Corrosive substance due to their capabilities of dissolving greases, proteins or mineral deposits such as limescale inside water pipes. In chemical uses, high chemical reactivity is often desirable, as the rates of chemical reactions depend on the activity (effective concentration) of the reactive species. For instance, catalytic sulfuric acid is used in the alkylation process in an oil refinery: the activity of carbocations, the reactive intermediate, is higher with stronger acidity, and thus the reaction proceeds faster. Once used, corrosives are most often recycled or neutralized. However, there have been environmental problems with untreated corrosive effluents or accidental discharges. Corrosive substance A
Chemical safety assessment Restriction of Chemical substances) in which hazard and exposure data are considered together to assess the risk of a substance. Chemical safety assessment Chemical safety assessment (CSA) "has to be performed by registrants for substances manufactured and imported in quantities starting at 10 tonnes per year and by downstream users if their uses are not addressed by their supplier," according to REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) legislation. The CSA includes the evaluation of all available relevant information in order to assess risks arising from the manufacture and/or use of a substance. The process needs to be documented