Molds, mildew and other fungi are of major concern to paper and book conservators because of the damage these organisms can do to manuscripts, books, and paper works of art. This is particularly a problem in those museums, libraries and archives where inadequate environmental controls create conditions of high relative humidity and high temperatures which are especially conducive to the growth of mold and mildew. The two most common fungicides used to control mold and mildew are thymol (isopropyl-meta-cresol) and o-phenyl phenol (ortho-phenyl phenol, Dowicide 1). These fungicides are used in fumigation and humidification chambers, in alcohol solutions, and in starch paste adhesives.