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Chemical Sampling Information (CSI)
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General Description

Synonyms: 1,2-Benzenedicarboxylic anhydride; 1,2 Benzene-dicarboxylic acid anhydride; 1,3, Dioxophthalan; 1,3 Isobenzoflurandione; PAN; Phthalic acid anhydride

OSHA IMIS Code Number: 2110

Chemical Abstracts Service (CAS) Registry Number: 85-44-9

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: TI3150000

Department of Transportation Regulation Number (49 CFR 172.101) and Guide: 2214 156

NIOSH Pocket Guide to Chemical Hazards, Phthalic Anhydride: chemical description, physical properties, potentially hazardous incompatibilities, and more

Exposure Limits

OSHA Permissible Exposure Limit (PEL):

General Industry: 29 CFR 1910.1000 Z-1 Table -- 2 ppm, 12 mg/m3 TWA

Construction Industry: 29 CFR 1926.55 Appendix A -- 2 ppm, 12 mg/m3 TWA

Maritime: 29 CFR 1915.1000 Table Z-Shipyards -- 2 ppm, 12 mg/m3 TWA

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): 1 ppm, 6.1 mg/m3 TWA; SEN; Appendix A4 - Not Classifiable as a Human Carcinogen

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): 1 ppm, 6 mg/m3 TWA

Health Factors

NIOSH Immediately Dangerous To Life or Health Concentration (IDLH): 60 mg/m3

Potential Symptoms: Irritation of eyes, skin, upper respiratory system, conjunctivitis, nasal ulcer bleeding; cough, sore throat, wheezing, bronchitis; bronchial asthma; dermatitis; in animals: liver, kidney damage

Health Effects: Irritation- Eye, Nose, Throat, Skin---Marked (HE14) Asthma (HE9); Contact skin irritant and sensitizer (HE3)

Affected Organs: Eyes, skin, respiratory system, liver, kidneys


  1. EPA’s oral reference dose (daily oral exposure likely to be without an appreciable risk of deleterious effects during a lifetime) for phthalic anhydride is 2.0 mg/kg/day. EPA’s provisional reference concentration in air is 0.12 mg/m3.
  2. Irritation of moist mucosa or wet skin may be due to the conversion of phthalic anhydride to phthalic acid by contact with water.
  3. The urinary excretion of phthalic acid has been measured to study employee exposure to airborne phthalic anhydride.
  4. Phthalic anhydride in plastic film and labels used to package meats was reported to be the major cause of “meat wrapper’s asthma.”

Literature Basis:

  • NIOSH Pocket Guide to Chemical Hazards: Phthalic anhydride.
  • International Chemical Safety Cards (WHO/IPCS/ILO): Phthalic anhydride.
  • EPA Air Toxics Website: Phthalic anhydride. US Environmental Protection Agency Technology Transfer Network.
  • Liss, G.M., Albro, P.W., Hartle, R.W. and Stringer, W.T.: Urine phthalate determinations as an index of occupational exposure to phthalic anhydride and di(2-ethylhexyl)phthalate. Scand. J. Work Environ. Health 11(5): 381-387, 1985.
  • Pauli, G., et al.: Meat wrapper’s asthma: identification of the causal agent. Clin. Allergy 10(3): 263-269, 1980.
  • Pfaffli, P.: Phthalic acid excretion as an indicator of exposure to phthalic anhydride in the work atmosphere. Int. Arch. Occup. Environ. Health 58(3): 209-216, 1986.
  • Pohanish, R.P. (editor): Phthalic anhydride. In, Sittig’s Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1879-1881.

Date Last Revised: 09/27/2006

Monitoring Methods used by OSHA

Primary Laboratory Sampling/Analytical Method (SLC1):

  • sampling media: Two Coated Glass Fiber Filters (37 mm) Coating is 10 mg Veratryamine.
    analytical solvent: (90:10) Acetonitrile: Dimethylsulfoxide
    maximum volume: 75 Liters
    maximum flow rate: 1.0 L/min
    current analytical method: High Performance Liquid Chromatography; HPLC/UV
    method reference: OSHA Analytical Method (OSHA 90)
    method classification: Fully Validated
    note: Store filters under refrigeration and use within 1 month. Small interfering peaks start appearing after that time.

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