NIOSH Pocket Guide to Chemical Hazards

Ketene CAS 463-51-4
CH2=CO RTECS OA7700000
Synonyms & Trade Names
Carbomethene, Ethenone, Keto-ethylene
DOT ID & Guide
NIOSH REL: TWA 0.5 ppm (0.9 mg/m3) ST 1.5 ppm (3 mg/m3)
OSHA PEL†: TWA 0.5 ppm (0.9 mg/m3)
IDLH 5 ppm Conversion 1 ppm = 1.72 mg/m3
Physical Description
Colorless gas with a penetrating odor.
MW: 42.0
BP: -69°F
FRZ: -238°F
Sol: Reacts
VP: >1 atm
IP: 9.61 eV
RGasD: 1.45

Fl.P: NA (Gas)
UEL: ?
LEL: ?

Flammable Gas
Incompatibilities & Reactivities
Water, alcohols, ammonia [Note: Readily polymerizes. Reacts with water to form acetic acid.]
Measurement Methods
NIOSH S92 (II-2)
Personal Protection & Sanitation
Skin: No recommendation
Eyes: No recommendation
Wash skin: No recommendation
Remove: No recommendation
Change: No recommendation

First Aid (See procedures)

Breathing: Respiratory support

Respirator Recommendations NIOSH/OSHA
Up to 5 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 organic vapor canister/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin and/or eye contact
Symptoms Irritation eyes, skin, nose, throat, respiratory system; pulmonary edema
Target Organs Eyes, skin, respiratory system