The whole publication in PDF - Culture in Development

Ethylene oxide (ETO), a gaseous fumigant, was commonly used in libraries and archives until the 1980s; many
libraries had their own ETO chambers. ET O is effective against insect adults, larvae, and eggs. It poses serious
health hazards to workers, and there is evidence that ETO can change the physical and chemical properties of paper,
parchment, and leather. Governments have steadily lowered acceptable limits on ETO exposure, and most existing
ETO chambers in libraries cannot meet these restrictions. Some residual ETO remains in treated materials, and little
is known about the long-term risks to collections and staff from off-gassing toxins. ETO should be used only as a
last resort; materials should be sent to a com mercial facility and allowed to off-gas for several weeks at least before
being returned to the library or archives. In the Netherlands ETO is forbidden as a treatment for paper and related
products.
7.4.1.2. Methyl Bromide
Sometimes methyl bromide is used instead of ethylene oxide. Methyl bromide is sold under different names: Bromo-Gas,
Celfume, Embafume, MB, M eBr, Methogas, Profum e, Terr-o-G as, and Zytox. It is a colourless, volatile
liquid or gas with a chloroform-like odo ur. When used as a soil fumigant, only a small amount of methyl bromide
is transformed into the bromide ion while much o f the gas enters the atmosphere. Methyl bromide is moderately
toxic to aquatic organisms. In the Netherlands methyl bromide is banned as a soil disinfectant in greenhouses. In
its place hot steam is applied which is much better for the environment.
Even a little methyl bromide is highly toxic. Studies in humans indicate that the lung may be most severely
injured by the acute (short-term) inhalation of methyl bromide. Acute inhalation of methyl bromide frequently leads
to neurological effects in humans. Effects may be delayed.
Data suggest that mild functional neurological impairment may result in humans chronically (long-term) exposed
to methyl bromide by inhalation exposure.
7.4.1.3. Sulphuryl Fluoride
Vikane is the commercial name for the gas sulphuryl fluoride. The gas is in use to fumigate wood and timber
structures. It penetrates deeply into the woods and often thoroughly eliminates the pests. Depending on the
construction of the building, the doors and windows may be sealed with tape and a plastic sheet, or the structure may
be covered with a tarpoline. The building will remain sealed for 2-72 hours depending on the specifics of the job.
Warning signs should be posted around the building, notifying people to keep out. After the tap e is removed, a
professional fumigator will aerate the structure by opening the doors and windows. Fans may also be used to clear
out the building. O nce the edifice has been tho roughly aerated, the fumigator is required to measure the level of any
fumigant remaining in the living space to ensure it is below the approved concentration for re-entry by the occup ants.
The fumigator will post a notice on the building indicating the day and time for re-entry. Because Vikane is a true
gas and not a vapour, aeration is rapid. Recent studies demonstrated that in most structures levels are less than 1 part
per million within 6 hours of clearing and have no detectable levels of Vikane within 24 hours after the start of
aeration.
Research has been undertaken to assess the potential damage of Vikane to modern and traditional resins and
waxes pigments, as well as metals. The scientists investigated the potential interaction between Vikane and proteins
and dyes. Little to no visible damage to materials was noted when Vikane was properly applied. T he results indicate
that some possible harm could be inflicted to archival materials Additionally, it was determined that documentation
of fumigation should be recorded for each object so that future treatments take the fumigation history into ac count.
Sulphuryl fluoride (Vikane) is a colourless and odourless gas. It is therefore imperative to add a warning agent
to this gas. Sulphuryl fluoride is a po tential health hazard and enters the body through inhalation. Overexposure to
high levels of sulphuryl fluoride can result in nose and throat irritation and nausea. At high concentrations (such as
those used during fumigation) it can cause excess fluid in the lungs, sleepiness, pneumonia, and co nvulsions. These
symptoms would be expected to appear within 8 ho urs after such an exposure. In the unlikely event that staff
experience these symptoms in the building that has been recently fumigated, they should leave immediately. The
pest control company should retest the building. Because sulphuryl fluoride is a gas, it does not stay on dry surfaces,
thus there is no exposure when touching treated surfaces.
7.4.2 Non-ch emical Treatmen ts
A variety of non-chemical processes for exterminating insects have been explored. The most promising are
controlled freezing and the use of modified atmospheres. Methods that have not proved as successful include the
use of heat, gamma radiation, and microwaves.
7.4.2.1. Freezing, Freeze-drying And Other Cold T reatments
Controlled freezing has been applied in various institutions over the past 15 years. Reports on its effectiveness have
been largely favourable. Freezing is attractive because it involves no chemicals and thus poses no hazard to library
staff and the environment. It can be used on most library materials and does not appear to damage collections, but
research into this question is not yet complete. Very fragile objects, those made from a combination of materials,
and artefacts with friable media should probably not be frozen. Materials can be treated in household or commercial
freezers, blast freezers, or controlled-temperature and humidity freezers. It is necessary to bag and seal items unless
a freezer with specially controlled temperature and humidity is used. Bags must be sealed immediately to prevent
insects from escaping. Some institutions box materials and then bag them. Bagging protects objects from changes
in moisture content during defrost cycles and from condensation on cold books when they are removed from the
freezer. It is essential to guard against freeze resistance; som e insects can acclimate to co ld temperatures if they are
kept in a cool area before freezing or if freezing happens too slowly. Research is inco mplete in this area; it is not
known if common library pests are able to develop freeze resistance. In the absence of definitive data, material must
be kept at room temperature until freezing begins. Items should not be packed too tightly within a freezer, since this
can slow the freezing process. Most important, material should be frozen quickly. Freezer temperature should reach