We all know that air is mostly nitrogen…79% to be precise. What may not be a common knoweldge is that colorless odorless Nitrogen has led to asphyxiation and fatalities and is a risk particularly for personnel working in confined spaces and personnel utilizing breathing air systems.
According to the Chemical Safety Board (CSB) research there were 80 nitrogen asphyxiation fatalities between 1992-2002. This translates to one nitrogen asphyxiation death every seven weeks. Approximately, 10% of fatalities were due to attempts to rescue person in confined spaces.
Reduced Oxygen concentration (18% or below) in breathing air can lead to asphyxiation.
At 16% Oxygen concentration, may impair thinking and the person may lose coordination.
An 4-6% Oxygen concentration in the atmosphere causes the victim to fall into a coma less than 40-seconds.