# NIOSH Pocket Guide to Chemical Hazards
beta-Chloroprene | CAS 126-99-8
CH2=CClCH=CH2 | RTECS EI9625000
Synonyms & Trade Names 2-Chloro-1,3-butadiene; Chlorobutadiene; Chloroprene | DOT ID & Guide 1991 131P (inhibited)
Exposure Limits | NIOSH REL: Ca C 1 ppm (3.6 mg/m3) [15-minute] See Appendix A
OSHA PEL†: TWA 25 ppm (90 mg/m3) [skin]
IDLH Ca [300 ppm] | Conversion 1 ppm = 3.62 mg/m3
Physical Description Colorless liquid with a pungent, ether-like odor.
MW: 88.5 | BP: 139°F | FRZ: -153°F | Sol: Slight
VP: 188 mmHg | IP: 8.79 eV |  | Sp.Gr: 0.96
Fl.P: -4°F | UEL: 11.3% | LEL: 1.9% |
Class IB Flammable Liquid: Fl.P. below 73°F and BP at or above 100°F.
Incompatibilities & Reactivities Peroxides & other oxidizers [Note: Polymerizes at room temperature unless inhibited with antioxidants.]
Measurement Methods NIOSH 1002; OSHA 112
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, respiratory system; anxiety, irritability; dermatitis; alopecia; reproductive effects; [potential occupational carcinogen]
Target Organs Eyes, skin, respiratory system, reproductive system Cancer Site [lung & skin cancer]
See also: INTRODUCTION