COLLABORATIVE INVESTIGATIONS OF LABORATORY TEST METHODS FOR EVALUATION OF THE GROWTH OF PINK YEASTS ON PAINT FILMS

Since the pink yeasts Rhodotorula and Sporobolomyces often colonise pa int films, showing resistance to a number of fungicides, a series of i nterlaboratory investigations to evaluate methods for determining the resistance of paint films to pink yeasts was undertaken by members of the Paints Project Group of the International Biodeterioration Researc h Group (IBRG). Three systems were examined: a moist vermiculite bed t echnique and two exposure regimes using a flat panel/humidity cabinet. The most effective was 'low' severity exposure of panels in the humid ity cabinet. Although the panels used in this method, were subject to adventitious contamination by moulds, the studies demonstrated that pi nk yeasts can grow on paints containing commercial fungicides and this system can therefore be used for screening new fungicidal products.