researc The Getty Conservation Institute h in Inert Gases in the Control of Museum conservation Insect Pests Charles Selwitz Shin Maekawa Inert Gases in the Control of Museum Insect Pests research The Getty Conservation Institute Inert Gases in the in Control of Museum Insect Pests conservation Charles Selwitz Shin Maekawa 1998 Tevvy Ball, Managing Editor Elizabeth Maggio, Copy Editor Amita Molloy, Production Coordinator Garland Kirkpatrick, Series Designer © 1998 The J. Paul Getty Trust All rights reserved. Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 Library of Congress Cataloging-in-Publication Data Selwitz, Charles, 1927- Inert gases in the control of museum insect pests / Charles Selwitz, Shin Maekawa. p. cm. — (Research in conservation) Includes bibliographical references (p. ) and index. ISBN 0-89236-502-1 (pbk.) 1. Museum conservation methods—Research. 2. Museum exhibits— Conservation and restoration. 3. Insect pests—Control—Research. 4. Gases, Rare. 5. Nitrogen. 6. Oxygen. 7. Carbon dioxide. 8. Anoxemia. I. Maekawa, Shin, 1952- . II. Getty Conservation Institute. III. Title. IV. Series. AM145.S45 1998 069’.53—DC21 98-7310 CIP The Getty Conservation Institute works internationally to further the apprecia- The Getty tion and preservation of the world's cultural heritage for the enrichment and use of present and future generations. The Institute is an operating program of the Conservation J. Paul Getty Trust. Institute The Research in Conservation reference series presents the findings of research Research in conducted by the Getty Conservation Institute and its individual and insti- tutional research partners, as well as state-of-the-art reviews of conservation Conservation literature. Each volume covers a topic of current interest to conservators and conservation scientists. Other volumes in the Research in Conservation series include Oxygen-Free Museum Cases (Maekawa 1998); Stone Conservation: An Overview of Current Research (Price 1996); Accelerated Aging: Photo- chemical and Thermal Aspects (Feller 1994); Airborne Particles in Museums (Nazaroff, Ligocki, et al. 1993); Epoxy Resins in Stone Consolidation (Selwitz 1992); Evaluation of Cellulose Ethers for Conservation (Feller and Wilt 1990); Cellulose Nitrate in Conservation (Selwitz 1988); and Statistical Analysis in Art Conservation Research (Reedy and Reedy 1988). ix Foreword Contents Miguel Angel Corzo xi Preface xv Acknowledgments 1 Chapter 1 Mechanisms of Insect Mortality Desiccation Anoxia at High Humidities 7 Chapter 2 Anoxia as a Conservation Procedure From Food Preservation to Conservation Early Museum Anoxia Studies Determining Kill Times Thermal Techniques Killing Burrowed Insects 17 Chapter 3 Methods and Materials Barrier Films Gas Supplies Oxygen Scavengers Closures Heat Sealers Zippers Clamps Adhesive Strips Portals 29 Chapter 4 Operational Problems and Practices Humidification Argon versus Nitrogen Monitors Electronic Oxygen Monitors Passive Oxygen Monitors Carbon Dioxide Monitors Relative Humidity Monitors Temperature Sensors Leak Detectors Monitoring Life Signs Safe Use of Nontoxic Fumigants 41 Chapter 5 Anoxia Treatment in Barrier-Film Bags General Procedures Conservators' Experience Comments 49 Chapter 6 Anoxia Treatment in a Dynamic Mode Treatment in Small Pouches Treatment in Constructed Containments Objects at the J. Paul Getty Museum Back Seat Dodge '38 The Spanish Piano vii 57 Chapter 7 Reusable Anoxia Systems Flexible Chambers The Getty Barrier-Film Tent The Small Rentokil Bubble The Large Rentokil Bubble Rigid Chambers Homemade Containers Vacufume Chambers 67 Chapter 8 Fumigation with Carbon Dioxide Effectiveness of Carbon Dioxide versus Nitrogen Carbon Dioxide Fumigation Requirements Treatment Experience in the United States Old Sturbridge Village The Winterthur Museum Society for the Preservation of New England Antiquities The Oakland Museum The Smithsonian Institution Treatment Experience in Canada The National Museum of Science and Technology The Canadian Museum of Civilization Treatment Experience in Germany 79 Appendix A: Professional Contacts 81 Appendix B: Materials and Suppliers 91 Appendix C: Common and Scientific Names of Insect Species 93 References 101 Index 107 About the Authors viii The interest of the Getty Conservation Institute in the management of pest Foreword control reached a turning point in 1987 when Nieves Valentín, then with the Instituto de Conservación y Restauración de Bienes Culturales (now called the Instituto del Patrimonio Histórico Español) in Madrid, Spain, came to the GCI for a tenure as a Fellow to continue her conservation research on ways to stop bio- logical attack on organic materials. Concerned about the impact that traditional pesticides have on both conservators' safety and the environment, the Institute recognized the need to contribute to the development of newer, safer tech- niques for halting the damage done by insects, fungi, and algae to museum col- lections. With this goal in mind, the GCI invited Dr. Valentín to join its staff and pursue her research in this important area of conservation. Her presence at the Institute and the enthusiasm she generated in her field of endeavor opened further avenues of exploration. Since then, the GCI has continued research in this field both in-house and with associated institutions. This has resulted in a number of completed projects such as storage cases for the Royal Mummies of Egypt's National Museum; display cases to protect the Constitution of India developed in collaboration with the National Physical Laboratories of that country; cases for mummies in the Museo Balaguer in Barcelona, Spain; the disinfestation of Kienholz's Back Seat Dodge '38, done in collaboration with the J. Paul Getty Museum and the Los Angeles County Museum of Art; the display case for the Hudson Bay Charter, in Toronto; and technical advice for the conservation of the Declaration of Arbroath in Scotland. Additionally, the Institute has offered pest control management courses in various locations around the world. Inert Cases in the Control of Museum Insect Pests is a compendium of informa- tion on the biological mechanisms by which nontoxic gases kill insects; the methods and materials needed to create and maintain an anoxic atmosphere; treatments; the construction and use of chambers and bubbles; and the proce- dures for treating objects. This publication is a continuation of the Institute's Research in Conservation series, which aims to make available the findings of research conducted by the Institute and its partners as well as provide state-of-the-art reviews of conserva- tion literature. From its inception the Institute has sought to open to the conser- vation professions the results of its research and experience in areas that bridge the gap between contemporary science and technology and current conserva- tion practice. In addition to Nieves Valentín, GCI senior scientist Shin Maekawa and GCI Fellows Kerstin Elert and Vinod Daniel have dedicated much of their time to this area, and a number of other institutions also have collaborated in our research efforts. With his usual scientific rigor, organizational skills, and attention to detail, Charles Selwitz undertook the exacting task of reviewing the literature and the research done at the Institute and by other individuals and organizations to pro- duce this publication. To him, to my colleagues, and to our partners, I extend my sincere acknowledgment. I hope our readers will find in these pages the information and expertise that will provide them with further means to continue in our joint efforts to help conserve the world's cultural heritage. —Miguel Angel Corzo Director The Getty Conservation Institute ix x Over the centuries, one of the most persistent causes of loss of cultural property Preface and museum collections has been damage done by insects. Prime targets are manuscripts on paper and parchment, natural history collections, and herbaria, but massive wooden objects also are often attacked and, occasionally, seriously harmed. Throughout the nineteenth and most of the twentieth centuries, the response to this biological assault has been to use an array of highly toxic chemi- cals, an approach that has resulted in many well-documented negative conse- quences. More recently, the conservation community has begun to appreciate that prevention is a better approach and that there are physical and biochemical procedures that can safely substitute for pesticides when prevention is occasion- ally inadequate. As embodied in a program of regular inspections, good house- keeping, and maintenance, prevention is designed to avoid providing pests with access to collections and is more commonly called integrated pest man- agement. Better and safer killing methods to treat an established infestation include the use of biologically active agents such as pyrethrums and juvenile growth hormones, and physical means such as desiccation with nontoxic gases, freezing, and heating. Increasingly, well-established pest control programs at both small and large institutions are being built on the considered use of all of these options. This book is about one option, the use of nontoxic gases (argon, nitrogen, and carbon dioxide) to rid museum objects of insect pests. Conservators are selecting this approach because they feel more comfortable and confident that using inert gases is much less likely to harm objects than other procedures. Curators have been known to insist that disinfestation be carried out by anoxia (which