Using the Thermo lignum Using the Thermo lignum heat process for treatment heat process for treatment

of natural history specimensof natural history specimens--

Research and practical Research and practical experienceexperience

David PinnigerDavid Pinniger

Integrated pest management is Integrated pest management is essential to prevent insect damage essential to prevent insect damage

to collectionsto collections

Main components of IPMMain components of IPM

Checking for pestsChecking for pests

Good housekepingGood housekeping

Good environment without extremes Good environment without extremes of temperature or humidityof temperature or humidity

Quarantine procedures to prevent Quarantine procedures to prevent introduction of live pestsintroduction of live pests

Safe and effective control treatments Safe and effective control treatments for objectsfor objects

Options for control treatmentsOptions for control treatments

Low temperatureLow temperature

AnoxiaAnoxia

Carbon dioxideCarbon dioxide

High temperatureHigh temperature

Low temperatureLow temperature

-20°C for 2 -20°C for 2 weeksweeks

-3o°C for 3-5 -3o°C for 3-5 daysdays

Effective but Effective but objects MUST objects MUST be bagged to be bagged to prevent prevent moisture moisture changeschanges

Carbon dioxideCarbon dioxide

Effective, but Effective, but exposure can exposure can take 3 weeks take 3 weeks or moreor more

Issues with Issues with registration in registration in some some countriescountries

AnoxiaAnoxia Can be effective, Can be effective,

but exposure but exposure can take 3 – 5 can take 3 – 5 weeks weeks

Difficult to Difficult to maintain 0.3% maintain 0.3% oxygen for a oxygen for a long periodlong period

Not effective for Not effective for some wood some wood borersborers

Heat treatmentHeat treatment

Historical use of heat to kill Historical use of heat to kill insectsinsects

Heating food on sheets in Heating food on sheets in tropics tropics

Heating buildings to kill food Heating buildings to kill food pestspests

Heating insect drawers to kill Heating insect drawers to kill carpet beetlescarpet beetles

How high a temperature do you How high a temperature do you need to kill insects?need to kill insects?

5252°°C for most museum pestsC for most museum pests

5555°° C g for some woodborers C g for some woodborers such as such as HylotrupesHylotrupes

1 to 2 hours exposure will kill 1 to 2 hours exposure will kill

insect eggs, larvae, pupae and insect eggs, larvae, pupae and adultsadults

The main issues using heat with The main issues using heat with uncontrolled humidityuncontrolled humidity

Drying out of objectsDrying out of objects Splitting, shrinkage and crackingSplitting, shrinkage and cracking

What happens if you control the What happens if you control the humidity to a set level?humidity to a set level?

There is no There is no transfer of transfer of moisture from moisture from the object to the the object to the environmentenvironment

No shrinkage, No shrinkage, cracking or cracking or distortiondistortion

Development of the Development of the ThermoLignum ChamberThermoLignum Chamber

Computer controlled heat/ Computer controlled heat/ chamber with RH control chamber with RH control developed in Germanydeveloped in Germany

UK chamber in operation since UK chamber in operation since 19941994

Chambers also in Austria, Norway Chambers also in Austria, Norway Switzerland and BelgiumSwitzerland and Belgium

Operating systemOperating system

The key is to introduce moisture in the The key is to introduce moisture in the heating cycleheating cycle

Remove moisture in the cooling cycleRemove moisture in the cooling cycle

Practical treatmentsPractical treatmentsObjects treated for major UK museums Objects treated for major UK museums

include:-include:-

BooksBooks ArchivesArchives TextilesTextiles LeatherLeather UpholsteryUpholstery Wooden objectsWooden objects Contemporary ArtContemporary Art

Trials at the Natural History Trials at the Natural History Museum LondonMuseum London

MammalsMammals BirdsBirds CrustaceaCrustacea InsectsInsects Vascular plantsVascular plants BryophytesBryophytes LichensLichens FishFish

Further trials to measure relative Further trials to measure relative humidity inside insect drawershumidity inside insect drawers

Generally very stable and consistent Generally very stable and consistent conditions in closed insect drawersconditions in closed insect drawers

Key issuesKey issues

Spacing of drawers Spacing of drawers to ensure sufficient to ensure sufficient air circulation spaceair circulation space

[See Ackery [See Ackery et alet al 2005 for details] 2005 for details]

What is the effect of heat What is the effect of heat treatment on DNA?treatment on DNA?

Some concerns that 52Some concerns that 52°C°C may affect may affect subsequent DNA extraction from subsequent DNA extraction from specimensspecimens

Trials of fresh and aged insect Trials of fresh and aged insect material at the NHM London showed material at the NHM London showed no effect on DNA extractionno effect on DNA extraction

[See Ackery [See Ackery et alet al 2004 for details] 2004 for details]

Other researchOther research

Kigawa et alKigawa et al 20032003

Tested the effects of a range of Tested the effects of a range of treatments on DNA of fungi and treatments on DNA of fungi and chicken meatchicken meat

Heat, freezing and anoxic treatments Heat, freezing and anoxic treatments had no measurable effects on DNAhad no measurable effects on DNA

Practical treatments of natural Practical treatments of natural history collections in the UKhistory collections in the UK

Scarborough, EnglandScarborough, England

Practical treatments of natural Practical treatments of natural history collections in the UKhistory collections in the UK

Kew HerbariumKew Herbarium

Key benefits in practiceKey benefits in practice

Speed of treatment - 24 hour cycleSpeed of treatment - 24 hour cycle

No need to bag objects – particularly No need to bag objects – particularly costly with large scale freezing costly with large scale freezing programmesprogrammes

Energy consumption - Need for Energy consumption - Need for detailed cost breakdown of -30C for 3-4 detailed cost breakdown of -30C for 3-4 days and +52C for a few hoursdays and +52C for a few hours

Heat treatments in the future?Heat treatments in the future?

Ensure that there is clear understanding of Ensure that there is clear understanding of

the difference between heat treatments with the difference between heat treatments with and without controlled humidity and without controlled humidity

Demonstrate the low risks to collections Demonstrate the low risks to collections from controlled humidity heat treatmentsfrom controlled humidity heat treatments

Wider acceptance in the light of advantages Wider acceptance in the light of advantages of labour input and energy budgetof labour input and energy budget