Physical and Chemical Properties of Nitrogen

As mentioned during the introduction, nitrogen is a colourless, odourless, tasteless, non-flammable gas, hence it does not support combustion. Having said that, a tank full of nitrogen (which replaces the oxygen content to below 8% volume) is therefore protected from any fire hazards. Additionally, nitrogen being an inert gas, will not allow chemical cargoes found inside the tank to react with the external atmosphere and therefore keeps the cargo tank isolated.

The due point of nitrogen is -40° Celsius and hence this gas will drive away all the moisture vapour found inside the tank which, if left there, may contaminate and adversely affect the cargo. Due to this reason, nitrogen is termed a drying gas.

Although nitrogen in itself is not toxic, its presence does not support life. The reason for that is that a tank that is purged with nitrogen, experiences a reduction in oxygen level to below 21% which is not safe for life. With that said, an uncontrolled entry will most definitely result in casualty or death depending on the oxygen level. A tank that has Nitrogen inside and any adjacent compartments should be regarded as an Enclosed Space.