Some materials when damp or soaked with paints, oils of vegetable origin in particular can ignite
without external application of heat.
Auto ignition temperature of a material is the temperature at which a flammable material will ignite
without initiation of a spark or flame.
Spontaneous combustion is the process of
gradual increase in temperature of a material as a
result of oxidation, without drawing any heat
from its surrounding. This process finally results in
ignition of the material concerned.
Lagging on steam pipes or cotton rags if soaked
with oils and or paints and stocked in a warm area
without ventilation is prone to spontaneous
combustion. This oil begins to oxidise and produces
heat in the process. This heat causes the remaining
oil to oxidise faster and produce still more heat that
will start building up around the rag. This in turn
will ignite any other flammable substance resulting
in a major fire.
Petroleum liquids when heated sufficiently will ignite without the application of a naked flame. When
fuel or lube oil under pressure sprays onto a hot surface, it will get hotter and will auto ignite as a result.
Any oil saturated lagging must be removed at once and safely disposed of.
Oily rags, rags used for cleaning paint drums or soaked in paint thinners, saw dust impregnated
with oil should be stored in a safe location in covered containers and disposed of in a proper way as
early as possible.
Oil feeder piping need attention to avoid oil being sprayed from leaks.
Good housekeeping is the only effective answer to prevent fire due to spontaneous combustion and
auto ignition.
Cotton rags used for mopping cargo tanks, which have carried any vegetable oil as last cargo, are
extremely prone to spontaneous combustion.
3.
Electrical Circuits and Electrical Equipment
Electricity is a safe and convenient source of power if the equipment concerned is properly insulated
and wired. If worn-out, misused or poorly wired electrical energy is converted into heat and the
equipment concerned becomes a source of ignition and thus a fire hazard.
Only approved electrical equipment for shipboard use that will stand the strenuous conditions at
sea are installed and/or used on board a ship.