Nitrogen oxide

RTECS #

QX1350000

CAS #

10024-97-2
See: NMAM or OSHA Methods

Updated

December 2018

Molecular Weight

44.02

Molecular Formula

N₂O

Synonyms

Dinitrogen monoxide
Factitious air
Hyponitrous acid anhydride
Laughing gas
Nitrous oxide
Nitrous oxide (ACGIH:OSHA)

Mutation Data and Reference

System Test	Route/Organism/Tissue	Dose	Reference
DNA inhibition	inhalation/human	50 pph/24H	LANCAO 2,339,1978
DNA inhibition	inhalation/rat	75000 ppm/24H	AACRAT 62,738,1983
micronucleus test	inhalation/human	1000 µg/L/18Y- intermittent	MUREAV 581,1,2005
other mutation test systems	inhalation/rat	50 pph/2D-continuous	TCMUD8 8,107,1988
sex chromosome loss and nondisjunction	inhalation/Drosophila melanogaster	99 pph/6M-continuous	ENVRAL 7,286,1974

Reproductive Effects Data and References

Route/Organism	Dose	Effect	Reference
inhalation/rat	5 pph/4H (6-15D pregnant)	Reproductive: Effects on newborn: Behavioral	TJADAB 31,6B,1985
inhalation/rat	20 pph/8H (28D male)	Reproductive: Paternal effects: Testes, epididymis, sperm duct	ANESAV 44,104,1976
inhalation/rat	50 pph/24H (8-11D pregnant)	Reproductive: Specific developmental abnormalities: Central nervous system Reproductive: Specific developmental abnormalities: Cardiovascular (circulatory) system Reproductive: Specific developmental abnormalities: Urogenital system	NATUAS 214,146,1967
inhalation/rat	50 ppm/6H (30D male)	Reproductive: Effects on newborn: Live birth index (Litter size (e.g., # fetuses per litter; measured after birth) Reproductive: Effects on newborn: Growth statistics (e.g., reduced weight gain)	ANASAB 38,319,1983
inhalation/rat	1 pph/8H (1-21D pregnant)	Reproductive: Effects on embryo or fetus: Extra embryonic structures (e.g., placenta, umbilical cord) Reproductive: Effects on embryo or fetus: Fetal death	ANESAV 48,11,1978
inhalation/rat	50 pph/4H (14D pregnant)	Reproductive: Effects on newborn: Biochemical and metabolic	DPTHDL 8,43,1985
inhalation/mouse	75 pph/6H (14D pregnant)	Reproductive: Effects on embryo or fetus: Cytological changes (including somatic cell genetic material)	TJADAB 32,26A,1985
inhalation/mouse	5000 ppm/4H (14D pregnant)	Reproductive: Effects on newborn: Behavioral	NTOTDY 8,189,1986
inhalation/hamster	90 pph/24H (10D pregnant)	Reproductive: Effects on fertility: Post- implantation mortality (e.g., dead and/or resorbed implants per total number of implants)	CJPPA3 57,1229,1979
inhalation/hamster	95 pph/24H (7D pregnant)	Reproductive: Effects on embryo or fetus: Fetotoxicity (except death, e.g., stunted fetus)	CJPPA3 57,1229,1979
inhalation/rat	0.1 pph (1-19D pregnant)	Reproductive: Effects on embryo or fetus: Fetal death Reproductive: Other developmental abnormalities	VCVN5* -,31,1989
subcutaneous/rat	3 gm/kg (8D pregnant)	Reproductive: Effects on fertility: Post- implantation mortality (e.g., dead and/or resorbed implants per total number of implants) Reproductive: Other effects to embryo or fetus Reproductive: Specific developmental abnormalities: Musculoskeletal system	TJADAB 43,151,1991
subcutaneous/rat	3 gm/kg (8D pregnant)	Reproductive: Specific developmental abnormalities: Cardiovascular (circulatory) system	TJADAB 43,151,1991

Acute Toxicity Data and References

Route/Organism	Dose	Effect	Reference
inhalation/Dog	lowest published toxic concentration: 47 pph/1H	Blood: Other changes	AANEAB 46,699,2002
inhalation/human	lowest published toxic concentration: 24 mg/kg/2H	Behavioral: General anesthetic Cardiac: Pulse rate decreased with fall in BP Nutritional and Gross Metabolic: Body temperature decrease	BJANAD 35,631,1963
inhalation/mouse	lowest published toxic concentration: 25 pph/5M	Behavioral: Analgesia	JPETAB 306,484,2003
inhalation/rat	lowest published toxic concentration: 60 pph/90M	Nutritional and Gross Metabolic: Body temperature decrease	PSCHDL 191,233,2007
inhalation/rat	lowest published toxic concentration: 60 mg/m³	Liver: Multiple effects	VCVN5* -,31,1993

Other Multiple Dose Data and References

Route/Organism	Dose	Effect	Reference
inhalation/hamster	lowest published toxic concentration: 90 mg/m³/24H/10W- continuous	Lung, Thorax, or Respiration: Acute pulmonary edema Lung, Thorax, or Respiration: Changes in lung weight Related to Chronic Data: Death in the "MULTIPLE DOSE" data type field	VCVN5* -,31,1989
inhalation/mouse	lowest published toxic concentration: 50 ppm/6H/13W- intermittent	Liver: Changes in liver weight Blood: Changes in leukocyte (WBC) count	TIHEEC 6,57,1990
inhalation/rat	lowest published toxic concentration: 60 pph/90M/4D- intermittent	Behavioral: Tolerance	PSCHDL 191,233,2007
inhalation/rat	lowest published toxic concentration: 60 pph/90M/5D- intermittent	Behavioral: Tolerance Nutritional and Gross Metabolic: Body temperature increase	PSCHDL 191,233,2007
inhalation/rat	lowest published toxic concentration: 60 pph/90M/5D- intermittent	Behavioral: Tolerance	PSCHDL 191,233,2007
inhalation/woman	lowest published toxic concentration: 59 ppm/5Y- intermittent	Peripheral Nerve and Sensation: Sensory syndrome diagnostic of central lesion	NRTXDN 26,193,2005

Reviews

Organization	Standard	Reference
American Conference of Governmental Industrial Hygienists (ACGIH)	Threshold Limit Value-time-weighted average 50 ppm	DTLVS* TLV/BEI,2013
American Conference of Governmental Industrial Hygienists (ACGIH)	Threshold Limit Value-Not classifiable as a human carcinogen	DTLVS* TLV/BEI,2013
International Agency for Research on Cancer (IARC)	Cancer Review:Animal Inadequate Evidence	IMSUDL 7,93,1987
TOXICOLOGY REVIEW		CLPTAT 8,91,1967
TOXICOLOGY REVIEW		AACRAT 57,328,1978
TOXICOLOGY REVIEW		XPHBAO 272,1,1941
TOXICOLOGY REVIEW		TPHSDY 24,55,2003
TOXICOLOGY REVIEW		TPHSDY 24,609,2003
TOXICOLOGY REVIEW		ENTOX* -,251,2005
TOXICOLOGY REVIEW		HUTOX* -,661,1996
TOXICOLOGY REVIEW		HUTOX* -,577,1996
TOXICOLOGY REVIEW		MUREAV 674,62,2009
TOXICOLOGY REVIEW		BLREV* 3,71,1989
TOXICOLOGY REVIEW		NCLNA* 16,503,1998
TOXICOLOGY REVIEW		NEUCL* 23,377,2005
TOXICOLOGY REVIEW		NBREV* 5,1,1981
TOXICOLOGY REVIEW		PRESR* 7,123,2006
TOXICOLOGY REVIEW		NTAPM* -,617,1995
TOXICOLOGY REVIEW		NTAPM* -,629,1995
TOXICOLOGY REVIEW		MUTAEX 26,43,2011
TOXICOLOGY REVIEW		MUREAV 717,46,2011
TOXICOLOGY REVIEW		NRTXDN 33,605,2012
TOXICOLOGY REVIEW		MUREAV 733,21,2012
TOXICOLOGY REVIEW		MUTAEX 30,459,2015
TOXICOLOGY REVIEW		MUREAV 770,26,2016
TOXICOLOGY REVIEW		NETEEC 60,102,2017
TOXICOLOGY REVIEW		NETEEC 60,95,2017

Standards and Regulations

Organization	Standard	Reference
Mine Safety and Health Administration (MSHA) STANDARD	ASPHYXIANTS/GASES	DTLWS* 3,25,1973
Occupational Exposure Limit IN ARGENTINA, BULGARIA, COLOMBIA, JORDAN check ACGIH TLV;
Occupational Exposure Limit IN SINGAPORE, VIETNAM check ACGIH TLV
Occupational Exposure Limit-AUSTRALIA	time-weighted average 25 ppm (45 mg/m³), JUL2008
Occupational Exposure Limit-AUSTRIA	MAK-TMW 100 ppm (180 mg/m³);KZW 400 ppm (720 mg/m³), 2007
Occupational Exposure Limit-BELGIUM	time-weighted average 50 ppm (91 mg/m³), MAR2002
Occupational Exposure Limit-DENMARK	time-weighted average 50 ppm (90 mg/m³), MAY2011
Occupational Exposure Limit-FINLAND	time-weighted average 100 ppm (180 mg/m³), NOV2011
Occupational Exposure Limit-GERMANY	MAK 100 ppm (180 mg/m³), 2011
Occupational Exposure Limit-HUNGARY	time-weighted average 180 mg/m³, short term exposure limit 720 mg/m³, SEP2000
Occupational Exposure Limit-ICELAND	time-weighted average 50 ppm (90 mg/m³), NOV2011
Occupational Exposure Limit-NEW ZEALAND	time-weighted average 25 ppm (45 mg/m³), JAN2002
Occupational Exposure Limit-NORWAY	time-weighted average 100 ppm (180 mg/m³), JAN1999
Occupational Exposure Limit-PERU	time-weighted average 50 ppm (90 mg/m³), JUL2005
Occupational Exposure Limit-SWEDEN	time-weighted average 100 ppm (180 mg/m³);short term exposure limit 500 ppm (900 mg/m³), JUN2005
Occupational Exposure Limit-SWITZERLAND	MAK-week 100 ppm (182 mg/m³), KZG-week 200 ppm (364 mg/m³), JAN2011
Occupational Exposure Limit-THE NETHERLANDS	MAC-TGG 152 mg/m³, 2003
Occupational Exposure Limit-UNITED KINGDOM	time-weighted average 100 ppm (183 mg/m³), OCT2007
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Construction)	simple asphyxiant-inert gases and vapors	CFRGBR 29,1926.55,1994
Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (Shipyards)	Simple asphyxiant - inert gas and vapor	CFRGBR 29,1915.1000,1993

NIOSH Documentation and Surveillance

Organization	Standard	Reference
National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Level TO NITROUS OXIDE-air	time-weighted average 25 ppm for duration of exposure	NIOSH* DHHS #92-100,1992
National Occupational Exposure Survey 1983	Hazard Code 51118; Number of Industries 25; Total Number of Facilities 5145; Number of Occupations 34; Total Number of Employees Exposed 112585; Total Number of Female Employees Exposed 74465
National Occupational Hazard Survey 1974	Hazard Code 51118; Number of Industries 45; Total Number of Facilities 5599; Number of Occupations 36; Total Number of Employees Exposed 113333

Status in Federal Agencies

Organization	Reference
EPA GENETOX PROGRAM 1988, Inconclusive: Carcinogenicity-mouse/rat
EPA GENETOX PROGRAM 1988, Negative: Sperm morphology-mouse
EPA GENETOX PROGRAM 1988, Positive: V79 cell culture-gene mutation
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: Nitrous oxide, 6600
OSHA ANALYTICAL METHOD #ID166

Page last reviewed: November 16, 2018

Content source: National Institute for Occupational Safety and Health