Chemical composition of pellets spilled in Galicia

According to a brief report released on January 9 by the Xunta de Galicia, the pellets that were spilled last December 8 from the Liberian-flagged ship Toconao in bags labeled "UV9000 light stabilizer" imported by Bedeko Europe and manufactured in India by the Coraplast company (yes, much of the plastic consumed in Europe is produced in Asia) have the following composition. Their matrix is the most common polymer, polyethylene, completely harmless, BUT they contain between 10 and 13% of a chemical additive used as an ultraviolet stabilizer (as expected given the labels on the bags). This additive called UV622 (CAS number 65447-77-0) is in turn a non-biodegradable polymer with two components, succinic acid, an organic acid without toxicological problems, and a synthetic substance from the family of hindered amines that gives it its antioxidant properties (CAS number 52722-86-8). This substance is classified by the European Chemical Agency as a substance with chronic toxicity (that is, it would only be toxic in prolonged exposure, which is not the case for short-term cleaning tasks), and irritating to the eyes (so this precaution must be taken when cleaning). According to this same dossier, its toxicity to Daphnia (an aquatic invertebrate that is used as a model to assess the toxicity of a substance) would have an EC50 (concentration that causes 50% mortality) of 160 mg/L, which would categorize it as low toxicity.

In the safety data sheet of UV622 it is stated a toxicity for Daphnia of EC50=25 mg/L, which in contrast to the previous one would classify it at a medium level of aquatic toxicity. In any case, it is not expected that these levels will be reached on open coasts.

None of the above documents provides experimental information on toxicity in marine organisms. The ECOTOX group is currently conducting toxicity tests with representative models of marine phytoplankton and zooplankton to fill this gap, and we will shortly publish the results obtained here.