Skip directly to local search Skip directly to A to Z list Skip directly to navigation Skip directly to site content Skip directly to page options
CDC Home
May 1994
 

Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs)


Phthalic anhydride

CAS number: 85–44–9

NIOSH REL: 6 mg/m3 (1 ppm) TWA

Current OSHA PEL: 12 mg/m3 (2 ppm) TWA

1989 OSHA PEL: 6 mg/m3 (1 ppm) TWA

1993-1994 ACGIH TLV: 6.1 mg/m3 (1 ppm) TWA

Description of substance: White solid (flake) or a clear, colorless, mobile liquid (molten) with a characteristic, acrid odor.

LEL: . . 1.7% (10% LEL, 10,500 mg/m3)

Original (SCP) IDLH: 10,000 mg/m3

Basis for original (SCP) IDLH: Because no data on acute inhalation toxicity are available on which to base an IDLH for phthalic anhydride, the chosen IDLH is based on repeated exposure data. AIHA [1967] reported that exposure of rats and rabbits to 10,000 mg/m3 for 4 hours/day for several days produced a 25% fatality rate [Malten and Zielhuis 1964].

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA:

Lethal dose data:

 

SpeciesReferenceRouteLD50

(mg/kg)

LDLo

(mg/kg)

Adjusted LDDerived value
RatBiofax 1970oral4,020-----28,140 mg/m3 2,814 mg/m3
MouseIzmerov et al. 1982 oral1,520-----10,500 mg/m31,050 mg/m3
CatMarhold 1986oral800-----5,600 mg/m3 560 mg/m3
RatPatty 1963oral800-1,600-----5,600 -11,200 mg/m3560 - 1,120 mg/m3
MouseZhilova & Kasparov 1969 oral2,210-----15,470 mg/m31,547 mg/m3

Other animal data: It has been reported that exposure of rats and rabbits to 10,000 mg/m3 for 4 hours/day for several days produced a 25% fatality rate [Malten and Zielhuis 1964].

Human data: It has been reported that an exposure of 30 mg/m3 is associated with conjunctivitis, while 25 mg/m3 is associated with signs of mucous membrane irritation [Baader 1955]. It has been stated that phthalic anhydride has similar toxic effects (i.e., irritation of the skin, eyes, and upper respiratory system) as maleic anhydride, but has reduced potency [ACGIH 1991].

 

Revised IDLH: 60 mg/m3

Basis for revised IDLH: Based on acute toxicity data in animals [Biofax 1970; Izmerov et al. 1982; Malten and Zielhuis 1964; Marhold 1986; Patty 1963; Zhilova and Kasparov 1969], a value between 600 and 3,000 mg/m3 would have been appropriate. However, the revised IDLH for phthalic anhydride is 60 mg/m3 (i.e., 10 times the NIOSH REL) based on acute inhalation data in humans [Baader 1955] and an analogy to maleic anhydride [ACGIH 1991] which has a revised IDLH that is 10 times its NIOSH REL. This may be a conservative value due to the lack of relevant acute toxicity data for workers exposed to concentrations above 30 mg/m3.

REFERENCES:

1. ACGIH [1991]. Phthalic anhydride. In: Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 1263-1264.

2. AIHA [1967]. Phthalic anhydride. In: Hygienic guide series. Am Ind Hyg Assoc J 28:395-398.

3. Baader EW [1955]. Diseases due to phthalic acid and its compounds. Arch Gewerbepath Gewerbehyg 13:419-453 (in German).

4. Biofax [1970]. Phthalic anhydride. Northbrook, IL: Biofax Industrial Bio-Test Laboratories, Inc.

5. Izmerov NF, Sanotsky IV, Sidorov KK [1982]. Toxicometric parameters of industrial toxic chemicals under single exposure. Moscow, Russia: Centre of International Projects, GKNT, p. 322.

6. Malten KE, Zielhuis RL [1964]. Alkyd resins. In: Industrial toxicology and dermatology in the production and processing of plastics. Amsterdam, The Netherlands: Elsevier Publishing Company, pp. 59-70.

7. Marhold J [1986]. Prehled Prumyslove Toxikologie, Organicke Latky. Prague, Czechoslovakia: Avicenum, p. 322 (in Czechoslovakian).

8. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., pp. 1822-1823.

9. Zhilova NA, Kasparov AA [1969]. Phthalic anhydride and n-nitrosodiphenylamine (Vulcalent A). Chem Abstr 71:280.

 
Contact Us:
USA.gov: The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Road Atlanta, GA 30329-4027, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC–INFO