Maleic anhydride

CAS number: 108–31–6

NIOSH REL: 1 mg/m³ (0.25 ppm) TWA

Current OSHA PEL: 1 mg/m³ (0.25 ppm) TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 1 mg/m³ (0.25 ppm) TWA

Description of substance: Colorless needles, white lumps, or pellets with an irritating, choking odor.

LEL :. . 1.4% (10% LEL, 1,400 ppm)

Original (SCP) IDLH*: Unknown [*Note: "Effective" IDLH = 2,000 mg/m³ -- see discussion below.]

Basis for original (SCP) IDLH: No data on acute inhalation toxicity data are available on which to base an IDLH for maleic anhydride. MCA [1974] reported that it possesses little acute systemic toxic properties. For this draft technical standard, therefore, the respirators have been selected on the basis of the assigned protection factor afforded by each device up to 2,000 ´ the OSHA PEL of 1 mg/m³ (i.e., 2,000 mg/m³); only the "most protective" respirators are permitted for use in concentrations exceeding 2,000 mg/m³.

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA:

Lethal dose data:

Species	Reference	Route	LD50 (mg/kg)	LDLo (mg/kg)	Adjusted LD	Derived value
Mouse Rat Rabbit G. pig Rat	Berzin 1969 Berzin 1969 Izmerov et al. 1982 Izmerov et al. 1982 NCI 1974	oral oral oral oral oral	465 850 875 390 400	----- ----- ----- ----- -----	3,255 mg/m3 5,950 mg/m3 6,125 mg/m3 2,730 mg/m3 2,800 mg/m3	326 mg/m3 595 mg/m3 613 mg/m3 273 mg/m3 280 mg/m3

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].

Revised IDLH: 10 mg/m3 Basis for revised IDLH: The revised IDLH for maleic anhydride is 10 mg/m3 based on acute inhalation toxicity data in volunteers [IHFA 1969].

REFERENCES:

1. Berzin VI [1969]. Combined action of dinil and maleic anhydride on the organism. Gig Tr Prof Zabol 13(4):42-44 (in Russian).

2. Gervais P [1967]. L'asthme dans l'industries des matieres plastiques. Connaissance des Plastiques 7:21 (in French). [Abstract in Chem Abstr [1967]; 66(4):9043]. [From ACGIH [1991]. Maleic anhydride. In: Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 874-875.]

3. IHFA [1969]. Central data repository project. Pittsburgh, PA: Industrial Hygiene Foundation of America, Inc. [From ACGIH [1991]. Maleic anhydride. In: Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 874-875.]

4. Izmerov NF, Sanotsky IV, Sidorov KK [1982]. Toxicometric parameters of industrial toxic chemicals under single exposure. Moscow, Russia: Centre of International Projects, GKNT, p. 79.

5. MCA [1974]. Chemical safety data sheet sd-88: properties and essential information for safe handling and use of maleic anhydride. Washington, DC: Manufacturing Chemists Association, p. 1-13.

6. NCI [1974]. Memorandum. Interagency Collaborative Group on Environmental Carcinogens. National Cancer Institute, June 17, 1974.