Atmosphere that has the potential to expose entrants to the risk of death, incapacitation, impaired ability to self-rescue (e.g. escape unaided from a permit required confined space), injury, or acute illness from one or more of the following causes:
- flammable gas, vapor, or mist in excess of 10 % LEL;
- airborne combustible dust at a concentration that meets or exceeds its LEL;
- atmospheric oxygen concentrations below 19.5 % and above 23.5 %;
- atmospheric concentration of any substance for which a dose or OEL is published in applicable government regulations, safety data sheets (SDS), standards, or other published or internal documents and could result in responder exposure in excess of its dose or PEL;
- any other IDLH atmospheric condition.
Source: API RP 98, Personal Protective Equipment Selection for Oil Spill Responders, First Edition, August 2013. Global Standards
An atmosphere that may expose employees to the risk of death, incapacitation, impairment of ability to self rescue, injury, or acute illness from oxygen deficiency or enrichment; flammability or explosion potential; or toxicity [as set forth in OSHA 29 CFR 1910.146(b)].
Source: API Standards 2217A, Guidelines for Safe Work in Inert Confined Spaces in the Petroleum and Petrochemical Industries, Fourth Edition, July 2009. Global Standards
Hazardous atmosphere means any atmosphere that is immediately dangerous to life or health.
Source: IMO Resolution MSC.98(73), Adoption of the International Code for Fire Safety Systems (FSS Code), 5 December 2000, International Maritime Organization. Regulatory Guidance.
Source: IMO resolution MSC.98(73), The International Code for Fire Safety Systems, 5 December 2000, International Maritime Organization. Regulatory Guidance