Category:Response options

Risk assessments for chemical transport and hazard evaluation of potential outflows are integral parts of national response capability for response to major outflows at sea.

It is presumed at present situation, that with the necessary safety precautions having been taken, floating substances can mostly be combated with dispersants or oil recovery vessels and associated booms and skimmers; that sunken substances can be recovered with dredging equipment; and that lost cargoes and sunken ships can be recovered by salvage companies having the appropriate equipment.

However for the most common chemical response categories, there are no recovery techniques for released vapours and gases or for released liquids and solids already dissolved in the sea. Thus, response measures in such cases are limited to restriction of access to the hazardous areas by users of the sea and by the public until the substance naturally dilutes to safe concentration levels when restriction can be lifted.

Thus, concentration reduces as the volume of the affected atmosphere or sea inversely increases.

In all cases computer models can be devised:

• To determine the volume affected by the released mass as a function of elapsed time
• To indicate where measurements might be made
• To indicate where samples might be taken
• To determine the seriousness
• To predict the trajectory
• To determine the mass balance

In case of sunken packages the environmental consequences of subsequent content-release determines the need for recovery, though determination of the solution rate to evaluate possible environmental impact may require experimentation when such information is otherwise unavailable. Submerged and floating packages/ containers should always be salvaged independent of their contents because they are a collision danger to shipping until they strand.

Ships in distress while carrying chemicals, need special attention in national contingency plans, several differing chemicals being in danger of entering the marine environment should the ship sink or break up. Thus, contingency plans should foresee the need to bring such a distressed ship to shelter in order to repair the damage or to unload the cargo or to direct it from the coastline as far as safety, economic and environmental considerations may require.