# NIOSH Pocket Guide to Chemical Hazards
Cyclopentadiene | CAS 542-92-7
C5H6 | RTECS GY1000000
Synonyms & Trade Names 1,3-Cyclopentadiene | DOT ID & Guide
Exposure Limits | NIOSH REL: TWA 75 ppm (200 mg/m3)
OSHA PEL: TWA 75 ppm (200 mg/m3)
IDLH 750 ppm | Conversion 1 ppm = 2.70 mg/m3
Physical Description Colorless liquid with an irritating, terpene-like odor.
MW: 66.1 | BP: 107°F | FRZ: -121°F | Sol: Insoluble
VP: 400 mmHg | IP: 8.56 eV |  | Sp.Gr: 0.80
Fl.P(oc): 77°F | UEL: ? | LEL: ? |
Class IC Flammable Liquid: Fl.P. at or above 73°F and below 100°F.
Incompatibilities & Reactivities Strong oxidizers, fuming nitric acid, sulfuric acid [Note: Polymerizes to dicyclopentadiene upon standing.]
Measurement Methods NIOSH 2523
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated Remove: When wet (flammable) Change: No recommendation | First Aid (See procedures) Eye: Irrigate immediately Skin: Soap wash promptly Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH/OSHA Up to 750 ppm: (APF = 10) Any chemical cartridge respirator with organic vapor cartridge(s)/(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/(APF = 25) Any powered, air-purifying respirator with organic vapor cartridge(s)/(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: (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, ingestion, skin and/or eye contact
Symptoms Irritation eyes, nose
Target Organs Eyes, respiratory system
See also: INTRODUCTION