2000
NTP Toxicity studies, RPT# TOX-44, October 2000
Page last reviewed: November 16, 2018