200132 Depletion of Oxygen

Depletion of Oxygen
Report No. 200132

A barge was to be used to store sand, cement and bentonite at a construction site. Prior to being loaded an inspection of the barge took place. It was required to undertake periodical checks of the hull to control water accumulation. A worker was asked to enter the hull and to perform the first inspection.

Unfortunately, as a result of intensive corrosion processes, a significant decrease of oxygen concentration inside the barge had occurred. The man who entered the barge hull was almost suffocated from lack of oxygen. Only the curiosity of a fellow worker instigated a search and he was rescued. Even two hours after the accident, oxygen concentration inside the hull of the barge was still less than the required minimum. When corrosion displaces the oxygen, there is a danger of asphyxiation.
Unconsciousness or death may result very rapidly when there is little or no oxygen, and there is no warning effect. Confined spaces where there may be a deficiency in oxygen must always be ventilated before entering, the air tested and breathing apparatus worn.

Such accidents must be prevented through providing workers with a proper air measurement device. Breathing equipment must also be available for rescue operations. Normal gas masks give no protection against oxygen deficiency. Workers must be properly warned of the danger.