1.4 Potential Adverse Effects of Pest Control Agents on the Materials of Museum Artifacts

Canadian Conservation Institute

Helen Burgess
Nancy Binnie
Period of Activity: 6/86 to 6/89

Project Abstract
This study investigated the potentially harmful interaction between Vikane (sulfuryl fluoride) and cellulose, starch and lignin-containing materials. Changes in percent reflectance are reported after accelerated aging at 70 C and 50% relative humidity. Results were also obtained for average degree of polymerization, nitrophenylhydrazone carbonyl content, total acidity (by iodometry), extracted and surface pH, and tensile strength (Instron). The set of exposed samples numbered 25 groups of paper and textile fibers containing cellulosic and ligneous fibers.

Major Findings
The analysis of exposed papers has been finished. For paper then, the following interpretation of the data holds. Fumigation with normal grade Vikane causes an immediate large decrease in the alkaline reserve of buffered papers and a significant increase in acid in fibers which have an initial pH in the slightly alkaline to slightly acid pH range. Papers containing lignin show a development in acid functional groups in the following order: "old" ligneous papers >> "new" newsprint newsprint; > moderately aged, circa 1930. Age and fiber content also influence the results for the rest of the papers. The DP data go along with changes in the level of oxidation and increased acidity, namely that four of the eight fibers analyzed show that Vikane is causing a very large, significant drop in the average polymer length, which is detectable only after accelerated aging. The papers that did not change were either buffered or their DPwas already so low that further degradation is progressing at too slow a rate to be detectable. The implication here is that acid-catalyzed depolymerization is an important mechanism of the deterioration of paper fiber by Vikane. Fluoride levels are also elevated above background (control samples) especially for buffered papers and those with gelatine sizing but the causes for these values are somewhat uncertain. Results for XRM-5162 Vikane (with acidic impurities removed) have not been determined.

Primary Publications
Derrick, M. R., H. D. Burgess, M. T. Baker, and N. E. Binnie, "Sulfuryl Fluoride (Vikane®): A Review of Its Use as a Fumigant," Journal of the American Institute for Conservation,Vol. 29, 1990, pp. 77-90.

ABSTRACT-See same listing under project 1.3.

Burgess, H. D., and N. E. Binnie, "The Development of a Research Approach to the Scientific Study of Cellulosics and Ligneous Materials," Journal of the American Institute for Conservation, Vol. 29, 1990, pp. 133-152.

ABSTRACT-The evaluation of scientific results and recommendations in the conservation literature is greatly aided by a good understanding of the rationale behind the selection of test materials and methods. Unfortunately, space rarely permits the authors to fully explain such important issues as how the chemistry of the system under study has influenced their approach to the selection of analytical methods; the extent to which these experimental procedures can be expected to yield the desired information; and how closely the scientific model approximates the "real life" situations that the conservator meets in his or her laboratory. The authors have taken this opportunity to present their design considerations because the Vikane® project is one of the most complex and broadly based projects ever carried out in the field of paper and textiles by the Canadian Conservation Institute, involving some twenty-five separate fiber types ranging from modern to circa 1622, and nine different analytical procedures.

Druzik, J. R., H. D. Burgess, M. T. Baker, and M. R. Derrick, "Laboratory Investigation of the Fumigant Vikane®," American Chemical Society, Division of Environmental Chemistry, Miami, Florida, September 10-15, 1989.

ABSTRACT-See same listing under project 1.3.

Burgess, H. D., and N. E. Binnie, "The Effect of Vikane® on the Stability of Cellulosic and Ligneous Materials-Measurement of Deterioration by Chemical and Physical Methods," Materials Issues in Art and Archaeology II, Vol. 185, 1991, Proceedings of the Materials Research Society, Spring Meeting, San Francisco, California, April 16-20, 1990.

ABSTRACT-Vikane (sulfuryl fluoride) is a commercial fumigant which is used for the control of pests in museum collections. This paper summarizes the results obtained through an investigation of the effect of Vikane on 25 paper and textile samples. Samples chosen were representative of artifacts present in North American collections; (cotton, linen, jute, and wood pulp fibers, from 1622 to present). The effect of the fumigation treatment has been evaluated by chemical and physical analyses: (1) Acidity-surface pH, cold extraction pH, total acid (iodometric titration), (2) Oxidative and Hydrolytic Degradation-viscometric average degree of polymerization, carbonyl content (hydrazone derivitization) and (3) Fumigant Residues (specific ion electrode) Analysis of unfumigated and fumigated samples was carried out before and after accelerated aging(70 C and 50% relative humidity) in order to estimate the long-term stability of fumigated samples.

The data obtained show that commercial grade Vikane® degrades cellulose and ligneous fibers. A second set of experiments on two fiber types using an experimental grade of Vikane® (XRM-5162); gave significantly less degradation. The presentation of this work concentrates on a general scientific interpretation of the results. It is anticipated that the conclusions will be applicable to a broad range of artifacts.

Baker, M. T., H. D. Burgess, N. E. Binnie, M. R. Derrick, and J. R. Druzik, "Investigation of the Fumigant Vikane® " Preprints, ICOM 9th Triennial Meeting, Vol. 2, Dresden, August 26-31, 1990, pp. 804-811.