Q.01

How do I use the OSHA chemical database?

You can look up a chemical in OSHA's Occupational Chemical Database at osha.gov/chemicaldata by name, CAS number or OSHA analyte code, or by browsing an A-Z list. Each chemical page brings together identifiers, physical properties, exposure limits from several bodies and OSHA's sampling methods. OSHA calls it its "one-stop shop" for occupational chemical information, compiled from several government agencies and organizations.

Approach: I read OSHA's official database pages: the home page, the Advanced Search form and one example chemical record.

1. Finding a chemical

  • Browse by name: use the Chemical Name A-Z Index.
  • Advanced Search: you can search by:
    • Chemical name, in full or just part of it.
    • CAS number, in full (for example 7782-50-5) or part of it (for example 7782-5).
    • Analyte Code (IMIS #), which is OSHA's own ID for each chemical.
    • Two checkboxes narrow the results: chemicals with carcinogenic classifications, and chemicals with an IDLH value in ppm.
  • Results show the chemical name, CAS number, analyte code and synonyms, 50 per page. The search page says the database holds 838 chemicals.

2. What a chemical page shows

Using vinyl toluene (chemicaldata/322) as the example, a page has these sections:

  1. Chemical Identification: CAS number (25013-15-4), formula and synonyms.
  2. Physical Properties: boiling point, flash point, specific gravity, and lower and upper explosive limits.
  3. Monitoring Methods Used by OSHA: sampling media, the analytical instrument and the OSHA method number. For vinyl toluene that is OSHA method 89, using a coated CSC tube and GC-FID.
  4. Bulk/Wipe Method and On-Site Screening Techniques.
  5. Exposure Limits: limits from different bodies side by side. For vinyl toluene:
SourceLimit
OSHA PEL-TWA100 ppm (480 mg/m³)
NIOSH REL-TWA100 ppm (480 mg/m³)
ACGIH TLV-TWA50 ppm [1992]
Cal/OSHA PEL-TWA50 ppm (240 mg/m³)
IDLH400 ppm
  1. Additional Resources and Literature References.

3. Tips

  • Check each limit's source. Limits on the same page can differ: here the OSHA PEL is 100 ppm, while the ACGIH TLV and Cal/OSHA PEL are 50 ppm. Note which body set the figure you are relying on.
  • PEL coverage: OSHA's Permissible Exposure Limits cover about 400 substances, and the database refers to OSHA standards for General Industry, Construction and Maritime. Use the standard citations it gives for the binding text.
  • Abbreviations: the field/label abbreviations guide explains the column labels.
  • Sampling: for planning monitoring, the Sampling and Analytical Methods section lists media, flow rates and method links.
  • Measured exposure data: OSHA publishes this separately as Chemical Exposure Health Data.

If you give me a substance name or CAS number, I can pull its exposure limits and compare them with EU or GB occupational exposure limits.

Q.02