D. Oxygen Deprived
Oxidation of coal will consume oxygen, so the oxygen
concentration in coal loaded holds will be lower than normal
level. The oxygen concentration will depend on the degree of
oxidation, extent of methane emission, ventilation condition,
air tighten condition of the hatch cover. Normally the oxygen
concentration significantly drops during the first week,
followed by a trend of gradual decline. The trend in the decline
of concentration differs with not only the qualities of coal but
also other factors, including the void space in the hold and the
air tightness level of the hatch cover. In some cases shown that
oxygen concentration in coal carried holds fell to 1% or even
less during two weeks of transit. Oxygen is essential
requirement for life, human being will lost his life when long
time exposed to a environment where the oxygen concentration
less than 18%, so it is very dangerous to enter the cargo hold
without sufficient ventilation.