Observed condition or measured level of exposure to a harmful substance, condition, or hazard that would identify the need for the implementation of a management action, at times determined by regulatory mandate, appropriate to address such condition.
Source: API RP 98, Personal Protective Equipment Selection for Oil Spill Responders, First Edition, August 2013. Global Standards
The levels at which the possibility of hydrogen sulfide atmospheric concentrations greater than 10 ppm or sulfur dioxide atmospheric concentrations greater than 2 ppm may be encountered.
Source: API RP 49, Recommended Practice for Drilling and Well Servicing Operations Involving Hydrogen Sulfide, Third Edition, May 2001. Global Standards