INFOBOX:

Hadrobregmus pertinax is a species of woodboring beetle within the genus Hadrobregmus of the family Anobiidae. The adult is black, with yellow hairs at the back corners of its head, and is 4-5 mm long. The larva is white, about 5 mm long, and lives in decaying wood. The larval stage lasts many years.

The English name "Death watch beetle" name comes from the sound resembling the ticking of a clock, made by the male striking its head against the surface of the infested wood in order to attract a mate. It is the most destructive insect of buildings in England, Finland and in some parts of The Netherlands, Germany and Austria, where it survives the long winters in below-freezing temperatures. Because the larva lives in decaying wood, its presence indicates moisture damage. Resolution of the moisture problem will cause the beetle to leave. In many cases it is not possible to remove moisture.

INFOBOX: Gasreinigung

Handelsübliches Vikane-Gas enthält -obwohl 99,8%ig- immer noch herstellungsbedingt Säuren und Säureanhydride (=0,2%), wie HF, SOF₂, HCl, SO₂Cl₂, Cl₂ etc. Diese können z.B. Glas oder Metalloberflächen durch Korrosion schädigen. Deshalb wurde von Binker Materialschutz GmbH ein Reinigungsverfahren entwickelt, bei dem all diese Verunreinigungen vor der Anwendung des Begasungsmittels herausgefiltert werden, so dass nur hochreines und damit nicht-korrosives Sulfuryldifluorid in die Museumsgebäude eingeleitet wird bzw. nur "sauberes" Vikane auf die Schädlinge in den zu begasenden Museumsobjekten einwirkt. Würden z.B. 250 kg ungereinigtes Vikane in ein Museum eingeleitet, kämen zusätzlich 0,5 kg (=ein halbes Kilo!) Säuren/Säureanhydride ins Museum! Schäden wären so vorprogrammiert.

INFOBOX: Tarping for fumigation

Woodborers (like House longhorn beetle and Anobiids) pose a potential threat to the wooden interior of museum. They infest the wood beams of the roof construction and the wooden interior as well. The favourite measure to get rid off the pests is a fumigation with the fumigant Sulfuryl fluoride (Trademark Vikane). Sulfuryl Fluoride is a colorless and odorless gas. It is non-staining, non-corrosive, and non-flammable. It does not deplete the ozone layer. Sulfuryl fluoride is highly toxic to all post-embryonic life stages of insects. Eggs of most species are less susceptible but can be killed as well applying higher dosages. Sulfuryl fluoride has been demonstrated to reduce oxygen uptake in insect eggs. The efficacy of sulfuryl fluoride depends on the concentration reaching the target pest and the duration of exposure. Our fumigators use a calculation system called the "Fumiguide " to determine the amount of Vikane required for specific pest and fumigation conditions (taylored fumigation or precision fumigation). The required dosages of Vikane are mainly influenced by the temperature at the site of the pest, the length of the exposure period, containment or the rate the fumigant is lost from the structure, and very important the susceptibility of the pest to be controlled. Sulfuryl fluoride prevents insects from metabolizing the stored fats they need to maintain a sufficient source of energy for survival by disrupting the glycolysis cycle. Fumigation is the only method of insect pest control that is able to kill a target insect regardless of its location within the museum structure. Unlike other treatment methods used, fumigation allows the gas to penetrate every possible point of the museum structure where a target Anobiid insect may be located as the most common here in Europe, like in Germany, Austria, Italy, Spain etc. Other common target pest for fumigations are Powder Post Beetles (Lyctidae), Old House Borer Beetles (hylotrupes bajulus), Golden Spider Beetle (Niptus hololeucus) and the Hump Spider Beetle (Gibbium psylloides). Technical fumigant Vikane contains still some corrosive impurities like acids and acid anhydrides from the production process. Vikane is produced from an anhydrous gaseous mixture of sulfur dioxide, chlorine, and hydrofluoric acid in the presence of a charcoal catalyst heated to 35°C according equation (1):

This chemical process results in a fumigant with a purity of greater than 99.8%. The impurities are composed of residual starting materials and byproducts in concentrations of at least 2000 ppm in the liquid Vikane. While the concentrations of these low-level impurities (HF, HCl, Cl₂, SO₂, SOF₂ and ethylene dichloride) may not be high enough after dispersal to cause observable changes to materials, their presence is important since most of them are highly reactive. Conservators must also be concerned with the possibility of cumulative fumigation effects, since museum collections are stored over long periods and may be fumigated repeatedly. Thus, as a precaution, the acidic impurities (HF, HCl, Cl₂, SO₂, SOF₂) may be removed by passing the gaseous Vikane through a filter system called "Altarion Viklean"-Filter. This procedure was patented by Binker Materialschutz GmbH to prevent metals, sensitive materials and artefacts from negative altering. We call the purified Vikane fumigant "Altarion® Vikane®". Museum structures with leaky wooden walls and ceilings have to be totally tarped to achieve a proper sealing of the entire building for the fumigation otherwise the fumigant will be lost from the fumigation space into the ambient air. This would make the fumigation ineffective.

Example of a tarp job: museum structure fumigated near city of Salzburg/Austria

There are five steps to a museum tarp fumigation:

• Sealing the Structure: covering the entire structure with tarps to create an airtight bubble.
• Pressure testing to check for gas leaks and to estimate the half loss time of gas loss.
• Altarion Vikane® (Sulfuryl Fluoride) Release: a specifically calculated amount of the fumigant Vikane is released into the museum building based on volume calculation, weather conditions (wind) as well as the target pest and life stages present. Technical Vikane is released from cylinders passing it through the Altarion® Viklean®-filtering system.
• Fumigant Exposure: length of time the target pests are exposed to the fumigant based on calculations for the structure. This period is usually between 60 and 120 hours.
• Aeration: tarps are removed to allow the Sulfuryl Fluoride to escape from the fumigated structure. This process is aided with the use of exhaust fans and ductwork to avoid non-target exposure.
• Clearance: Once the fumigation is complete, our fumigators will conduct the aeration procedure. Clearance involves checking the air within the structure with a highly sensitive clearing device for any remaining fumigant. Only after the structure has been certified clear will persons be allowed to re-enter the structure.

INFOBOX:

Testblöcke: Zur Überprüfung der Wirksamkeit von Begasungen werden Testinsekten (Anobien- oder Hausbocklarven) in hölzernen Testblöcken vor der Begasung in die zu begasenden Museumsgebäude eingelegt und in unterschiedlichen Raumhöhen postiert.

Die Testblöcke werden nach der Begasung aus den belüfteten und Begasungsmittel-freien Gebäuden entnommen und im Labor ausgewertet. Die vollständige Abtötung aller Test-Larven bestätigt dem Auftraggeber gegenüber die volle Wirksamkeit der Begasung.