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10 Appendices

The cause

Because of this, contamination may possibly go unnoticed, The cause of contamination or off-speciication can be
while an off-speciication likely will not, unless there is a inluenced by many factors and often more than one is

problem with the testing, as will be described in this article.relevant in an investigation. Contamination is sometimes

The amount of contaminant (i.e. from coatings or caused by things such as rust, coatings, residuals in piping,
seawater) or damaged product (i.e. from degradation or remnants of previous cargoes in the tank, water ingress, and

oxidation) required to cause off-speciications or become biological growth. Off-speciications that are not due to

otherwise noticeable varies greatly depending on the cargo contamination, on the other hand, can be caused by changes
and its context. For example, to cause a hypotheticalin the chemistry of the material such as degradation,

cargo of 1000 MT pure vinyl chloride monomer, or VCM,oxidation, and polymerization.

a plastics ingredient, to fail speciication for non-volatile Helping to determine cause, contractual speciications
residue (often set at 15 ppm), 15 kg of residue from sources for chemicals are designed to be speciic to the properties

such as rust or paint would need to be suspended in the of that material and are often geared towards monitoring

tank while representative sampling occurred. Similarly, for suspected vestiges of production, storage, and transport.
the same hypothetical cargo of pure vinyl mono chlorideAdditionally, speciications for fuels often include parameters

to fail speciication for the precursor compound ethylene relating to performance and emissions. Regardless, most of

dichloride, or EDC (often set at 5 ppm), around four litres of the root causes of off-speciications and contaminations
EDC would need to be introduced into the cargo. In perhaps are shared between the two cargo categories of fuels and

a more alarming example, it is possible that less than one chemicals, and whatever the commodity and cause of

litre of fuel oil could cause a hypothetical 1000 MT of damage may be, careful sampling and laboratory tests are
benzene to fail speciication for sulphur (often set at 1 ppm).required to understand the situation, so a fair conclusion can

be reached.

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