CSLB C-33 Painting & DecoratingSafetyHard

A painting crew is working on a project that requires the use of MEK (Methyl Ethyl Ketone) as a solvent. According to OSHA, what is the Permissible Exposure Limit (PEL) for MEK over an 8-hour Time-Weighted Average (TWA)?

  1. A200 ppm
  2. B100 ppm
  3. C300 ppm
  4. D50 ppm
Show answer & explanation

Correct answer: A. 200 ppm

OSHA's Permissible Exposure Limit (PEL) for Methyl Ethyl Ketone (MEK) is 200 parts per million (ppm) averaged over an 8-hour workday (Time-Weighted Average, TWA). Exceeding this limit can lead to adverse health effects.

Why the other options are wrong

  • B. 100 ppm is incorrect for MEK; it's a common PEL for solvents like toluene.
  • C. 300 ppm is too high for MEK's PEL; it's sometimes a short-term exposure limit (STEL) for other substances.
  • D. 50 ppm is too low for MEK's PEL; it's closer to the PEL for some other solvents like xylene.

MEK PEL (OSHA)

The maximum concentration of Methyl Ethyl Ketone (MEK) that workers can be exposed to over an 8-hour workday without adverse health effects, as mandated by OSHA.

  • PEL stands for Permissible Exposure Limit.
  • MEK is a common industrial solvent.
  • Exposure above PEL can cause headaches, dizziness, and irritation.

Memory trick: MEK's PEL is 200, a standard for the workday crew.

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