Reprinted with permission from CAN #14, July 1983. The reporter is Mildred O'Connell, Field Service Director, NEDCC.
The two-day seminar, "Pest Control: Protecting Cultural Properties,' attracted approximately sixty conservators, curators, administrators and insect-control experts on April 22 and 23, 1983, Held at the Massachusetts Institute of Technology, the seminar was co-sponsored by Technology and Conservation Magazine and the MIT Museum. Topics included identification of insects, extermination treatments and control measures, with specific attention given to questions of human health and safety and the effect of fumigants on collection materials.
Linda Mark, President of Fine Objects Conservation, Cambridge, Massachusetts, opened the seminar with a discussion of environmental conditions which determine insect activity. She also noted that curators should always consult with a conservator before using chemicals on objects, citing the example that aerosol mist pesticides contain an oil base which can be harmful to certain objects.
Gary Alpert, Entomologist at Harvard University, stressed the need to collect and identify insects before beginning a pest eradication program. Identification often enables curators to trace and eliminate the origin of infestation, thus preventing a recurrence. Removal of the source of infestation is more effective than fumigation of individual objects. Dr. Alpert also described trapping methods and recommended that traps and not rodenticides be used for mice and rats, since dead mice inside wall boards can become reservoirs for insects.
Harold Day of the U.S. Environmental Protection Agency emphasized the importance of following label directions on pesticides. He also cautioned participants against the temptation to manufacture pesticides themselves when favorite products are withdrawn from the market because they are considered to be dangerous.
Doris Freitag, Book Conservator at Harvard University, shared her experiences of installing and operating an ethylene oxide vacuum fumigation chamber. Participants were able to visit her facility, as well as Harvard's Entomology Laboratory.
A review of the literature on safety of fumigant a for collection materials was offered by Mary-Lou Florian, Conservation Analyst at the British Columbia Provincial Museum.
Judy Siggins, Assistant Director at Dumbarton Oaks, graphically described her institution's battle against black carpet beetles, which culminated in the fumigation of the entire collection. Collections were treated with ethylene oxide inside tractor trailer trucks which were converted into atmospheric fumigation chambers. The building was treated by crack-and-crevice spraying, area by area, while the collections were gone. Continued efforts to control infestation include biannual spraying and frequent inspection of building and collections. Pheromone traps and fine mesh screening are also used.
Precautions and procedures for fumigation treatments were ably described by Richard Berman, Technical Manager of the Waltham Chemical Company in Waltham, Massachusetts. He advised that an attempt be made to use the least amount of pesticide and the least toxic pesticide possible. He noted that fumigation is dangerous and not always applicable, and stressed that it should be avoided altogether if it cannot be done safely, or if there are other ways to treat the problem. If fumigation is deemed necessary, then various methods can be used, including stack fumigation, vehicle fumigation (as at Dumbarton Oaks), building fumigation, or fumigation inside a chamber (atmospheric or vacuum).
Mr. Berman described chamber fumigation as being the easiest, most convenient, and best quality method. However, he stressed safety hazards of vacuum chambers and the need for proper maintenance. He explained that operators of vacuum fumigation chambers often require certification by local governments. He also noted that efficacy of vacuum fumigation depends on temperature (optimum is 70-95°F), on quality of seal, amount of gas used, hold time, humidity and circulation of air. He stressed the need for having one person in charge of safety, who is trained and certified; he also advocated the use of gas monitoring devices, and urged operators to notify local fire and security agencies, as well as staff, of the hazards of the chamber.
William Lull, Conceptual Systems Consultant for Syska & Hennessy, Inc., stated that curators must have collections storage facilities designed to suit their needs. He emphasized that they need to control the engineers and architects who design new collections storage facilities.
Joan Lester, Curator of Collections at Boston's Children's Museum, presented a case study of an attempt to control insects during their recent move of collections to a new building. Moving trucks were filled with collections objects and moved to a warehouse where the contents were fumigated inside the trucks. Ficam dust was used to treat the new (sealed) storage area.
Richard Mathews, Sales and Marketing Manager, Vacudyne Altair, described recent testing involving operator exposure to ethylene oxide. Recommendations resulting from these tests include: 1) limiting operator exposure; 2) ventilating the chamber overnight, if possible, but at least while the chamber is being loaded and unloaded; 3) ventilating the area where the fumigator is located; and 4) ventilating the area where articles are kept after fumigation.
John Dawson, Conservation Scientist at the Canadian Conservation Institute, stated that ethylene oxide is safe to use on a wide range of materials. He recommended that fumigation chambers be purged three or four times before opening in order to reduce health hazards and that fumigated materials be allowed to air for three days before they are handled.
This discussion took place at the AIC meeting in a special general session and was moderated by Barbara Appelbaum. Linda Mark reported on the Cambridge conference in April; Michael McCann summarized results of a recent survey of fumigation practices in New York Museums, commented on most frequently used fumigants, and spoke on precautions and alternatives; Mary-Lou Florian described the adverse effects of fumigants on objects and said that her museum has stopped using ethylene oxide. Richard D. Smith and others contributed to the discussion period afterward. Some of the more interesting points that are not covered elsewhere in this Supplement are given below.
McCann: The proposed OSHA standard for EtO is 1 ppm [down from the SO ppm reported as current in AN, July '82], with an "action level" of 1/2 ppm at which signs must be posted and medical surveillance gotten; but none of the monitoring equipment now in use can detect EtO at that level. Salt combines with EtO to yield ethylene chlorohydrin, which is about as toxic as EtO but is worse in a way because it is not volatile, is rapidly absorbed, and causes no sensation. [A later speaker said it couldn't be monitored.] Fortunately, it can be washed off with water.
He summarized the effect of about 10 other fumigants or repellants, including thymol and OPP. The main thing you need with thymol is a flushing mechanism, which can be cheap: a dryer hose is fine, and can be easily replaced if affected by the vapor. Some people are substituting the less toxic OPP, and using it in a chamber.
Some alternatives to use of toxic, broad-spectrum fumigants are: environmental control; sealing off cracks and openings (except doors, of course) between rooms to prevent spread of infestations; identifying the species first, before doing anything (this is a step that will become increasingly important as biological controls are used more widely; and inspecting incoming materials and doing spot fumigation.
Florian: She searched the literature for effects of various fumigants and residues on materials, and found many effects that were significant and irreversible. She advocates the use of non-chemical alternatives except as needed for emergency infestations and for specific incoming materials identified as requiring fumigation. More non-chemical alternatives need to be found. The changes she found reported in the literature involved pigments, strength of degraded textiles and other materials, adhesion, surface of bindings (some became sticky), and characteristics of proteinaceous materials (EtO changes their isoelectric point and electrophoretic characteristics, and crosslinks collagen).
Smith (speaking from the floor): Some non-chemical alternatives for killing insects are: heating the material to 140°F (which lowers humidity below a point that they can live in); lowering the temperature rapidly, before insects have a chance to manufacture their natural antifreeze, glycol (-10°F for 24 hours gets them all); and use of a vacuum table to lower the oxygen level, and if necessary replacing the air once with nitrogen or carbon dioxide.
In the discussion that followed, various speakers contributed the following remarks: Although fumigation may change the chemical characteristics of an object, fumigation records may not go into the treatment file for the object. Microwaves have been used for eradication of insects from textiles, and they did kill insects in 2-3 minutes, but the side effects were unacceptable: adhesives lost adhesion, pine cones caught fire, etc. Gamma rays are used in Russia, but are said to break chemical bonds and may soften leather. Vapona strips corrode metals, soften or dissolve resins, and turn aluminum foil to powder.
The session was recorded and is available on two cassettes from Cassette Recording, Inc., Attn: Richard Todd, 399 Arcade Square, P0 Box 1288, Dayton, OH 45402. Cost: $12 for the set of two, + $1 postage.
This report, by Perri Pelts, is reprinted with permission from Art Hazards News, June 1983.
On June 14-15, the Center for Occupational Hazards held a workshop on Safe Pest Control Procedures for Museum Collections at the Cooper-Hewitt Museum in New York City. This two-day workshop was co-sponsored by the New York State Conservation Consultancy and was funded in part by the New York State Council on the Arts.
There were a total of sixteen speakers at the conference who covered a wide variety of topics relating to all areas of pest control. The following topics were included in the workshop: the different classes of pesticides, the effects of fumigants on collection objects, the health effects of fumigants, fumigation procedures, respiratory protection and ventilation, and the legal questions that concern museums using pesticides and fumigants. Some of the speakers included: Richard Beauchamp, Chief Conservator, British Columbia Provincial Museum; Steven Markowitz, M.D., Montefiore Hospital; Michael McCann, Ph.D., C.I.H., Center for Occupational Hazards; Randall Dupree, Assistant Commissioner for Environment, New York City Health Department; and Robert B. Marcus, attorney, Wallman & Wechsler. [The program listed 15 speakers: 6 health professionals with organizations or government agencies; 3 conservators; 2 representatives of large chemical companies; 1 president of an exterminating company; 1 entomologist; 1 physician; and 1 attorney.:
Although many of the participants were conservators from museums in the New York City region, there were a considerable number of representatives from institutions in other parts of the country and Canada as well. Museums that were represented at the conference included the Metropolitan Museum of Art, the American Museum of Natural History, the Brooklyn Museum, Fashion Institute of Technology, the Philadelphia Museum of Art, the Smithsonian Institution, the Cincinnati Art Museum and the Royal Ontario Museum.
The workshop proceedings were recorded. The complete recordings of the conference are available in cassette from COH for $45.00 (8 cassettes C-90). Add $2.00 for postage and handling. The information packet distributed to conference attendees is also available from CON for $10.00. This includes an 8-page data sheet summarizing the conference. This data sheet is available separately for $1.50.