NITROUS OXIDE

Chemical Identification
Chemical Identification
CAS # 10024-97-2
Formula
 

N₂O

Synonyms
 

dinitrogen monoxide; hyponitrous acid anhydride; laughing gas; nitrogen oxide

Physical Properties
Physical Properties
Physical description Colorless gas with a slightly sweet odor.
Boiling point -127°F Molecular weight 44.0
Freezing point/melting point 132°F Vapor pressure 51.3 atm
Flash point Vapor density 1.53
Specific gravity 1.266 at -128.2°F Ionization potential 12.89 eV
Lower explosive limit (LEL) Upper explosive limit (UEL)
NFPA health rating NFPA fire rating
NFPA reactivity rating NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs
Monitoring Methods Used by OSHA
Monitoring Methods Used by OSHA
Analyte code (IMIS no.) 1953
Sampling group
Sampler/Sampling media VAPOR TRAK® 8530 [KEM Medical Products 8530]
Sampling time*
 

Follow mfr instructions

Sampling volume (TWA)*
 

 

Sampling flow rate (TWA)*
 

 

Sampling volume (STEL/Peak/C)*
 

 

Sampling flow rate (STEL/Peak/C)*
 

 

Analytical method instruments IR
Method reference OSHA ID-166 (fully validated)
Notes
 

To obtain sampling and analytical error similar to that available with active sampling, knowledge of the atmospheric pressure and temperature are required, and these should be obtained using NIST-traceable devices. If that is not possible, temperature is assumed to be 22.2 °C, and the atmospheric pressure is estimated based on the elevation of the sampling location.

When estimates are used in place of traceable measurements the sampling and analytical error associated with passive sampling is substantially increased, and this makes it more difficult to demonstrate overexposures after considering the 95% lower confidence limit.

Special requirements
 

 

* All sampling instructions above are recommended guidelines for OSHA Compliance Safety and Health Officers (CSHOs), please see the corresponding OSHA method reference for complete details.

Wipe Method
Wipe Method
Sampler/Sampling media
 

 

Bulk Method
Bulk Method
 

 

On-Site Screening Techniques
On-Site Screening Techniques
Device
Model/Type
Sampling information
(see manufacturer instructions)
Exposure Limits
Exposure Limits
OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
NIOSH REL
Up to 10-hour TWA
(ST) STEL
(C) Ceiling
ACGIH TLV©
8-hour TWA
(ST) STEL
(C) Ceiling
CAL/OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
PEL-TWA
 

 

REL-TWA
 

25 ppm (46 mg/m³) [waste anesthetic gases only]

TLV-TWA
 

50 ppm [1986]

PEL-TWA
 

50 ppm (90 mg/m³)

PEL-STEL
 

 

REL-STEL
 

 

TLV-STEL
 

 

PEL-STEL
 

 

PEL-C
 

 

REL-C
 

 

TLV-C
 

 

PEL-C
 

 

Skin notation
 

N

Skin notation
 

N

Skin notation
 

N

Skin notation
 

N

Notes:

Nitrous oxide is classified as a simple asphyxiant and exposure is addressed in OSHA Construction and Maritime standards only.

For OSHA's construction regulations, see 29 CFR 1926.55 Table 1: [E] The limiting factor is the available oxygen which shall be at least 19.5% and be within the requirements addressing explosion in 29 CFR 1926.

For OSHA's maritime regulations, see 29 CFR 1915.1000 Table Z-Shipyards: [E] The limiting factor is the available oxygen which shall be at least 18% and be within the requirements addressing explosion in 29 CFR 1915, Subpart B.

Notes:
 

TWA IS CALCULATED OVER THE ACTUAL TIME EXPOSED

Notes:
 

 

Notes:
 

 

Health factors:  See NIH-NLM PubChem. IDLH
Carcinogenic classifications: TLV-A4 Notes:
 

 

AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:
 

 

Additional Resources and Literature References
Additional Resources and Literature References

NOAA: CAMEO Chemicals - Nitrous oxide

NIOSH: Pocket Guide to Chemical Hazards - Nitrous oxide

Literature References

 
  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Nitrous oxide. See annual publication for most recent information.
  • Pohanish, R.P. (editor): Nitrous Oxide. In, Sittig’s Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1748-1749.
  • Rowland, A.S., Baird, D.D., Shore, D.L., Weinberg, C.R., Savitz, D.A. and Wilcox, A.J.: Nitrous oxide and spontaneous abortion in female dental assistants. Am. J. Epidemiol. 141(6): 531-538, 1995.
  • Suruda, A.J. and McGlothlin, J.D.: Fatal abuse of nitrous oxide in the workplace. J. Occup. Med. 32(8): 682-684, 1990.
  • Weimann, J.: Toxicity of nitrous oxide. Best Pract. Res. Clin. Anaesthesiol. 17(1): 47-61, 2003.

Last Updated Date : 06/03/2022