# NIOSH Pocket Guide to Chemical Hazards
Benzoyl peroxide | CAS 94-36-0
(C6H5CO)2O2 | RTECS DM8575000
Synonyms & Trade Names Benzoperoxide, Dibenzoyl peroxide | DOT ID & Guide 2085 146 2087 146 2088 146 2089 146 2090 146
Exposure Limits | NIOSH REL: TWA 5 mg/m3
OSHA PEL: TWA 5 mg/m3
IDLH 1500 mg/m3 | Conversion
Physical Description Colorless to white crystals or a granular powder with a faint, benzaldehyde-like odor.
MW: 242.2 | BP: Decomposes explosively | MLT: 217°F | Sol: <1%
VP: <1 mmHg | IP: ? |  | Sp.Gr: 1.33
Fl.P: 176°F | UEL: ? | LEL: ? |
Combustible Solid (easily ignited and burns very rapidly).
Incompatibilities & Reactivities Combustible substances (wood, paper, etc.), acids, alkalis, alcohols, amines, ethers [Note: Containers may explode when heated. Extremely explosion-sensitive to shock, heat & friction.]
Measurement Methods NIOSH 5009
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated Remove: When wet or contaminated Change: Daily | First Aid (See procedures) Eye: Irrigate immediately Skin: Soap wash promptly Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH/OSHA Up to 50 mg/m3: (APF = 10) Any dust and mist respirator except single-use and quarter-mask respirators*/(APF = 10) Any supplied-air respirator* Up to 125 mg/m3: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode*/(APF = 25) Any powered, air-purifying respirator with a dust and mist filter* Up to 250 mg/m3: (APF = 50) Any air-purifying, full-facepiece respirator with a high-efficiency particulate filter/(APF = 50) Any powered, air-purifying respirator with a tight-fitting facepiece and a high-efficiency particulate filter*/(APF = 50) Any self-contained breathing apparatus with a full facepiece/(APF = 50) Any supplied-air respirator with a full facepiece Up to 1500 mg/m3: (APF = 2000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode 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 with a high-efficiency particulate filter/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin, mucous membrane; sensitization dermatitis
Target Organs Eyes, skin, respiratory system
See also: INTRODUCTION