The "hygienic surface" concept has become an issue of growing commercial interest. The control of harmful micro-organisms in the community may incur costs exceeding 2 billion euro per annum and collateral costs from illness and product spoilage could far exceed this value.
Avoiding infection from surface contact is vital in particular environments, for example:
Potential methods of controlling microbial contamination range from easy cleanable surfaces, through biocide impregnated surface films, to the advanced technologies of photo-activated anti-microbial coatings. However there is no consensus as to the efficiency of these approaches and their robustness to in-service life challenges. Further, although there are a number of techniques for quantifying bacterial contamination on surfaces, their effectiveness needs to be established and standard test procedures developed.
The problems surrounding production of hygienic coatings are exacerbated by legislation (eg the EC Biocidal Products Directive), designed to restrict the availability and use levels of antimicrobial additives.
A recent report by Freedonia concluded that US demand for disinfectant and antimicrobial chemicals will reach £300 M by 2005. Paints and coatings are predicted to remain the largest market for antimicrobial additives, supported by the trend toward water-based and low-solvent coating formulations which require greater antimicrobial protection.
Although a large growth is predicted in antimicrobial chemicals, there is also a drive to use mechanical processes, such as ultraviolet radiation: this arises out of fears of counter-productivity of over-using disinfectants in cleaning operations.
In the UK, 9% of hospital patients leave hospital with an infection acquired during their stay: as a result at least 5,000 of them will die every year. Furthermore, three-quarters of doctors believe that hospital hygiene rules are routinely broken
Another hugely important area is food safety: the European Commission has launched its latest funding: one programme area (worth euro 600M) will concentrate on food safety and health risks.
In addition, the UK government is to put £42 M towards the advancement of measurement technology, including the measurement of proteins and bacteria.
PRA has already undertaken a project on formulation guidelines for microbial resistant coatings. Biocidal additives are usually incorporated into coating formulations to improve the service life of coatings used to protect structural materials from environmental degradation. Such biocidal additives are potentially toxic and their use if subject to increasingly tight regulation. However, some of the raw materials commonly used in coating formulations have intrinsic inhibitory properties, and this project aimed to quantify the microbial biological activity of the raw materials, in order to provide opportunities for formulating coatings with the necessary film resistance to spoilage, whilst using the optimal amount of biocidal additive.
Hygienic coatings must:
Hygienic coatings are not a defined category. Howeve, the field has high growth potential and is subject to enforced change because of stringent restrictions to be placed on biocidal additives and fears of further restrictions to come.
New, novel technologies and materials are available, such as:
These changes indicate a need for new research and development for both coatings and cleaning regimes. The properties required by a good hygienic coating are also of interest to many other coating applications, including:
Further information on the Special Interest Group can be found here. Alternatively, email the Group Administrator.
PRA has experience and expertise in a number of areas related to the topic of hygienic coatings, including:
Other services of relevance include: