Maleic anhydride

Agent Name
Maleic anhydride
CAS Number
108-31-6
Formula
C4-H2-O3
Major Category
Plastics & Rubber
Maleic anhydride formula graphical representation
Synonyms
cis-Butenedioic anhydride; 2,5-Furanedione; Maleic acid anhydride; Toxilic anhydride; [NIOSH]
Category
Acid Anhydrides, Cyclic
Description
Colorless needles, white lumps, or pellets with an irritating, choking odor; [NIOSH] Deliquescent; [CHEMINFO]
Sources/Uses
Used in Diel-Alder syntheses; copolymerization reactions; and manufacturing of alkyd-type resins, dye intermediates, pharmaceuticals, and pesticides (Malathion). [Merck Index] Other uses are coatings, epoxies, and paper sizing resins; [ACGIH]
Comments
Causes respiratory distress and lung hemorrhage in rats inhaling 86 mg/m3 six hours/day, five days/week for four weeks; Causes severe corneal ulcerations after instillation into rabbit eyes; A dermal sensitizer based on animal testing and limited data in humans; [ACGIH] Solid form causes first degree burns on short exposure; [CHRIS] Maleic anhydride is a skin irritant. [Quick CPC] Maleic anhydride is a severe eye irritant; [HSDB] Causes occupational asthma: a 34 year old male developed asthma 1 month after starting work in a plant manufacturing polyurethane products. The patient showed a dual asthmatic response after specific inhalation challenge with maleic anhydride. [Reference #1] Maleic anhydride can cause contact urticaria. [Occupational allergic contact urticaria from maleic anhydride. Kanerva L, et al. Contact Dermatitis. 2000 Mar;42(3):170-2. No abstract available.] Danger of skin and airway sensitization; [MAK] See "ACID ANHYDRIDES."
Biomedical References

Exposure Assessment

Skin Designation (ACGIH)
No
TLV (ACGIH)
0.01 mg/m3, Inhalable fraction and vapor
PEL (OSHA)
1 mg/m3
MAK
0.081 mg/m3, Ceiling = 0.2 mg/m3
IDLH (NIOSH)
10 mg/m3
Excerpts from Documentation for IDLHs
Human data: In volunteers, 6 to 8 mg/m3 caused nasal irritation within 1 minute and ocular irritation after 15 to 20 minutes [Gervais 1967]. In another study, concentrations of 10 mg/m3 and higher were found to be extremely irritating [IHFA 1969].
Vapor Pressure
0.25 mm Hg
Odor Threshold Low
0.25 ppm
Odor Threshold High
0.32 ppm
Explanatory Notes
Odor threshold from AIHA; VP from HSDB;
Reference Link #2
NFPA
must be preheated
ERPG-1
0.2 ppm
ERPG-2
2 ppm
ERPG-3
20 ppm

Adverse Effects

Skin Sensitizer
Yes
Asthma
Yes
Toxic Pneumonitis
Yes
Dermatotoxin
Skin burns
ACGIH Carcinogen
Not Classifiable

Diseases, Processes, and Activities Linked to This Agent

Diseases

Occupational diseases associated with exposure to this agent: