Personal protective equipment for IDLH conditions: pressure-demand supplied-air respirator equipped with a full facepiece in combination with an auxiliary pressure-demand self-contained breathing apparatus The term<unk>  (IDLH) is defined by the US National Institute for Occupational Safety and<unk>  (NIOSH) as exposure to airborne contaminants that is "likely to cause death or immediate or delayed permanent adverse<unk>  effects or prevent escape from such an environment." Examples include smoke or other poisonous gases at sufficiently high concentrations. It is calculated using the LD50 or LC50. The Occupational Safety and<unk>  Administration (OSHA) regulation (1910.134(b)) defines the term as "an atmosphere that poses an immediate threat to<unk> , would cause irreversible adverse<unk>  effects, or would impair an individual's ability to escape from a<unk>  atmosphere." IDLH values are often used to guide the selection of breathing apparatus that are made available to workers or firefighters in specific situations. The NIOSH definition does not include oxygen deficiency (below 19.5 percent) although atmosphere-supplying breathing apparatus is also required. Examples include high altitudes and unventilated, confined spaces. The OSHA definition is arguably broad enough to include oxygen-deficient circumstances in the absence of "airborne contaminants", as well as many other chemical, thermal, or pneumatic hazards to<unk>  or<unk>  (e.g., pure helium, super-cooled or super-heated air, hyperbaric or hypo-baric or submerged chambers, etc.). It also uses the broader term "impair", rather than "prevent", with respect to the ability to escape. For example, blinding but non-toxic smoke could be considered IDLH under the OSHA definition if it would impair the ability to escape a<unk> " but not<unk> -threatening atmosphere (such as tear gas). The OSHA definition is part of a legal standard, which is the minimum legal requirement. Users or employers are encouraged to apply proper judgment to avoid taking unnecessary risks, even if the only immediate hazard is "reversible", such as temporary pain, disorientation, nausea, or non-toxic contamination.
Immediately dangerous to life or health
Safety of emergency medical services flights
Drug Safety
In Case of Emergency
Modesty in medical settings
Serious Hazards of Transfusion
Automotive safety
The Dose Makes the Poison