1. Knowing the limits... of limit values

"Compliance with limit values does not imply the absence of risk. Indeed... scientific knowledge is constantly evolving... only penetration into the body through the respiratory tract is taken into account... For certain substances... there is no threshold below which exposure no longer presents any risk..." ( circulaire DGT 2010/03 du 13 avril 2010 ).

The concept of an OEL reflects the absence of risk only for substances whose effects only manifest themselves above a certain concentration threshold. For substances with toxic effects without a threshold, such as genotoxins, an OEL corresponds to a statistical break at a level at which the risk is considered negligible (but not non-existent).

Occupational exposure limits...