Acetic anhydride

Synonyms & Trade Names

Acetic acid anhydride, Acetic oxide, Acetyl oxide, Ethanoic anhydride

CAS No.

108-24-7

RTECS No.

AK1925000

DOT ID & Guide

1715 137

Formula

(CH₃CO)₂O

Conversion

1 ppm = 4.18 mg/m³

IDLH

200 ppm
See: 108247

Exposure Limits

NIOSH REL

C 5 ppm (20 mg/m³)

OSHA PEL

TWA 5 ppm (20 mg/m³) See Appendix G

Measurement Methods

NIOSH 3506;
OSHA 82 , 102
See: NMAM or OSHA Methods

Physical Description

Colorless liquid with a strong, pungent, vinegar-like odor.

Molecular Weight

102.1

Boiling Point

282°F

Freezing Point

-99°F

Solubility

12%

Vapor Pressure

4 mmHg

Ionization Potential

10.00 eV

Specific Gravity

1.08

Flash Point

120°F

Upper Explosive Limit

10.3%

Lower Explosive Limit

2.7%

Class II Combustible Liquid: Fl.P. at or above 100°F and below 140°F.

Incompatibilities & Reactivities

Water, alcohols, strong oxidizers (especially chromic acid), amines, strong caustics [Note: Corrosive to iron, steel & other metals. Reacts with water to form acetic acid.]

Exposure Routes

inhalation, ingestion, skin and/or eye contact

Symptoms

conjunctivitis, lacrimation (discharge of tears), corneal edema, opacity, photophobia (abnormal visual intolerance to light); nasal, pharyngeal irritation; cough, dyspnea (breathing difficulty), bronchitis; skin burns, vesiculation, sensitization dermatitis

Target Organs

Eyes, skin, respiratory system

Personal Protection/Sanitation

(See protection codes)
Skin:Prevent skin contact
Eyes:Prevent eye contact
Wash skin:When contaminated
Remove:When wet or contaminated
Change:No recommendation
Provide:Eyewash, Quick drench

First Aid

(See procedures)
Eye:Irrigate immediately
Skin:Water flush immediately
Breathing:Respiratory support
Swallow:Medical attention immediately

Respirator Recommendations

NIOSH/OSHA

Up to 125 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 200 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

Important additional information about respirator selection

Acetic anhydride

NIOSH REL

OSHA PEL

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