Prevention and treatment of mold in library collections with an emphasis on tropical climates: A RAMP study: 5. Fungicides and fumigation

Prevention and treatment of mold in library collections with an emphasis on tropical climates: A RAMP study

Preface

Acknowledgements

1. Introduction

1.1 Climate

1.2 Materials

1.3 Modifying the environment

Literature cited

2. Mold

2.1 Structure of mold

2.2 Environmental and nutritional factors in growth and survival

2.2.1 Temperature

2.2.2 Moisture

2.2.3 Nutrients

Literature cited

3. Implications for library materials

3.1 Vulnerability of materials

3.1.1 Paper - cellulose, sizes, coatings

3.1.2 Bookcloth

3.1.3 Leather

3.1.4 Adhesives

3.1.5 Film and related materials

3.2 Environmental factors

3.2.1 Circulation

3.2.2 Relative humidity

3.2.3 Temperature

Literature cited

4. Prevention

4.1 Building design and modification

4.1.1 Location

4.1.2 Structural considerations in environmental modification

4.2 Interior modifications in existing facilities

4.2.1 Location of stack and storage areas

4.2.2 Stack arrangement

4.2.3 Localized environmental modification

4.2.4 Creating microclimates in cabinets and cases

4.3 Stack maintenance

Literature cited

5. Fungicides and fumigation

5.1 Fungicides

5.2 Fumigation

5.3 Toxicity of fumigants

Literature cited

6. Treatment

6.1 Small outbreaks - localized high relative humidity

6.1.1 Books

6.1.2 Unbound materials (documents, maps, works of art on paper)

6.1.3 Photographs, negatives and microfilm

6.1.4 General area

6.2 Moderate outbreaks - Major and prolonged periods of high humidity or minor flooding

6.2.1 Books

6.2.2 Unbound materials

6.2.3 Photographs, negatives and microfilm

6.2.4 General area

6.3 Major outbreaks - Major flooding and prolonged exposure

6.3.1 Priorities and planning

6.3.2 Prevention of mold growth on site

6.3.3 Freezing

6.3.4 Drying

Literature cited

7. Equipment and supplies

7.1 Monitoring equipment

7.2 Prevention

7.3 Treatment

7.4 Emergency treatment

8. Selected bibliography

5. Fungicides and fumigation

Most librarians, archivists and museum personnel share a conviction that mold must be killed. It is perhaps more appropriate and effective to concentrate on prevention, inhibition and removal. As noted earlier, molds are admirably equipped for survival. Even a kill ratio of 99% "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."¹ Fungicides and fumigants broad ranging enough and powerful enough to achieve a 99% mortality for fungi are now known to be toxic to man as well. In considering the use of fungicides and fumigants for the prevention or treatment of mold growth, two basic facts should be kept in mind:

- All biocides are chemically reactive, i.e. they are capable of reacting with and altering materials to which they are applied.

- All biocides have some level of mammalian toxicity.²

The traditional chemical approach to biodeterioration involves two strategies. One strategy, fumigation, interferes with the vital activities of the organism. The other strategy, topical application of fungicides to an object, interferes with their consequences, that is with the chemical reactions of the organism and its substrate. The number of compounds in use today is fairly limited. They include certain metal derivatives, organic chemicals (of which the phenols are the most common), and certain organometal compounds.³ While there is a certain amount of interest in, and testing of more exotic techniques, including irradiation and the use of ozone, "we must not place too much reliance on the hope for brand-new biocidal agents as the solution to the problem."⁴ Both irradiation and ozone have been found to be damaging to certain materials.

It should be noted that the first strategy, interfering with the vital activities of the organism, can be accomplished without recourse to chemical treatment. Modification of the environmental factors required for the growth of mold is at least as effective as chemical treatments, and certainly far safer for both personnel and materials.