# NIOSH Pocket Guide to Chemical Hazards
Benzene | CAS 71-43-2
C6H6 | RTECS CY1400000
Synonyms & Trade Names Benzol, Phenyl hydride | DOT ID & Guide 1114 130
Exposure Limits | NIOSH REL: Ca TWA 0.1 ppm ST 1 ppm See Appendix A
OSHA PEL: [1910.1028] TWA 1 ppm ST 5 ppm See Appendix F
IDLH Ca [500 ppm] | Conversion 1 ppm = 3.19 mg/m3
Physical Description Colorless to light-yellow liquid with an aromatic odor. [Note: A solid below 42°F.]
MW: 78.1 | BP: 176°F | FRZ: 42°F | Sol: 0.07%
VP: 75 mmHg | IP: 9.24 eV |  | Sp.Gr: 0.88
Fl.P: 12°F | UEL: 7.8% | LEL: 1.2% |
Class IB Flammable Liquid: Fl.P. below 73°F and BP at or above 100°F.
Incompatibilities & Reactivities Strong oxidizers, many fluorides & perchlorates, nitric acid
Measurement Methods NIOSH 1500, 1501, 3700, 3800; OSHA 12
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated Remove: When wet (flammable) Change: No recommendation Provide: Eyewash, Quick drench | First Aid (See procedures) Eye: Irrigate immediately Skin: Soap wash immediately Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration: (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 organic vapor canister/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin absorption, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin, nose, respiratory system; dizziness; headache, nausea, staggered gait; anorexia, lassitude (weakness, exhaustion); dermatitis; bone marrow depression; [potential occupational carcinogen]
Target Organs Eyes, skin, respiratory system, blood, central nervous system, bone marrow Cancer Site [leukemia]
See also: INTRODUCTION