Exam Question

(a) An Enclosed Space is defined as any space that is enclosed. An enclosed space has a risk of death or serious injury from hazardous substances or dangerous conditions such as lack of oxygen, toxic gas or other vapour, Limited openings for entry and exit, Unfavourable natural ventilation and is not designed for continuous worker occupancy
Examples of enclosed spaces on-board ship are
Ballast tanks, Fuel oil tanks, Pump rooms, Cargo holds, double bottoms, lube oil tanks, Void spaces, Engine crankcases, BOW Thruster spaces, Battery lockers, Boilers, Cargo tanks, Double hull spaces, Sewage Tanks, Cofferdams, Inter barrier spaces, CO2 rooms, Paint lockers, Fresh water tanks, Spaces affected by chemical spill, Pressure vessels, Gas bottle storage lockers, spaces affected by fire, compressor rooms, duct keels, chain lockers, hollow spaces.
(b) An enclosed space contains lack of oxygen or contains flammable or toxic gases. it is important to take samples at the top, middle, & bottom to locate varying concentrations of gases & vapours. Highly concentrated gases can collected at the top or bottom of a confined space depending on whether they are less or more dense than air. Dilute gases & vapours in the ppm range distribute evenly throughout a confined space. It is important to sample at a distance from the opening because air supply near the entrance can give a false sense of adequate oxygen presence.