# NIOSH Pocket Guide to Chemical Hazards
Formaldehyde | CAS 50-00-0
HCHO | RTECS LP8925000
Synonyms & Trade Names Methanal, Methyl aldehyde, Methylene oxide | DOT ID & Guide
Exposure Limits | NIOSH REL: Ca TWA 0.016 ppm C 0.1 ppm [15-minute] See Appendix A
OSHA PEL: [1910.1048] TWA 0.75 ppm ST 2 ppm
IDLH Ca [20 ppm] | Conversion 1 ppm = 1.23 mg/m3
Physical Description Nearly colorless gas with a pungent, suffocating odor. [Note: Often used in an aqueous solution (see specific listing for Formalin).]
MW: 30.0 | BP: -6°F | FRZ: -134°F | Sol: Miscible
VP: >1 atm | IP: 10.88 eV | RGasD: 1.04 |
Fl.P: NA (Gas) | UEL: 73% | LEL: 7.0% |
Flammable Gas
Incompatibilities & Reactivities Strong oxidizers, alkalis & acids; phenols; urea [Note: Pure formaldehyde has a tendency to polymerize. Reacts with HCl to form bis-Chloromethyl ether.]
Measurement Methods NIOSH 2016, 2541, 3500, 3800; OSHA ID205, 52
Personal Protection & Sanitation Skin: No recommendation Eyes: Prevent eye contact Wash skin: No recommendation Remove: No recommendation Change: No recommendation | First Aid (See procedures) Eye: Irrigate immediately Breathing: Respiratory support
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 canister providing protection against the compound of concern/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin and/or eye contact
Symptoms Irritation eyes, nose, throat, respiratory system; lacrimation (discharge of tears); cough; wheezing; [potential occupational carcinogen]
Target Organs Eyes, respiratory system Cancer Site [nasal cancer]
See also: INTRODUCTION