NIOSH logo and tagline

Nitric acid

RTECS #
QU5775000
CAS #
7697-37-2
See: NMAM or OSHA Methods
Updated
December 2018
Molecular Weight
63.02
Molecular Formula
HNO3
Synonyms
Acide nitrique (French)
Acido nitrico (Italian)
Aqua fortis
Azotic acid
Azotowy kwas (Polish)
Hydrogen nitrate
Kyselina dusicne (Czech)
Nitric acid (ACGIH:OSHA)
Salpetersaure (German)
Salpeterzuuroplossingen (Dutch)

Reproductive Effects Data and References

Route/OrganismDoseEffectReference
oral/rat 21150 mg/kg (1-21D pregnant)Reproductive: Effects on embryo or fetus: Fetotoxicity (except death, e.g., stunted fetus)ZHYGAM 29,667,1983
oral/rat 2345 mg/kg (18D pregnant)Reproductive: Effects on newborn: Biochemical and metabolicZHYGAM 29,667,1983

Acute Toxicity Data and References

Route/OrganismDoseEffectReference
In Vitro/Human, liver tumor Inhibitor Concentration (50 percent kill): 40 mmol/L/24HIn Vitro Toxicity Studies: Cell protein synthesisTIVIEQ 3,189,1989
inhalation/cat lowest published toxic concentration: 300 mg/m3/2HLung, Thorax, or Respiration: Acute pulmonary edemaVCVN5* -,45,1993
inhalation/cat Lowest published lethal concentration: 500 mg/m3VCVN5* -,45,1993
inhalation/rat lethal concentration (50 percent kill): 260 mg/m3/30MVCVN5* -,45,1993
inhalation/rat lethal concentration (50 percent kill): 130 mg/m3/4HVCVN5* -,45,1993
inhalation/rat lowest published toxic concentration: 460 ppm/1HNutritional and Gross Metabolic: Weight loss or decreased weight gainTOXID9 44,302,2005
inhalation/rat Lowest published lethal concentration: 919 ppm/1HTOXID9 44,302,2005
oral/human lowest published lethal dose: 430 mg/kgYAKUD5 22,651,1980
skin/rat lowest published toxic dose: 150 mL/kgBlood: Methemoglobinemia- CarboxhemoglobinemiaVCVN5* -,46,1993
unreported route/man lowest published lethal dose: 110 mg/kg85DCAI 2,73,1970

Other Multiple Dose Data and References

Route/OrganismDoseEffectReference
inhalation/rat lowest published toxic concentration: 1071 µg/m3/24H/84D- continuousBehavioral: Muscle contraction or spasticity

Kidney, Ureter, and Bladder: Other changes in urine composition

Biochemical: Enzyme inhibition, induction, or change in blood or tissue levels: True cholinesterase
GISAAA 38(3),6,1973
inhalation/rat lowest published toxic concentration: 50 µg/m3/4H/3D- intermittentLung, Thorax, or Respiration: Respiratory depressionINHTE5 8,595,1996

Reviews

OrganizationStandardReference
American Conference of Governmental Industrial Hygienists (ACGIH)Threshold Limit Value-time-weighted average 2 ppm;short term exposure limit 4 ppmDTLVS* TLV/BEI,2013
TOXICOLOGY REVIEWANAEA3 35,165,1975
TOXICOLOGY REVIEWARTODN 39,299,1978
TOXICOLOGY REVIEWNCLNA* 16,107,1998
TOXICOLOGY REVIEWRTOPDW 54,247,2009

Standards and Regulations

OrganizationStandardReference
Mine Safety and Health Administration (MSHA) STANDARD-airtime-weighted average 2 ppm (5 mg/m3)DTLVS* 3,181,1971
Occupational Exposure Limit IN ARGENTINA, BULGARIA, COLOMBIA, JORDAN check ACGIH TLV;
Occupational Exposure Limit IN SINGAPORE, VIETNAM check ACGIH TLV
Occupational Exposure Limit-ARAB Republic of Egypttime-weighted average 2 ppm (5 mg/m3), JAN1993
Occupational Exposure Limit-AUSTRALIAtime-weighted average 2 ppm (5.2 mg/m3), short term exposure limit 4 ppm (10 mg/m3), JUL2008
Occupational Exposure Limit-AUSTRIAMAK-KZW 1 ppm (2.6 mg/m3), 2007
Occupational Exposure Limit-BELGIUMshort term exposure limit 1 ppm (2.6 mg/m3), MAR2002
Occupational Exposure Limit-DENMARKtime-weighted average 1 ppm (2.6 mg/m3), MAY2011
Occupational Exposure Limit-ECshort term exposure limit 2.6 mg/m3 (1 ppm), FEB2006
Occupational Exposure Limit-FINLANDtime-weighted average 0.5 ppm (1.3 mg/m3), short term exposure limit 1 ppm (2.6 mg/m3), NOV2011
Occupational Exposure Limit-FRANCEVME 2 ppm (5 mg/m3), VLE 4 ppm (10 mg/m3), FEB2006
Occupational Exposure Limit-HUNGARYtime-weighted average 5 mg/m3, short term exposure limit 5 mg/m3, SEP2000
Occupational Exposure Limit-ICELANDshort term exposure limit 1 ppm (2.6 mg/m3), NOV2011
Occupational Exposure Limit-JAPANOccupational Exposure Limit 2 ppm (5.2 mg/m3), MAY2012
Occupational Exposure Limit-KOREAtime-weighted average 2 ppm (5 mg/m3), short term exposure limit 4 ppm (10 mg/m3), 2006
Occupational Exposure Limit-MEXICOtime-weighted average 2 ppm (5 mg/m3);short term exposure limit 4 ppm (10 mg/m3), 2004
Occupational Exposure Limit-NEW ZEALANDtime-weighted average 2 ppm (5.2 mg/m3), short term exposure limit 4 ppm (10 mg/m3), JAN2002
Occupational Exposure Limit-NORWAYtime-weighted average 2 ppm (5 mg/m3), JAN1999
Occupational Exposure Limit-PERUtime-weighted average 2 ppm (5.2 mg/m3); short term exposure limit 4 ppm (10.4 mg/m3), JUL2005
Occupational Exposure Limit-POLANDMAC(time-weighted average) 5 mg/m3, MAC(short term exposure limit) 10 mg/m3, JAN1999
Occupational Exposure Limit-RUSSIAshort term exposure limit 2 mg/m3, Skin, JUN2003
Occupational Exposure Limit-SWEDENtime-weighted average 2 ppm (5 mg/m3);short term exposure limit 5 ppm (13 mg/m3), JUN2005
Occupational Exposure Limit-SWITZERLANDceiling concentration 2 ppm (5 mg/m3), JAN2011
Occupational Exposure Limit-THAILANDtime-weighted average 2 ppm (5 mg/m3), JAN1993
Occupational Exposure Limit-THE PHILIPPINEStime-weighted average 2 ppm (5 mg/m3), JAN1993
Occupational Exposure Limit-TURKEYtime-weighted average 2 ppm (5 mg/m3), JAN1993
Occupational Exposure Limit-UNITED KINGDOMshort term exposure limit 1 ppm (2.6 mg/m3), OCT2007
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Construction)8H time-weighted average 2 ppm (5 mg/m3)CFRGBR 29,1926.55,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Federal Contractors)8H time-weighted average 2 ppm (5 mg/m3)CFRGBR 41,50-204.50,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (General Industry)8H time-weighted average 2 ppm (5 mg/m3)CFRGBR 29,1910.1000,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Shipyards)8H time-weighted average 2 ppm (5 mg/m3)CFRGBR 29,1915.1000,1993

NIOSH Documentation and Surveillance

OrganizationStandardReference
National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Level TO NITRIC ACID-air10H time-weighted average 2 ppm;short term exposure limit 4 ppmNIOSH* DHHS #92-100,1992
National Occupational Exposure Survey 1983Hazard Code 50742; Number of Industries 201; Total Number of Facilities 18239; Number of Occupations 120; Total Number of Employees Exposed 297627; Total Number of Female Employees Exposed 76316
National Occupational Hazard Survey 1974Hazard Code 50742; Number of Industries 197; Total Number of Facilities 18088; Number of Occupations 101; Total Number of Employees Exposed 132401

Status in Federal Agencies

OrganizationReference
EPA GENETOX PROGRAM 1988, Negative: Cell transform.-SA7/SHE
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
NIOSH Analytical Method, 1994: Acids, inorganic, 7903
OSHA ANALYTICAL METHOD #ID-127
Page last reviewed: November 16, 2018