NIOSH Pocket Guide to Chemical Hazards

Carbon dioxide

CAS 124-38-9


RTECS FF6400000
Synonyms & Trade Names
Carbonic acid gas, Dry ice [Note: Normal constituent of air (about 300 ppm)].
DOT ID & Guide
1013 120
1845 120 (dry ice)
2187 120 (liquid)


NIOSH REL: TWA 5000 ppm (9000 mg/m3) ST 30,000 ppm (54,000 mg/m3)
OSHA PEL†: TWA 5000 ppm (9000 mg/m3)
IDLH 40,000 ppm See: 124389 Conversion 1 ppm = 1.80 mg/m3
Physical Description
Colorless, odorless gas. [Note: Shipped as a liquefied compressed gas. Solid form is utilized as dry ice.]
MW: 44.0
BP: Sublimes
MLT: -109°F (Sublimes)
Sol(77°F): 0.2%
VP: 56.5 atm
IP: 13.77 eV
RGasD: 1.53

Fl.P: NA

Nonflammable Gas
Incompatibilities & Reactivities
Dusts of various metals, such as magnesium, zirconium, titanium, aluminum, chromium & manganese are ignitable and explosive when suspended in carbon dioxide. Forms carbonic acid in water.
Measurement Methods
NIOSH 6603; OSHA ID172
See: NMAM or OSHA Methods
Personal Protection & Sanitation (See protection)
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: Respiratory support

Important additional information about respirator selection
Respirator Recommendations NIOSH/OSHA
Up to 40,000 ppm:
(APF = 10) Any supplied-air respirator
(APF = 50) Any self-contained breathing apparatus with a full facepiece
Emergency or planned entry into unknown concentrations or IDLH conditions:
(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode
(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus
Escape: Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin and/or eye contact (liquid/solid)
Symptoms Headache, dizziness, restlessness, paresthesia; dyspnea (breathing difficulty); sweating, malaise (vague feeling of discomfort); increased heart rate, cardiac output, blood pressure; coma; asphyxia; convulsions; frostbite (liquid, dry ice)
Target Organs respiratory system, cardiovascular system
See also: INTRODUCTION   See ICSC CARD: 0021