Nitrous oxide
Synonyms & Trade Names
Dinitrogen monoxide, Hyponitrous acid anhydride, Laughing gasExposure Limits
NIOSH REL
TWA 25 ppm (46 mg/m3) (TWA over the time exposed) [*Note: REL for exposure to waste anesthetic gas.]OSHA PEL
nonePhysical Description
Colorless gas with a slightly sweet odor. [inhalation anesthetic] [Note: Shipped as a liquefied compressed gas.]Molecular Weight
44.0Boiling Point
-127°FFreezing Point
-132°FSolubility
(77°F): 0.1%Vapor Pressure
51.3 atmIonization Potential
12.89 eVFlash Point
NAUpper Exposive Limit
NALower Explosive Limit
NARelative Gas Density
1.53
Nonflammable Gas, but supports combustion at elevated temperatures.
Incompatibilities & Reactivities
Aluminum, boron, hydrazine, lithium hydride, phosphine, sodiumExposure Routes
inhalation, skin and/or eye contact (liquid)Symptoms
dyspnea (breathing difficulty); drowsiness, headache; asphyxia; reproductive effects; liquid: frostbiteTarget Organs
respiratory system, central nervous system, reproductive systemPersonal Protection/Sanitation
(See protection codes)Skin:Frostbite
Eyes:Frostbite
Wash skin:No recommendation
Remove:No recommendation
Change:No recommendation
Provide:Frostbite wash
Respirator Recommendations
Not available.
- Page last reviewed:April 11, 2016
- Page last updated:April 11, 2016
- Content source:
- National Institute for Occupational Safety and Health (NIOSH) Education and Information Division