To determine if you need oxygen depletion monitoring, a risk assessment of the area and activities should be carried out. If the risk assessment identifies that in the event of a worst-case scenario oxygen levels would deplete to below 19.5% O2, you require an oxygen monitor. However, a required risk assessment often does not cover specific areas where a leak may occur (such as directly next to LN2 storage vessel) and even in situations in which oxygen depletion does not reach life-threatening levels, the effect of oxygen starvation on the health of working personnel is still a major health and safety concern.

Oxygen enrichment poses a severe fire hazard. An oxygen concentration of 23% or above is regarded as dangerously enriched, meaning materials catch fire more easily and burn more intensely. Therefore, oxygen monitors are recommended.