Cleaning products containing living microorganisms as active ingredients are increasingly being used in household, professional and industrial cleaning applications. Microorganisms can degrade soiling associated with dirt, food residues, and grease by enzymatic and metabolic action and out-compete microorganisms associated with odor problems. Their potential for odor control seems to result in a competitive advantage over conventional chemically-based cleaning products. Moreover, producers of microbial-based cleaning products (MBCPs) claim that their products are less harmful to the environment. These promising prospects have triggered interest from consumer and environmental organizations, professional users, and regulators in understanding if there are also possible negative health and environmental impacts which require attention and how the safety of these products is ensured. Unfortunately, there is little information on these issues in the public domain. Moreover, regulatory oversight in Europe is essentially limited to pathogenic properties in the context of worker protection. Canada, in contrast, has a regulatory framework in place to assess risks to human health and the environment from the manufacture, import and/or use of new microorganisms contained in MBCPs. In the absence of mandatory standards, safety assessment and hygienic practices seem to vary considerably across companies. Recently developed ecolabelling standards are - for the time being - the only option for transparent compliance to minimum standards in terms of safety as well as assessments of manufacturer information by third parties. These standards highlight in particular the need for precise taxonomic information for assessing the pathogenic properties and the need to ensure the absence of potentially harmful microorganisms as contaminants. Ecolabelling standards are, however, voluntary and do not cover all relevant safety issues. In order to develop a more comprehensive set of mandatory standards for health and safety, a number of areas would benefit from further research (e.g. the role in plant pathogenicity and other environmental properties of the microorganisms used; the relevance of chronic exposure to dusts and aerosols containing vegetative cells and spores; the relevance of strains which belong to species known to include opportunistic pathogens and possible hazards for particularly sensitive risk groups). Improved knowledge in these areas will contribute to a predictable level of product safety.