JAIC 1986, Volume 25, Number 1, Article 5 (pp. 49 to 55)
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Journal of the American Institute for Conservation
JAIC 1986, Volume 25, Number 1, Article 5 (pp. 49 to 55)


John H. Haines, & Stuart A. Kohler


TO BE EFFECTIVE in stopping fungus growth in moldy paper the fumigant would have to produce no growth (0) across all seven species under all conditions. The “dry” colonies on “paper” are analogous to the fungus colonies which would survive on moldy paper and the “dry” colonies on “agar” are analogous to those which could be spread from moldy paper.

The inability of OPP fumigation to render all of the fungus colonies inviable after three or even ten days of exposure indicates that it is not an effective method of treating moldy books and papers. Similar results were obtained for thymol in this study. The results obtained here are in contrast to those obtained by Florian (1975) in a different set of tests using thymol as a fumigant. The Florian study indicated that the fumigant was fungicidal for the fungi tested.

There are, however, significant differences between the two studies; the fungus species, the preparation of the fungi before fumigation and the amount of fungus spores in a sample. The present authors used very large amounts of dried spores, instead of smaller amounts of spores and hyphae for their tests. They believe that this accounts for the difference between the two studies.

The percentage of spores killed in the present study was high. Perhaps it was more than 99%, but that is an almost insignificant loss to a fungus which can produce hundreds of thousands of spores in a small colony started from a single spore.

To rid books and paper of mold problems by a non-destructive chemical application with a minimum of human contact would appear to be an attractive course of action. The problems with this are that most fungicides are either hazardous gasses which pose a health risk to the user or solutions which may damage cellulosic material. Even if the perfect, non-hazardous, non-destructive fungicide is found, there is a fallacy in the “one-shot cure” of fungus problems. Any “cure” which does not leave a residual toxin and which does not change the conditions for fungus growth is a temporary cure.

A second fallacy is that dead fungus spores are not a health hazard. If a spore is an allergen when it is viable it is still an allergen when it is nonviable, but if it was treated with a toxin it now has a coating of toxin in addition to its allergenicity.

It appears that there is no procedure in use at the present time which will allow paper to be stored in high moisture conditions and remain immune to fungus attack. Every effort to maintain lower relative humidity of collection materials and storage areas will be rewarded by diminished fungus growth.


MARY- LOU FLORIAN, for her helpful discussions of her studies and Ira F. Salkin, Infectious Disease Center, New York State Health Department, for the use of his cultures.

Copyright 1986 American Institute for Conservation of Historic and Artistic Works