NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

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] See: 59355758
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
See: NMAM or OSHA Methods
Personal Protection & Sanitation
(See protection)
Skin: Frostbite
Eyes: Frostbite
Wash skin: No recommendation
Remove: When wet (flammable)
Change: No recommendation
Provide: Frostbite wash
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
Important additional information about respirator selection
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