Search results
Results from the WOW.Com Content Network
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.
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."
Workplace air that is polluted with fine particulate matter or noxious gases but that contains enough oxygen (in the US, this is ruled to be a concentration above 19.5%; in the Russian Federation, above 18% [citation needed]), can be rendered safe via air-purifying respirators. Cartridges are of different types, and must be chosen correctly and ...
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.
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 ...
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 abundance of the chemical elements is a measure of the occurrences of the chemical elements relative to all other elements in a given environment. Abundance is measured in one of three ways: by mass fraction (in commercial contexts often called weight fraction), by mole fraction (fraction of atoms by numerical count, or sometimes fraction of molecules in gases), or by volume fraction.
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.