You have been given good advice on what exposure limits to follow for protecting the worker.  Keep in mind that the Pocket Guide distinguishes between the exposure limits.  NIOSH publishes “Recommended Exposure Limits” (RELs) and OSHA publishes and enforces its “Permissible Exposure Limits” (PELs).  These limits are discussed in the Introduction of the NIOSH Pocket Guide under the heading Exposure Limits.  http://www .cdc.gov/niosh/npg/pgintrod.html#exposure  In Illinois private sector employees fall under federal OSHA.  State employees fall under the Illinois state plan.

Hello, all:

When the NIOSH pocket guide has different permissible limits (NIOSH versus OSHA), which is the better one to follow?

For example, benzene's limit for NIOSH is 0.1 ppm (10 hr workday), while OSHA's limit is 1 ppm (8 hour workday.)

Why the difference? From a legal perspective, which is a better choice?

Thanks in advance for any advice you might give; obviously, any advice people might give is non-binding, you're not responsible, legal mumbo-jumbo, blah, blah.

Cheers, Jim Tung

Lead Hazardous Waste Coordinator
Obiter Research LLC
Champaign, IL