It is dangerous to spend time in rooms on board ship or tanks which are closed off to the outside air for long periods of time, or in which toxic or explosive gases may occur. Entering such confined spaces without precaution can result in accidents entailing serious risk to health or, in extreme cases, death.
Typical hazards include:
1. potentially explosive gases or vapours
2. toxic gases or vapours
3. oxygen deficiency
Gas detection instruments and systems are used to determine the type and extent of the hazard.
