Permissible Exposure Limits

Permissible Exposure Limits

Most commonly used solvent vapors have “Permissible Exposure Limits” (PELs) or allowable amounts in the air. Most of these limits are based on average 8-hour exposures – a few are peak or ceiling limits. The lower the limit, the more toxic the solvent is. Examples of PELs for common solvents:

  • acetone – 750 ppm                                      xylene – 100 ppm
  • isopropyl alcohol – 400 ppm                     toluene – 100 ppm
  • MEK – 200 ppm                                           ethyl benzene – 100 ppm
  • turpentine – 100 ppm                                  trichloroethylene – 50 ppm

ppm = parts per million 10,000 ppm = 1% in air

Some Especially Dangerous Solvents

  • Benzene –blood damage and leukemia
  • N-hexane – peripheral neuropathy (tingling & numbness in hands and feet)
  • Methanol – blindness
  • Carbon tetrachloride – severe liver & kidney damage
  • Certain Freons – irregular heartbeat
  • Certain glycol ethers – damage to fetus, lowered sperm count, blood damage

Many of these chemicals are no longer used because of their high health hazards. However, they may occasionally show up in products in small amounts, in products from other countries, or as an unintended contaminant.