NIOSH logo and tagline

Nitrous oxide

Synonyms & Trade Names
Dinitrogen monoxide, Hyponitrous acid anhydride, Laughing gas
CAS No.
10024-97-2
RTECS No.
DOT ID & Guide
1070 122
2201 122(refrigerated liquid)
Formula
N₂O
Conversion
1 ppm = 1.80 mg/m3
IDLH
N.D.
See: IDLH INDEX
Exposure Limits
NIOSH REL
TWA 25 ppm (46 mg/m3) (TWA over the time exposed) [*Note: REL for exposure to waste anesthetic gas.]
OSHA PEL
none
Measurement Methods
NIOSH 3800 , 6600;
OSHA ID166
See: NMAM or OSHA Methods
Physical Description
Colorless gas with a slightly sweet odor. [inhalation anesthetic] [Note: Shipped as a liquefied compressed gas.]
Molecular Weight
44.0
Boiling Point
-127°F
Freezing Point
-132°F
Solubility
(77°F): 0.1%
Vapor Pressure
51.3 atm
Ionization Potential
12.89 eV
Flash Point
NA
Upper Explosive Limit
NA
Lower Explosive Limit
NA
Relative Gas Density
1.53
Nonflammable Gas, but supports combustion at elevated temperatures.
Incompatibilities & Reactivities
Aluminum, boron, hydrazine, lithium hydride, phosphine, sodium
Exposure Routes
inhalation, skin and/or eye contact (liquid)
Symptoms
dyspnea (breathing difficulty); drowsiness, headache; asphyxia; reproductive effects; liquid: frostbite
Target Organs
respiratory system, central nervous system, reproductive system
Personal Protection/Sanitation
(See protection codes)
Skin:Frostbite
Eyes:Frostbite
Wash skin:No recommendation
Remove:No recommendation
Change:No recommendation
Provide:Frostbite wash
First Aid
(See procedures)
Eye:Frostbite
Skin:Frostbite
Breathing:Fresh air
Respirator Recommendations
See also
INTRODUCTION   ICSC CARD: 0067
Page last reviewed: October 30, 2019