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Heat Treatment Considerations

Before – AfterOle Dosland

Director of Technical Training& E-Learning

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History of Heat

Early 1900’sGaining Popularity

Considerations Evolving

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Temperature Insect Response

ZoneLethal

Sub-optimum

OptimumSub-optimum

Lethal

Temperature120°F to 140°F110°F to 115°F95°F to 100°F75°F to 90°F65°F to 70°F55°F to 60°F35°F to 45°F-5°F to 10°F

-20°F to -10°F

Insect ResponseDeath in minutes

Death in hours

Development stops

Maximum development

Development slows

Development stops

Death in weeks

Most S.P.I’s die

Death in minutes,

insects freeze

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Heat Treatment

120°F. to 140°F. Target ZoneLower Humidity Likely

– As temperature increases, humidity decreases.

Lethal Target Zone for Insects

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Heat Sterilization

160°F +++++Quicker Insect KillMicrobial ReductionHarder on Equipment &

Structures

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Heat Treatment Duration

When temperature reaches 125°F. + for 2 hours, the mission has been accomplished.– Ambient, internal or external ???

»Wherever the insect is at.Wherever the insect is at.

Typical structuralstructural heat treatment duration– Set up & heat up (8 – 12 hours)– Hold temperature (24 – 36 hours)– Cool down (< 8 – 12 hours)

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Heat Treatment Duration

When temperature reaches 125°F. + for 2 hours, the mission has been accomplished.– Ambient, internal or external ???

»Wherever the insect is at.Wherever the insect is at.

Typical equipmentequipment heat treatment duration– Set up & heat up (4 - 6 hours)– Hold temperature (8 - 16 hours)– Cool down (< 4 - 6 hours)

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Heat Treatment Duration

When temperature reaches 125°F. + for 2 hours, the mission has been accomplished.– Wherever the insect is at.Wherever the insect is at.– Time is not as important as the

temperature.

Inside the walls Inside the equipment Inside the bins

Know your temperatures.

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Heat Treatment Considerations

Before

Planning Team–determine “what” to heat with “what”, and “when” monitored by “who”

–start a couple of months prior to a heat up– identify concerns for investigation & action

»check with suppliersget answers, make sure, do small tests

conduct progress meetings

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Equipment considerations–sprinkler heads, fire protection system

–mercury vapor lights–sensitive electrical

»computers–belt drives– lubricants–wood sifters

Heat Treatment Considerations

Before

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Removal of certain items–aerosol cans /pressured cylinders–fire extinguishers–sensitive ingredients, vitamins–packaging materials–sensitive electronics

Heat Treatment Considerations

Before

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Remove most food products “The performance characteristic of the

food will likely change when exposed to these temperatures and time. Wheat does not mill as well. Flour does not bake as well and we know what happens to chocolate.”

Things do dry out

Heat Treatment Considerations

Before

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Preparation immediate to a heat up– cleaning– seal building– insecticide residual application– placing air circulators and heaters– placing thermometers and

hygrometers– placing insect test cages– placard warning on entry doors

Heat Treatment Considerations

Before

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Monitoring during a heat treatment–Buddy system - pairs

»Keep an eye on the place AND each other

–Data collection»Temperature and Humidity

Remote minimizes time in the heat

»Insect mortality

Heat Treatment Considerations

During

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Buddy System

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Worker Safety Provisions– clothing, no metal

»buttons, glasses, etc.– established routes with flashlights– rest area with first aid, emergency phone

numbers– cool vests available for emergencies

Monitoring, adjusting heaters, fans and reporting activities are necessary

Heat Treatment Considerations

During

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Cool downCollection of monitoring equipmentOperational start up

– Process flush out … insect fragments may be highLook for

– plastic material sagging– leaks – lubricants, seals– peeling of old paint– dead insect accumulations lead to unknown

sources

Heat Treatment Considerations

After

Document for Future Reference

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Resources

Internal

Outside Services– “Think Outside The

Box”

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Rule of the “E’s” –1. Experiment and Learn

–2. Become Effective and Efficacious

–3. Become Efficient and Economical

Heat Treatment Considerations

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WARNING

HEAT STRESS

AREA

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A Heat Treatment ProfileAverage temperature by floor

Tem

pera

ture

(D

eg. F

)

Time

60

70

80

90

100

110

120

130

140

150

16011

:30

AM

1:30

PM

3:30

PM

5:30

PM

7:30

PM

9:30

PM

12:1

5 A

M

1:15

AM

3:30

AM

5:00

AM

6:30

AM

8:00

AM

10:0

0 A

M

12:0

0 P

M

2:30

PM

4:00

PM

5:30

PM

7:30

PM

Floor 6

Floor 5

Floor 4

Floor 3

Floor 2

Floor 1

Outside

Lethal Duration

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Is there a temperature difference inside equipment during a heat treatment?

Heat Treatment Considerations

A slight difference and a cool down delay does exist.

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A Heat Treatment Experiment

Average temperature inside and outside sifters

Tem

pera

ture

(D

eg. F

)

60708090

100110120130140150160

6:00 PM 5:00 AM 12:00 PM 4:00 PM

Inside

Outside

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Heat Treatment Experiment Flour Beetle Mortality

Inside sifters

Per

cent

60708090

100110120130140150160

6:00 PM 5:00 AM 12:00 PM 4:00 PM

Inside

Outside

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Heat Treatment Experiment Flour Beetle Mortality

Inside Sifters

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67

0

100

0

100

0

10

20

30

40

50

60

70

80

90

100

8 Hours 12 Hours 16 Hours

Live

Dead

Per

cent

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SummaryHeat is Effective!Heat Supports IPM!Heat is a Back to Future Concept!Be Prepared! Better Than Some Alternatives =

Heat Treatment Considerations

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Information or Knowledge

Information Overload?

One Must Make Some Knowledge Out Of The Information– Or be overloaded

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Yes, Thank You

Are We Done Yet?