This teaching guide covers the identification, deterioration, and conservation of artifacts made from plants It will be a valuable resource for conservators and students alike

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The Conservation of Artifacts Made from Plant Materials

Sulfuryl fluoride, sold commercially as a fumigant by Dow Chemical Company under its trademark Vikane, is currently being examined for use in museums and historic structures as a pest control agent. While little to no visible damage to materials is noted when Vikane is properly used, the selection criteria for a museum fumigant must be founded on an in-depth analysis of its possible effect on the physical and chemical properties of exposed artifacts. This article forms a basis for the evaluation of sulfuryl fluoride by providing a comprehensive review on Vikane, including information regarding the uses, chemical reactivity, physical properties, efficacy, and toxicity of sulfuryl fluoride.

Sulfuryl fluoride (vikane): a review of its use as a fumigant

The use of inert atmospheres (low oxygen) as an alternative to conventional fumigation techniques was investigated. Mixed cultures of several common museum pests including Tineola bisselliella, Lasioderma serricorne, Stegobium paniceum, Anthrenus vorax and Lyctus brunneus were purged with nitrogen gas for one, two and three weeks under controlled environmental conditions. One hundred percent mortality was observed in all cases though further quantitative tests are required to establish statistically valid mortality rates.

Inert atmosphere fumigation of museum objects

Laboratory cultures of a number of common museum pests including Tineola bisselliella (Hummel), Lasioderma serricorne (Fabricus), Stegobium paniceum (Linnaeus) and Anthrenus vorax (Linnaeus), were exposed to low oxygen atmospheres (0·4% oxygen, balance nitrogen) at 30°C for three weeks. Complete mortality was observed for all developmental stages. The possible application of low oxygen atmospheres as an alternative to conventional chemical fumigation techniques is discussed in terms of these experimental trials.

The effects of low oxygen atmospheres on museum pests

From the mid-18 th century onwards, pests, particularly insect pests, were viewed as the greatest threat to the preservation of collections. Initially, collectors combated pests through the use of metal salts, some aromatic herbs and oils, and possibly toxic derivatives from plants, such as strychnine. Collection growth, the use of cabinets to store specimens, and discoveries in organic chemistry eventually led to the use of gas-phase chemicals as fumigants for the contents of individual cabinets or for large-scale treatments. The legacy of pesticide use continues to pose problems for staff and various collections users, especially the recipients of repatriated objects. Modern pest control for collections focuses on prevention first, and then on treatments that do not leave lasting residues. Aside from pesticides, other potentially hazardous contaminants on collections include: residues from mold, rodent, or insect infestations; soot; asbestos from decrepitating building or pipe insulation; and powdered lead paint from old storage furniture. Efforts are underway to record the history of collections and their treatment, develop tests to identify and mitigate various contaminants, and to evaluate the risks from potentially hazardous residues. Modern practice places human safety above the safety of objects or specimens. In the long run, this approach, along with improvements in storage and display techniques should help ensure that collections will be preserved with less alteration in the future.

Historical survey of the sources of contamination of ethnographic materials in museum collections

The literature survey on the effects of ethylene oxide on artifact material shows explicitly that there are potential changes in materials of artifacts on fumigation with ethylene oxide, e.g. chemical solubility, pH, adsorptive ability, and strength characteristics, as well as introducing humectants and products of ethylene oxide. Ethylene oxide, and its product ethylene glycol, which may form in artifact materials, are hazardous to man. They are mutagenic, carcinogenic and toxic, and difficult to monitor. Freezing of artifacts under specific conditions, and using specific procedures has been recommended as an alternative. The literature survey on the effects of freezing on materials that would be found in artifacts shows that there are potential water hazards which can easily be prevented. Bound water in dry artifact material, and water in damp materials in capillaries less than 30u will not form ice crystals at -20°C. Condensation caused by reduced holding capacity of air or warm air cooling adjacent to cold objects can be prevented. Freezing should not be used for non-adsorptive materials. Physical and dimensional changes are minimal at the recommended -20°C. Essential procedures for freezing artifacts are listed. -- AATA

Mary-Lou Florian

Papers

The effect on artifact materials of the fumigant ethylene oxide and freezing used in insect control