# NIOSH Pocket Guide to Chemical Hazards
Diacetone alcohol | CAS 123-42-2
CH3COCH2C(CH3)2OH | RTECS SA9100000
Synonyms & Trade Names Diacetone, 4-Hydroxy-4-methyl-2-pentanone, 2-Methyl-2-pentanol-4-one | DOT ID & Guide 1148 129
Exposure Limits | NIOSH REL: TWA 50 ppm (240 mg/m3)
OSHA PEL: TWA 50 ppm (240 mg/m3)
IDLH 1800 ppm [10%LEL] | Conversion 1 ppm = 4.75 mg/m3
Physical Description Colorless liquid with a faint, minty odor.
MW: 116.2 | BP: 334°F | FRZ: -47°F | Sol: Miscible
VP: 1 mmHg | IP: ? |  | Sp.Gr: 0.94
Fl.P: 125°F | UEL: 6.9% | LEL: 1.8% |
Class II Combustible Liquid: Fl.P. at or above 100°F and below 140°F.
Incompatibilities & Reactivities Strong oxidizers, strong alkalis
Measurement Methods NIOSH 1402; OSHA 7
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated Remove: When wet or contaminated Change: No recommendation | First Aid (See procedures) Eye: Irrigate immediately Skin: Water flush promptly Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH/OSHA Up to 1250 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)£ Up to 1800 ppm: (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 powered, air-purifying respirator with a tight-fitting facepiece and organic vapor cartridge(s)£/(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, skin, nose, throat; corneal damage; in animals: narcosis, liver damage
Target Organs Eyes, skin, respiratory system, central nervous system, liver
See also: INTRODUCTION