Definition of Reasonable Diligence as stated in 1910.1096(d)(1).

This is an OSHA interpretation letter responding to Senator McCain on how "reasonable diligence" under 29 CFR 1910.1096(d)(1) applies to employer knowledge of elevated radon-222 in workplaces. It states that the definition depends on case-specific facts and that an EPA report or media coverage of excessive radon in the area could trigger a duty to test or inquire.