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Heat Treatment Considerations
Before – AfterOle Dosland
Director of Technical Training& E-Learning
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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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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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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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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
33
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