# NIOSH Pocket Guide to Chemical Hazards
Methyl acetylene-propadiene mixture | CAS 59355-75-8
C3H4 | RTECS UK4920000
Synonyms & Trade Names MAPP gas, Methyl acetylene-allene mixture, Methyl acetylene-propadiene mixture (stabilized), Propadiene-methyl acetylene, Propyne-allene mixture, Propyne-propadiene mixture | DOT ID & Guide 1060 116P (stabilized)
Exposure Limits | NIOSH REL: TWA 1000 ppm (1800 mg/m3) ST 1250 ppm (2250 mg/m3)
OSHA PEL†: TWA 1000 ppm (1800 mg/m3)
IDLH 3400 ppm [10%LEL] | Conversion 1 ppm = 1.64 mg/m3
Physical Description Colorless gas with a strong, characteristic, foul odor. [Note: A fuel that is shipped as a liquefied compressed gas.]
MW: 40.1 | BP: -36 to -4°F | FRZ: -213°F | Sol: Insoluble
VP: >1 atm | IP: ? | RGasD: 1.48 |
Fl.P: NA (Gas) | UEL: 10.8% | LEL: 3.4% |
Flammable Gas
Incompatibilities & Reactivities Strong oxidizers, copper alloys [Note: Forms explosive compounds at high pressure in contact with alloys containing more than 67% copper.]
Measurement Methods NIOSH S85 (II-6); OSHA 7
Personal Protection & Sanitation Skin: Frostbite Eyes: Frostbite Wash skin: No recommendation Remove: When wet (flammable) Change: No recommendation Provide: Frostbite | First Aid (See procedures) Eye: Frostbite Skin: Frostbite Breathing: Respiratory support
Respirator Recommendations NIOSH/OSHA Up to 3400 ppm: (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 canister providing protection against the compound of concern/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin and/or eye contact (liquid)
Symptoms Irritation respiratory system; excitement, confusion, anesthesia; liquid: frostbite
Target Organs respiratory system, central nervous system
See also: INTRODUCTION