• The List of Marine Pollutants in Appendix B lists materials known to kill or retard the growth of marine life.
• Materials classified as severe marine pollutants only need to make up 1 percent by weight for the mixture/solution to be considered a marine pollutant, in contrast to at least 10 percent for other marine pollutants.

The List of Marine Pollutants can be found in Appendix B to 172.101, immediately following the List of Hazardous Substances and Reportable Quantities. It lists materials that are known to kill or retard the growth of marine life.

Severe marine pollutant (Hazmat)

Materials identified by the letters “PP” in Column 1 are considered “severe marine pollutants.” That means they must only make up 1 percent (by weight) of a mixture or solution for the mixture or solution to be considered a marine pollutant.

All other listed marine pollutants not marked with “PP” must be present in a concentration that equals or exceeds 10 percent (by weight).

Example: A solution weighing 10 pounds would have to contain one pound or more of allyl bromide to be considered a marine pollutant. On the other hand, a solution weighing 10 pounds would only have to contain 0.1 pound of Aldrin (a severe marine pollutant) to be considered a marine pollutant.

Because these materials pose a substantial risk to the marine environment, specific requirements have been established to ensure that they are properly packaged and identified when offered for transportation by vessel.

Marine pollutants transported by water are subject to all the applicable requirements in any size packaging. Marine pollutants transported by highway, rail, or air are subject to the requirements only when transported in bulk packages.