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OSHA requires employers who send workers into areas where the oxygen concentration is known or expected to be less than 19.5% to follow the provision of the Respiratory Protection Standard [29 CFR 1910.134]. Generally, work in an oxygen depleted environment requires an SCBA or airline respirator.
Many organisms require hypoxic conditions. Oxygen is poisonous to anaerobic bacteria for example. [3] Oxygen depletion is typically expressed as a percentage of the oxygen that would dissolve in the water at the prevailing temperature and salinity. A system with low concentration—in the range between 1 and 30% saturation—is called hypoxic ...
It is calculated using the LD50 or LC50. [1] The Occupational Safety and Health Administration (OSHA) regulation (1910.134(b)) defines the term as "an atmosphere that poses an immediate threat to life, would cause irreversible adverse health effects, or would impair an individual's ability to escape from a dangerous atmosphere."
Nitrogen is the most common pure element in the earth, making up 78.1% of the volume of the atmosphere [9] (75.5% by mass), around 3.89 million gigatonnes (3.89 × 10 18 kg). Despite this, it is not very abundant in Earth's crust, making up somewhere around 19 parts per million of this, on par with niobium, gallium, and lithium.
At 4000 m, raising the oxygen concentration level by 5% via an oxygen concentrator and an existing ventilation system provides an altitude equivalent of 3000 m, which is much more tolerable for the increasing number of low-landers who work in high altitude. [102]
A confined space is a space with limited entry and egress and not suitable for human inhabitants. Alternative names for a confined space are enclosed space and dangerous space. [ 1 ] An example is the interior of a storage tank , occasionally entered by maintenance workers but not intended for human occupancy.
Pressurized aircraft cabins are typically maintained at 75 kPa, the pressure found at 2,500 m (8,200 ft) altitude, resulting in an oxygen partial pressure of about 16 kPa, which is the same as a 15% oxygen concentration in a hypoxic-air application at sea-level pressure. However, passengers are sedentary and crew members have immediate access ...
The total mass of Earth's hydrosphere is about 1.4 × 10 18 tonnes, which is about 0.023% of Earth's total mass. At any given time, about 2 × 10 13 tonnes of this is in the form of water vapor in the Earth's atmosphere (for practical purposes, 1 cubic metre of water weighs 1 tonne).