Safety principles

Rescue work in a hazardous atmosphere is safe only when everybody follows a small number of simple rules, every time. Most fatal accidents in confined spaces involve people who went in to help without protection — and became the next casualties.

Never alone

Work in a hazardous atmosphere is always done by a team of at least two, in sight or in voice contact with each other. Outside the hazard zone a standby team, fully equipped, is ready to enter immediately if something goes wrong.

Entry control

Every entry is recorded: who went in, when, with what cylinder pressure and the expected time of return. The entry control officer keeps track of the time and calls the team back if contact is lost or the planned time is exceeded.

Measure before and during the work

The atmosphere is measured before entry, at different heights (some gases are heavier than air, some lighter), and continuously while people are inside. Conditions can change quickly: a valve may leak, sludge may release gas when disturbed, ventilation may stop.

Know your air supply

Each rescuer knows the duration of their apparatus and watches the gauge. The turn-around point is planned so that the way back, which may be slower and harder, can be completed with a reserve still in the cylinder.

Control ignition sources

In a flammable atmosphere, only explosion-proof equipment is used: lights, radios, fans, detectors. Hand tools are chosen so that they do not produce sparks, and static electricity is controlled by grounding.

Isolate and ventilate

Before planned work in a vessel or a well, the equipment is isolated from all sources of gas and liquid — by closing and locking valves and fitting blind flanges — then purged and ventilated. Measurements confirm the result. A closed valve alone is not isolation.

Communication

Signals are agreed in advance and checked before entry: radio, rope signals, or hand signals for noisy environments. Loss of communication is treated as an emergency.

Decontamination

After work with toxic or corrosive substances, people and equipment are decontaminated before protective equipment is removed, so that the substance is not carried to clean areas or onto skin.

Health and fatigue

Heavy apparatus and protective clothing cause heat stress. Work and rest periods are planned, rescuers drink enough water, and anybody who feels unwell reports it at once. A tired rescuer is a risk to the whole team.

Learn from every incident

After each operation and each drill, the team discusses what went well and what did not. Near misses are reported and analysed in the same way as accidents, because they show where the next accident might happen.