|Substance Group: Zeolite P and -X|
The synthetic zeolites A, P and X (sodium aluminium silicate) are used as builders in deter-gent powders and tablets for water softening in the washing process. In the first phase of the HERA project, an environmental risk assessment was carried out for Zeolite A, which repre-sents, by volume, the most heavily used zeolite type. Based on the calculated PEC/PNEC ra-tios which are below 1 (RCR < 1), no cause of concern was indicated for any of the environ-mental compartments, i.e. water, sediment, soil and sewage treatment plants (STP). In order to extend the environmental risk assessment to all zeolite types used in detergents, additional studies into the aquatic and terrestrial toxicity of zeolites P and X were commissioned. The data obtained showed that the ecotoxicological profile of all zeolites used in detergent appli-cations is comparable. Based on the enlarged data set a revised environmental risk assessment for the total zeolites used in detergents was carried out. Again, RCR values <1 were obtained for all environmental compartments. The favourable outcome of this environmental risk as-sessment and the knowledge about the long-term fate of zeolites, which ultimately turn into natural soil constituents (e.g. clays), provide a sound basis for the conclusion that the use of zeolites in detergent products does not pose a risk to the environment.