The purpose of prospective risk assessments for chemicals is to identify potential risks for humans or environmental compartments like water bodies prior to the use of the substances. This is an important element to reach the Sustainable Development Goal (SDG) 6.3 to minimize the release of hazardous chemicals and SDG 12.4 to achieve the environmentally sound management of chemicals. Only with the knowledge which emissions of hazardous chemicals are relevant, these can be reduced in a goal-oriented manner. Within our study, we challenged the environmental risk assessment for biocides, which is conducted under the European Biocidal Products Regulation 528/2012, and evaluated whether it covers all possible emissions of biocidal active substances from households into wastewater. Thereby, we identified possible limitations of the existing risk assessment concept and yet unidentified possible risks for wastewater treatment plants and receiving water bodies.
For this reason, we established inventories of household products that could possibly contain biocidal active substances in 131 households in selected study sites in Northern Germany. The products that were used in the households were registered with the help of a barcode scanner. The ingredients of these products were evaluated, whether they contained biocidal active substances and whether the specific use of these substances is falling under the Biocidal Products Regulation.
Biocidal active substances were present in all households, even though not all possessed biocidal products, as the majority of observations of biocidal active substances was in washing and cleaning agents and personal care products, but not in biocidal products. Around 64 % of the registered applications of biocidal active substances do not fall under the risk assessment of the Biocidal Products Regulation. These can be active substances present in washing and cleaning agents, which are not assessed or approved for the use as in-can-preservatives. Furthermore, all biocidal active substances present in personal care products are not covered by the risk assessment of the Biocidal Products Regulation.
The results show that gaps exist in the environmental risk assessment of biocidal active substances. The attempt to solve the problem would require an extensive increase of complexity of risk assessments and their aggregation throughout all legislation. From our point of view, a better approach to reduce possible risks by these substances in general would be to limit their use to in fact essential usages. A sustainable use of biocides should thus be promoted to account for the limitations in the environmental risk assessment of these substances. This could be a promising approach to reach the SDGs of minimizing the release of hazardous chemicals.