Agent Name

Trimellitic anhydride

CAS Number

552-30-7

Formula

C9-H4-O5

Major Category

Plastics & Rubber

Synonyms

1,2,4-Benzenetricarboxylic anhydride; 4-Carboxyphthalic anhydride; TMA; TMAN; Trimellic acid anhydride; [Note: TMA is also a synonym for Trimethylamine.]; [NIOSH]

Category

Acid Anhydrides, Cyclic

Description

Colorless solid; [NIOSH]

Sources/Uses

Used primarily as a curing agent for alkyl and epoxy resins; [Rom p. 1213] Used in the synthesis of, or as a curing agent for, epoxy resins, plasticizers, paints, wall and floor coverings, and insulation for cable and wire; [ACGIH]

Comments

There are three syndromes caused by trimellitic anhydride (TMA) based on its ability to irritate and sensitize lung tissue. Sensitized workers can develop upon re-exposure 1) asthma-rhinitis; 2) late respiratory systemic syndrome (LRSS); or very rarely 3) pulmonary disease anemia syndrome (PDA). [Grammer LC et al. Review of trimellitic anhydride (TMA) induced respiratory response. Allergy Asthma Proc 1997 Jul-Aug;18(4):235-7] Workers exposed to less than 0.002 mg/m3 are at low risk for developing disease. [Grammer LC et al. A Clinical and Immunologic Study to Assess Risk of TMA-Induced Lung Disease as Related to Exposure. JOEM 1999 Dec;41(12):1048-51] TMAN is a potent sensitizer after inhalation of either dust or fume. It causes IgE and IgG mediated disease (asthma/rhinitis, late respiratory systemic syndrome, pulmonary disease anemia, and late arthralgia myalgia). Symptoms include sneezing, rhinitis, dry throat, watery eyes, conjunctivitis, and dyspnea. Dermal contact may cause or exacerbate respiratory sensitization. When workers are not exposed to >2 ug/m3, there are no cases of disease or IgG against TM-HAS (Human Serum Albumin), but there are still cases of non-diseased workers with IgE against TM-HAS (9% incidence). TMAN cause both immediate and delayed dermal sensitization in animal studies. [ACGIH] Danger of airway sensitization; [MAK] "TMA skin testing provides an alternative and potentially more practical method for monitoring TMA-exposed workers for developing IgE sensitization." [PMID 21915071] See "ACID ANHYDRIDES."

Reference Link

Review of trimellitic anhydride (TMA) induced respiratory response

Exposure Assessment
Skin Designation (ACGIH)

Yes

TLV (ACGIH)

0.0005 mg/m3, inhalable fraction and vapor

STEL (ACGIH)

0.002 mg/m3, inhalable fraction and vapor

MAK

0.04 mg/m3

Vapor Pressure

4.0E-6 mm Hg

Reference Link

A clinical and immunologic study to assess risk of TMA-induced lung disease as related to exposure

Adverse Effects
Asthma

Yes

Toxic Pneumonitis

Yes

Fibrogenic

Yes

Anemia

Anemia, Hemolytic

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Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure: