# NIOSH Pocket Guide to Chemical Hazards
Crotonaldehyde | CAS 4170-30-3
CH3CH=CHCHO | RTECS GP9499000
Synonyms & Trade Names 2-Butenal, beta-Methyl acrolein, Propylene aldehyde | DOT ID & Guide 1143 131P (inhibited)
Exposure Limits | NIOSH REL: TWA 2 ppm (6 mg/m3) See Appendix C (Aldehydes)
OSHA PEL: TWA 2 ppm (6 mg/m3)
IDLH 50 ppm | Conversion 1 ppm = 2.87 mg/m3
Physical Description Water-white liquid with a suffocating odor. [Note: Turns pale-yellow on contact with air.]
MW: 70.1 | BP: 219°F | FRZ: -101°F | Sol: 18%
VP: 19 mmHg | IP: 9.73 eV |  | Sp.Gr: 0.87
Fl.P: 45°F | UEL: 15.5% | LEL: 2.1% |
Class IB Flammable Liquid: Fl.P. below 73°F and BP at or above 100°F.
Incompatibilities & Reactivities Caustics, ammonia, strong oxidizers, nitric acid, amines [Note: Polymerization may occur at elevated temperatures, such as in fire conditions.]
Measurement Methods NIOSH 3516; OSHA 81
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: Water flush immediately Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH/OSHA Up to 20 ppm: (APF = 10) Any chemical cartridge respirator with organic vapor cartridge(s)*/(APF = 10) Any supplied-air respirator* Up to 50 ppm: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode*/(APF = 25) Any powered, air-purifying respirator with organic vapor cartridge(s)*/(APF = 50) Any chemical cartridge respirator with a full facepiece and 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 = 50) Any self-contained breathing apparatus with a full facepiece/(APF = 50) Any supplied-air respirator 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, respiratory system; in animals: dyspnea (breathing difficulty), pulmonary edema, irritation skin
Target Organs Eyes, skin, respiratory system
See also: INTRODUCTION