Synonyms: o-, m-, and p-Isomers; Xylol; Dimethylbenzene; Methyl toluene

OSHA IMIS Code Number: 2590

Chemical Abstracts Service (CAS) Registry Number: 1330-20-7

Other Chemical Abstracts Service (CAS) Registry Numbers: 108-38-3 (m-Xylene); 95-47-6 (o-Xylene); 106-42-3 (p-Xylene)

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: ZE2275000 (m-Xylene); ZE2450000 (o-Xylene); ZE2625000 (p-Xylene)

Department of Transportation Regulation Number (49 CFR 172.101) and 2012 Emergency Response Guidebook [4 MB PDF, 392 pages]: 1307 130

NIOSH Pocket Guide to Chemical Hazards - m-Xylene, o-Xylene, and p-Xylene: Physical description, chemical properties, potentially hazardous incompatibilities, and more

EPA Hazard Summary - Xylenes: Uses, sources and potential exposure, acute and chronic health hazard information, and more

National Toxicology Program (NTP) carcinogenic classification: Not listed

International Agency for Research on Cancer (IARC) carcinogenic classification: Group 3 [74 KB PDF, 20 pages] (not classifiable as to its carcinogenicity in humans)

U.S. Environmental Protection Agency (EPA) carcinogenic classification: Data is inadequate for an assessment of human carcinogenic potential

EPA Inhalation Reference Concentration (RfC): 0.1 mg/m³

Agency for Toxic Substances and Disease Registry (ATSDR) Inhalation Minimal Risk Level (MRL): 2 ppm (acute); 0.6 ppm (intermediate); 0.05 ppm (chronic)

NIOSH Immediately Dangerous To Life or Health Concentration (IDLH): 900 ppm

Notes on Other Potential Health Effects and Hazards

1. The most commonly cited symptoms associated with xylene exposures are headache, fatigue, irritability, and gastrointestinal disturbances (ACGIH 2001).
2. May be involved in ototoxicity associated with exposure to solvents containing xylene (Sulkowski et al. 2002).
3. Urinary metabolites (presumed to be formed by CYP2E1), which are isomers of methylhippuric acid, are used for the biomonitoring of xylene exposure (Gonzales-Reche et al. 2003).
4. The EPA reference concentration is based on a subchronic study Impaired motor coordination (decreased rotarod  performance) study in male rats (Korsak et al., 1994).
5. ATSDR bases its minimal risk level on potential of xylenes to cause developmental liver, neurological and renal effects.

Date Last Revised: 11/16/2012

Literature Basis:

• ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Xylene (all isomers). 2001.
• ATSDR Toxicological Profile for Xylene, 2007
• EPA IRIS Xylenes 2003
• Gonzalez-Reche, L.M., Schettgen, T. and Angerer, J.: New approaches to the metabolism of xylenes: verification of the formation of phenylmercapturic acid metabolites of xylenes. Arch. Toxicol. 77(2): 80-85, 2003.
• Korsak, Z; Wisniewska-Knypl, J; Swiercz, R. (1994) Toxic effects of subchronic combined exposure to n-butyl alcohol and m-xylene in rats. Int J Occup Med Environ Health 7:155-166.
• NIOSH: Occupational Health Guideline for Xylene. 1978.
• NIOSH/IPCS: International Chemical Safety Cards - m-Xylene. 2002.
• NIOSH/IPCS: International Chemical Safety Cards - o-Xylene. 2002.
• NIOSH/IPCS: International Chemical Safety Cards - p-Xylene. 2002.
• Hood RD, Ottley MS Developmental effects associated with exposure to xylene: a review.
• Drug Chem Toxicol. 1985;8(4):281-97.
• Sulkowski, W.J. et al.: Effects of occupational exposure to a mixture of solvents on the inner ear - a field study. Int. J. Occup. Med. Environ. Health 15(3): 247-256, 2002.

Laboratory Sampling/Analytical Method:

• sampling media: Charcoal Tube (100/50 mg sections, 20/40 mesh)
  analytical solvent: Carbon Disulfide
  alternative solvent: (99:1) Carbon Disulfide:Dimethylformamide
  maximum volume: 12 Liters
  maximum flow rate: 0.05 L/min (TWA)
  minimum volume: 0.25 Liters
  maximum flow rate: 0.05 L/min (STEL)
  current analytical method: Gas Chromatography; GC/FID
  method reference: OSHA Analytical Method (OSHA 1002)
  method classification: Fully Validated



• sampling media: Diffusive Sampler (SKC 575-002 Passive Sampler)
  analytical solvent: Carbon Disulfide
  sampling time: 5 to 240 Minutes (TWA)
  current analytical method: Gas Chromatography; GC/FID
  method reference: OSHA Analytical Method (OSHA 1002)
  method classification: Fully Validated

On-Site Sampling Techniques/Methods:

• device: Detector Tube
  manufacturer: Gastec
  model/type: 123
  sampling information: 0.5 to 2 strokes
  upper measurement limit: 625 ppm
  detection limit: 1 ppm
  overall uncertainty: 16% for 10 to 50 ppm, 8% for 50 to 250 ppm
  method reference: on-site air secondary (SEI Certified)

• device: Detector Tube
  manufacturer: Matheson-Kitagawa
  model/type: 8014-143SA
  sampling information: 2 strokes
  upper measurement limit: 1000 ppm
  detection limit: approximately 2 ppm
  overall uncertainty: unknown
  method reference: on-site air secondary (SEI Certified)

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