NIOSH logo and tagline

Chlorine

Synonyms & Trade Names
Molecular chlorine
CAS No.
7782-50-5
RTECS No.
DOT ID & Guide
1017 124
Formula
Cl₂
Conversion
1 ppm = 2.90 mg/m3
IDLH
10 ppm
See: 7782505
Exposure Limits
NIOSH REL
C 0.5 ppm (1.45 mg/m3) [15-minute]
OSHA PEL
C 1 ppm (3 mg/m3) See Appendix G
Measurement Methods
NIOSH 6011;
OSHA ID101 , ID126SGX
See: NMAM or OSHA Methods
Physical Description
Greenish-yellow gas with a pungent, irritating odor. [Note: Shipped as a liquefied compressed gas.]
Molecular Weight
70.9
Boiling Point
-29°F
Freezing Point
-150°F
Solubility
0.7%
Vapor Pressure
6.8 atm
Ionization Potential
11.48 eV
Flash Point
NA
Upper Explosive Limit
NA
Lower Explosive Limit
NA
Relative Gas Density
2.47
Nonflammable Gas, but a strong oxidizer.
Incompatibilities & Reactivities
Reacts explosively or forms explosive compounds with many common substances such as acetylene, ether, turpentine, ammonia, fuel gas, hydrogen & finely divided metals.
Exposure Routes
inhalation, skin and/or eye contact
Symptoms
Burning of eyes, nose, mouth; lacrimation (discharge of tears), rhinorrhea (discharge of thin nasal mucus); cough, choking, substernal (occurring beneath the sternum) pain; nausea, vomiting; headache, dizziness; syncope; pulmonary edema; pneumonitis; hypoxemia (reduced O2 in the blood); dermatitis; liquid: frostbite
Target Organs
Eyes, skin, respiratory 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:Respiratory support
Respirator Recommendations

NIOSH

Up to 5 ppm:
(APF = 10) Any chemical cartridge respirator with cartridge(s) providing protection against the compound of concern*
(APF = 10) Any supplied-air respirator*

Up to 10 ppm:
(APF = 25) Any supplied-air respirator operated in a continuous-flow mode*
(APF = 25) Any powered, air-purifying respirator with cartridge(s) providing protection against the compound of concern*
(APF = 50) Any chemical cartridge respirator with a full facepiece and cartridge(s) providing protection against the compound of concern
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern
(APF = 50) Any self-contained breathing apparatus with a full facepiece
(APF = 50) Any supplied-air respirator 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:
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern
Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

See also
INTRODUCTION   ICSC CARD: 0126   MEDICAL TESTS: 0044
Page last reviewed: October 30, 2019