The IBRG Wet-State Preservation Group was created at the Autumn meeting in 2016 and is the logical evolution of the activities of the Polymer Dispersion Group and its activities in developing wet-state preservation methods for polymer dispersion and adhesives. It's objective is the create a cascade of methods suitable for use in providing efficacy data for the registration of biocidal active substances and biocide products intended for the preservation of a variety of materials prior to first use as well as to provide guidance and methods suitable for use by the various industries impacted by set-state spoilage issues.
Polymer dispersions, also referred to as polymer emulsions, latices, latex emulsions, latex dispersions or binders are fine dispersions or suspensions of synthetic polymers in aqueous media. Polymer emulsions are used in a large number of industries for the production of a rapidly increasing variety of routine and specialised products, for example: adhesives, carpet backing compounds, emulsion paints, textile finishing, printing and flocking, textured coatings, glass fibre sizes and binders, industrial finishes, paper and board coating, printing inks, wallpapers, building auxiliaries and cement additives, soil and mineral stabilisation, non-woven fabrics.
Collaborative Testing Programme
The IBRG Polymer Dispersion Group encompasses a wide range of experts representing the polymer dispersion industry, biocide manufacturers and suppliers, private and state research institutes and testing laboratories. The collaborative testing programme of the Group has concentrated on the need to develop a standard method of test that could be used for determining the efficacy of biocides used in polymer dispersions as part of their registration under the EU Biocidal Products Regulation (BPR). A secondary objective is to provide the polymer dispersion industry with a method that will allow the predictive evaluation of biocides used in the products they manufacture.
Eight main collaborative experiments have been carried out dealing with identifying polymer dispersion spoilage organisms, establishing an appropriate standard inoculum and validation of a draft test protocol, A Method for the Evaluation of Biocidal Compounds in Aqueous-Based Polymer Dispersions; Version 5.6-2011/04, April 2011 (document IBRG/PD11/005).
The work leading to the development of the standard inoculum was published as follows:
Gillatt, J.W.: Evaluating Biocidal Efficacy in Polymer Emulsions, Part 1, Establishment of a Recommended Microbial Inoculum, Paint and Ink, Jan/Feb 1995, p. 18 et seq.
Wet-State Bacterial Testing
IBRG has recently completed the development of a standard method for determining the susceptibility of paints to bacterial contamination. The method can be employed to help determine the optimum concentration of in-can preservative required to protect a paint formulation from bacterial spoilage. A summary of the development work was published in The European Coatings Journal in March 2000 and the full method will be published later this year.
In support of the Wet-State Test Method, work is in progress to optimise techniques to ensure both the viability and virulence of test strains used in bacterial challenge studies.
Wet-State Fungal Testing
As a continuation of the Wet-State Bacterial Test development, the Paints Group has recently been investigating methods to examine fungal growth in liquid paint and related materials. Preliminary studies have focussed on tinters and although initial studies looked at the liquid phase of such systems, work is currently directed at developing methods which can help prevent growth on the dried deposits of tinter which are often present in systems which are used to handle the material.
It is well recognised that the hygiene of the paint manufacturing plant has a great impact on the microbiological quality of the final product. For this reason, the group has produced a set of guidance documents for the industry which will be published both on this web site and in a range of trade journals and in a number of languages in 2002.