10. Entering and working in enclosed or confined spaces
10.1. General provisions
10.1.1. All enclosed or confined spaces should be considered unsafe for entry
until proven otherwise.
10.1.2. If there is an unexpected reduction in or loss of ventilation, in spaces
which are usually ventilated by whatever means, then those spaces should also be
considered as dangerous.
10.1.3. Any enclosed or confined space may have an atmosphere deficient in
oxygen, and/or contain flammable or toxic fumes, gases or vapours, thus presenting a
major risk to health or life for anyone entering it. Areas in which an unsafe atmosphere
is present or can arise include cargo holds, double bottoms, cargo tanks, pump rooms,
compressor rooms, fuel tanks, ballast tanks, cofferdams, void spaces, duct keels, inter-
barrier spaces, sewage tanks, cable trunks, pipe trunks, pressure vessels, battery
lockers, chain lockers, inert gas plant scrubber and blower spaces and the storage rooms
for CO2, halons and other media used for fire extinguishing or inerting.
10.1.4. Such enclosed or confined spaces should not be entered except upon the
explicit instruction of the master or the responsible officer. If a deficiency of oxygen or
the presence of toxic gases, vapours or fumes is suspected in any space, then that space
should be considered dangerous.
10.1.5. The crew should be drilled periodically in confined spaces rescue and
medical first aid.
10.2. Precautions on entering dangerous spaces
10.2.1. Before a space is entered, the following precautions should be taken, as
appropriate, to make it safe for entry without the need for breathing apparatus, and to
ensure that it remains safe whilst seafarers are inside:
(a) a competent person should make an assessment of the space and a responsible
officer should be appointed to take charge of the operation;
(b) the potential hazards should be identified;
(c) the space should be prepared and secured for entry;
(d) the atmosphere should be tested;
(e) a "permit-to-work" system should be used (see Chapter 4);
(f) entry procedures should be established and followed;
(g) continuous ventilation should be maintained throughout.