What to consider when choosing a biocide?
Anywhere there is moisture and a potential food source, there is potential for microorganism growth. Many locations, processes and products offer ideal conditions for microbial growth that can lead to major health threats to people and animals, enormous economic losses, or simply unpleasant and inhospitable surroundings.
Industrial biocide uses are essential to the economic health of an industrialized society by extending the in-use life of manufactured goods and protecting equipment. Material preservation results in decreased energy and natural resource consumption and waste generation, producing significant economic and societal benefits.
The paint industry has long been aware of the problems of microbial attack on painted surfaces. Microbial growth can lead to both aesthetic and physical degradation of the coating or painted surface. In addition to the obvious aesthetic effects of mold, mildew and algae growth, physical deterioration by their enzymes can lead to physical degradation. This degradation can include an increase in porosity of the surface coating or a loss of adhesion to the substrate. Moisture penetration can lead to fungal decay of the underlying wood. Biodegradation is not limited to the surface coating or dry paint films; it can also occur during production and storage of the paint.
It is important to take a holistic approach when selecting a biocide. The characteristics of microbial communities are a distinct and direct reflection of the environment in which they exist. Finding a suitable biocide to prevent the degradation demands careful consideration of different aspects. One of the main goals is to select dry film biocide to achieve broad-spectrum and long-lasting protection of the paint film. One of the challenges is that relatively few biocide active agents are available, and those actives must simultaneously meet multiple requirements. Evaluation of fungicides and algaecides in the context of a paint formulation biocide program invariably involves outdoor exposure testing - especially, when it is desired that the results have relevance for more than one geographical region. In addition to consideration of the properties, microbial spectrum and regulatory status of the biocide active agents, there are procedural variables that must be considered. These include the type of substrate to be coated, the coating application method, the panel orientation and direction, the number of replicates, and the inclusion of appropriate controls.
Globally Harmonized System
Local biocide regulations and environmental public awareness considerations often limit the selection of available active agents or limit the amount of these actives that can be present in a coating. In Europe the regulations which need to be taken into consideration are REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), CLP (classification, labelling and packaging of substances and mixtures) and the Biocidal Products Regulation (BPR, Regulation (EU) 528/2012). The first two concern all chemicals used and sold in Europe whereas the last one concerns specifically biocidal products, which are used to protect humans, animals, materials or articles against harmful organisms like pests or bacteria, by the action of the active substances contained in the biocidal product. BPR aims to improve the functioning of the biocidal products market in the EU, while ensuring a high level of protection for humans and the environment.
Since 1st September 2015 it hasn't been possible to supply a biocidal product on the EU market, unless the product is included in the Article 95 list of the approved biocides (see the full list) All biocidal products require an authorisation before they can be placed on the market, and the active substances contained in that biocidal product must be previously approved. There are, however, certain exceptions to this principle. For example, biocidal products containing active substances in the Review Programme can be made available on the market and used (subject to national laws) pending the final decision on the approval of the active substance (and up to 3 years after). Products containing new active substances that are still under assessment may also be allowed on the market where a provisional authorisation is granted.
The BPR aims to harmonise the market at Union level; simplify the approval of active substances and authorisation of biocidal products; and introduce timelines for Member State evaluations, opinion-forming and decision-making. It also promotes the reduction of animal testing by introducing mandatory data sharing obligations and encouraging the use of alternative testing methods.
The approval of active substances takes place at Union level and the subsequent authorisation of the biocidal products at Member State level. The authorisation can be extended to other Member States by mutual recognition. However, the new regulation also provides applicants with the possibility of a new type of authorisation at Union level (Union authorisation).
In summary, long-term, broad-spectrum microbial control on painted surfaces can be achieved by careful selection of biocide active agents, including consideration of their properties, microbial spectrum and regulatory status. With the help of our European supplier, we are able to assist you with your analysis and even offer you customized solutions, training and lab services to serve your specific needs.