NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

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 See: 542927
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 73F and below 100F.
Incompatibilities & Reactivities

Strong oxidizers, fuming nitric acid, sulfuric acid [Note: Polymerizes to dicyclopentadiene upon standing.]
Measurement Methods
NIOSH 2523
See: NMAM or OSHA Methods
Personal Protection & Sanitation
(See protection)
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
Important additional information about respirator selection
Exposure Routes
inhalation, ingestion, skin and/or eye contact
Symptoms
Irritation eyes, nose
Target Organs
Eyes, respiratory system
See also: INTRODUCTION   See ICSC CARD: 0857