Maleic anhydride

Synonyms & Trade Names

cis-Butenedioic anhydride, 2,5-Furanedione, Maleic acid anhydride, Toxilic anhydride

CAS No.

108-31-6

RTECS No.

ON3675000

DOT ID & Guide

2215 156

Formula

C₄H₂O₃

Conversion

1 ppm = 4.01 mg/m³

IDLH

10 mg/m³
See: 108316

Exposure Limits

NIOSH REL

TWA 1 mg/m³ (0.25 ppm)

OSHA PEL

TWA 1 mg/m³ (0.25 ppm)

Measurement Methods

NIOSH 3512;
OSHA 25 , 86
See: NMAM or OSHA Methods

Physical Description

Colorless needles, white lumps, or pellets with an irritating, choking odor.

Molecular Weight

98.1

Boiling Point

396°F

Melting Point

127°F

Solubility

Reacts

Vapor Pressure

0.2 mmHg

Ionization Potential

9.90 eV

Specific Gravity

1.48

Flash Point

218°F

Upper Explosive Limit

7.1%

Lower Explosive Limit

1.4%

Combustible Solid, but may be difficult to ignite.

Incompatibilities & Reactivities

Strong oxidizers, water, alkalis, metals, caustics & amines above 150°F [Note: Reacts slowly with water (hydrolyzes) to form maleic acid.]

Exposure Routes

inhalation, ingestion, skin and/or eye contact

Symptoms

irritation nose, upper respiratory system; conjunctivitis; photophobia (abnormal visual intolerance to light), double vision; bronchial asthma; 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

First Aid

(See procedures)
Eye:Irrigate immediately
Skin:Soap wash immediately
Breathing:Respiratory support
Swallow:Medical attention immediately

Respirator Recommendations

NIOSH/OSHA

Up to 10 mg/m³:
(APF = 25) Any supplied-air respirator operated in a continuous-flow mode^£
(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 having an N100, R100, or P100 filter.
Click here for information on selection of N, R, or P filters.
Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

Maleic anhydride

NIOSH REL

OSHA PEL

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