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Chlorine dioxide

Synonyms & Trade Names
Chlorine oxide, Chlorine peroxide
CAS No.
10049-04-4
RTECS No.
DOT ID & Guide
9191 143(hydrate, frozen)
Formula
ClO₂
Conversion
1 ppm = 2.76 mg/m3
IDLH
5 ppm
See: 10049044
Exposure Limits
NIOSH REL
TWA 0.1 ppm (0.3 mg/m3) ST 0.3 ppm (0.9 mg/m3)
OSHA PEL
TWA 0.1 ppm (0.3 mg/m3) See Appendix G
Measurement Methods
OSHA ID126SGX , ID202
See: NMAM or OSHA Methods
Physical Description
Yellow to red gas or a red-brown liquid (below 52°F) with an unpleasant odor similar to chlorine and nitric acid.
Molecular Weight
67.5
Boiling Point
52°F
Freezing Point
-74°F
Solubility
(77°F): 0.3%
Vapor Pressure
>1 atm
Ionization Potential
10.36 eV
Specific Gravity
1.6 (Liquid at 32°F)
Flash Point
NA (Gas) ? (Liquid)
Upper Explosive Limit
?
Lower Explosive Limit
?
Relative Gas Density
2.33
Flammable Gas/Combustible Liquid
Incompatibilities & Reactivities
Organic materials, heat, phosphorus, potassium hydroxide, sulfur, mercury, carbon monoxide [Note: Unstable in light. A powerful oxidizer.]
Exposure Routes
inhalation, ingestion (liquid), skin and/or eye contact
Symptoms
irritation eyes, nose, throat; cough, wheezing, bronchitis, pulmonary edema; chronic bronchitis
Target Organs
Eyes, respiratory system
Personal Protection/Sanitation
(See protection codes)
Skin:Prevent skin contact (liquid)
Eyes:Prevent eye contact (liquid)
Wash skin:When contaminated (liquid)
Remove:When wet (flammable)
Change:No recommendation
Provide:Eyewash (liquid), Quick drench (liquid)
First Aid
(See procedures)
Eye:Irrigate immediately (liquid)
Skin:Soap wash immediately (liquid)
Breathing:Respiratory support
Swallow:Medical attention immediately (liquid)
Respirator Recommendations

NIOSH/OSHA

Up to 1 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 2.5 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£

Up to 5 ppm:
(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: 0127   MEDICAL TESTS: 0045
Page last reviewed: October 30, 2019