<Li> Acute aquatic toxicity means the intrinsic property of a material of causing injury to an aquatic organism in a short - term exposure . Substances and mixtures of this hazard class are assigned to one of three toxicity categories on the basis of acute toxicity data: LC (fish) or EC (crustacean) or ErC (for algae or other aquatic plants). In some regulatory systems these acute toxicity categories may be subdivided or extended for certain sectors . </Li> <Li> Chronic aquatic toxicity means the potential or actual properties of a material to cause adverse effects to aquatic organisms during exposures that are determined in relation to the lifecycle of the organism . Substances and mixtures in this hazard class are assigned to one of four toxicity categories on the basis of acute data and environmental fate data: LC (fish) or EC (crustacea) or ErC (for algae or other aquatic plants) and degradation or bioaccumulation . </Li> <P> The GHS approach to the classification of mixtures for health and environmental hazards is also complex . It uses a tiered approach and is dependent upon the amount of information available for the mixture itself and for its components . Principles that have been developed for the classification of mixtures, drawing on existing systems such as the European Union (EU) system for classification of preparations laid down in Directive 1999 / 45 / EC . The process for the classification of mixtures is based on the following steps: </P> <Ol> <Li> Where toxicological or ecotoxicological test data are available for the mixture itself, the classification of the mixture will be based on that data; </Li> <Li> Where test data are not available for the mixture itself, then the appropriate bridging principles should be applied, which uses test data for components and / or similar mixtures; </Li> <Li> If (1) test data are not available for the mixture itself, and (2) the bridging principles cannot be applied, then use the calculation or cutoff values described in the specific endpoint to classify the mixture . </Li> </Ol>

Ghs stands for the globally harmonized system of