There is a recognised need for antimicrobial additives in plastics and all types of surface coatings to maintain their integrity and appearance. The current available laboratory test methods for determining the microbial resistance of plastics do not always provide a good indication of performance and some could be open to misinterpretation. In addition, the use of additives for claims of antibacterial activity of finished plastics needs careful consideration in light of the potential risk to benefit ratio.
Dean Nichols, Group market development manager of Thor describes the background to these issues and explains how the implementation of the forthcoming section of the European Biocidal Products Directive will have a significant impact on all antimicrobial additives, including biostabilisers for plastics.
This contamination can take the form of visible surface growth, discolouration or malodours and in the worst case such growth can lead to the degradation and failure of decorative or functional properties of a plastic. These include its strength and flexibility, electric insulation resistance or transparency.