That concentration of oxygen by volume below which atmosphere supplying respiratory protection must be provided. It exists in atmospheres where the percentage of oxygen by volume is less than 19.5 percent oxygen.
An atmosphere having less than the normal amount (21%) of oxygen. When oxygen concentration in air falls dangerously low to 19.5% or less, many people become dizzy, experience a buzzing in the ears, have a rapid heartbeat, become confused, or lose consciousness.
Oxygen deficiency occurs in atmospheres containing less than 19.5 percent oxygen.
An atmosphere having less than the normal percentage of oxygen found in normal air. Normal air contains 21% oxygen at sea level.
Atmosphere conditions where less than 19.5% oxygen is present. An atmosphere with less than 16.5% oxygen is considered immediately dangerous to life or health.
Insufficient oxygen to support life or to support flame. When oxygen content of the air falls below 16 percent, flame production is reduced and Firefighters are in danger of asphyxiation from oxygen deficiency; below six percent, breathing ceases. In addition to oxygen deficiency, there is danger from smoke, heat, and gases unless firefighters are protected by SCBA; and these conditions may become serious before oxygen deficiency is acute.
Insufficiency of oxygen to support combustion. (See also Ventilation-Controlled Fire.)
Hazardous atmospheric condition due to a low oxygen concentration. OSHA (29 CFR 1910.146) defines oxygen concentrations which are less than 19.5% as hazardous due to oxygen deficiency.
An atmosphere having less that 21% oxygen.
Insufficient oxygen to support life or flame; atmospheric lower limits of 16 percent oxygen is needed for flame production and supporting human life. Defined by OSHA as ambient air containing less than 19.5% oxygen concentration.
