"A Hazardous and Noxious Substance is a term used to describe a substance other than oil which, if introduced into the marine environment is likely to create hazards to human health, to harm living resources and marine life, to damage amenities or to interfere with other legitimate uses of the sea ... Consequently chemical spills occur at a much lower frequency than spills of oil. However, the consequence of a chemical spill can be more wide reaching than that of oil." (Quoted from article)