International Biodeterioration Research Group Paints Working Group
International Biodeterioration Research Group Paints Working Group
The International Biodeterioration Research Group (IBRG) was originally founded under the auspices of the Organisation of Economic Co-operation and Development (OECD), Paris in 1968. Its membership is made up predominantly of microbiologists from industrial users of biocides, biocide manufacturers, testing laboratories from both the private and government sector and academic institutions. IBRG holds two meetings a year each usually organised by one of the member organisations, most recently in Newark, USA hosted by the Troy Corporation.
Currently the officers of IBRG are:
President: John Gillatt, Thor Chemicals (UK) Limited.
Vice-president: Jenny Lunenburg, Akzo Nobel Decorative Products, Sassenheim.
General secretary: Pete Askew, Industrial Microbiological Services Limited.
Treasurer: Colin Hunter, Building Research Establishment Limited.
The Paints Working Group is one of the currently four working groups of IBRG, the others dealing with plastics protection, biodegradable plastics and leather. In addition the organisation has a technical plenary for the discussion of possible new projects.
The main objectives of IBRG are in the field of test method development and work to investigate basic principles of biodeterioration. These objectives are met in a number of ways. First, by discussion at the meetings; second, by carrying out and reporting on individual laboratory investigations and, most importantly, by organising,performing and reporting on collaborative experimental work or round robin testing.
The IBRG Paints Working Group
The Paints Working Group of the IBRG is one of the oldest of the organisation's working groups and has and is carrying out work in a number of areas.
Dry-film fungal testing
From the mid-1970s for a period of more than ten years a large number of projects were performed. Their objectives were to study all aspects of the growth of fungi on applied surface coatings and to develop a standard method of test. The desire was to produce a test which would allow the in-use fungicidal performance of paints to be evaluated in the laboratory.
Following extensive laboratory trials during which comparisons were made between filter paper/agar plate tests and solid substrate/humidity chamber methods a large field trial/laboratory comparison took place. Panels were exposed at a number of outdoor sites and the growth compared with similar panels exposed in a laboratory test chamber. Close correlation was found between the two methods of test. The results of this work were published in JOCCA and reported to the committee of the British Standards Institute. As a result, the IBRG humidity chamber test was accepted as BS3900 Part G6.
Further work is planned on development of a rapid efficacy test method.
Dry-film algal testing
A similar process has been followed for the laboratory evaluation of paints intended to be resistant to algal growth. Various laboratory techniques were investigated and a vermiculite bed method where test panels are laid on a moist substrate (vermiculite),inoculated with algae and incubated with standard illumination was developed.
Field trials in which panels are being exposed at a number of external locations and the results compared with similar panels tested according to the IBRG laboratory method are currently taking place.
Wet-state bacterial testing
The third IBRG Paints Working Group project has the objective of developing a laboratory test to enable comparisons of wet-state biocides in paints and to investigate the resistance of such products to bacterial infection. The group has just carried out a large statistically designed comparison, resulting in their internal publication of a Draft 5 Test Method.
The method involves addition of biocidels to supplied preservative-free paint or a standard paint followed by three or more inoculations with a standard mixed bacterial suspension. At specified periods after each inoculation the performance of the biocide is evaluated by determination of surviving organisms using traditional methods or proven electrochemical techniques, e.g. impedance measurement.
The Draft 5 Test Method was discussed at the recent IBRG meeting in Newark, USA and it is expected that this will be published shortly with a final validation experiment being undertaken.
Testing of polymer emulsions
The final IBRG Paints Working Group is dealing with the testing of biocides in polymer emulsions and of polymer emulsions themselves. The work is similar to that of the wetstate bacterial paint testing project and has also recently published, internally, a Draft 5 Test Method. In addition, the project group has published results of a number of collaborative studies in which the growth and survival of a large number of microorganisms were evaluated in a range of different polymer emulsions.
As with the wet-state paint project the polymer emulsion project's Draft 5 Test Method was discussed at the Newark IBRG meeting and further validation tests are planned.
Future IBRG meetings
IBRG meetings have been planned well into the next century with venues in Eire, the UK, Denmark,Germany, Norway and Switzerland.
In Spring 1998 IBRG meets at the Grand Hotel, Malahide, near Dublin from 15-17 April with the Olin Corporation as hosts. The Autumn 1998 meeting will be in Chester from 9-11 September hosted by Thor Chemicals (UK) Limited.
Further details of the work of the IBRG Paints Group can be obtained from the General Secretary of IBRG: Pete Askew, IMSL, Pale Lane, Hartley Wintney, Hampshire RG27 8DH. Telephone: +44 (0) 1252 627676; Fax: +44 (0) 1252 627678; E-mail: peter.askew@imsl-uk.com
