present invention relates to a method for imparting biocidal protection to clothing or other fabrics which comprises contacting the clothing or other fabrics with a biocidally effective amount of pyrithione acid or salt thereof or combinations thereof in an automatic laundry dryer also disclosed is a transfer substrate containing a biocide consisting essentially of pyrithione acid or salt thereof or combinations thereof said biocide being present in or on said transfer substrate in an amount sufficient to impart antimicrobial activity to clothing or other fabric in an automatic clothes dryer application_number US 67946791 A description the pyrithione employed in the present invention is preferably selected from the group consisting of pyrithione acid sodium pyrithione zinc pyrithione copper pyrithione aluminum pyrithione magnesium pyrithione pyrithione disulfide 2 2 39 dithiobis pyridine 1 1 39 dioxide chitosan pyrithione and combinations thereof particularly preferred pyrithione salts useful in the present invention include sodium pyrithione zinc pyrithione pyrithione disulfide and chitosan pyrithione the sodium pyrithione suitably employed in the process of the present invention is a well known commercial product and is commonly made by reacting 2 chloropyridine n oxide with nash and naoh as disclosed in u s pat no 3 159 640 the disclosure of which is incorporated herein by.