One requirement in the biocides regulation (528/2012/EU) is that the efficacy of the biocidal product has to be demonstrated when applying for approval. It has to be shown that the product really has the intended effect on the harmful organism. How such a requirement will affect the marketing of articles treated with biocides is an interesting question that is discussed in the report. The study aims at giving an overview of different types of efficacy requirements in the biocidal rules but also and in other types of neighbouring regulations.