Using FMP’s for a
Structural Fumigation
Cecil Tharp
MSU Pesticide Education Specialist
FMP’s must be written prior to
fumigations
Pre-Inspection
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Inspect the structure and/or area to
determine suitability for fumigation.
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Leaks
Hazards: Proximity to other individuals
/ structures / or animals
Urban Residence or Rural Residence?
Storage Sealing Materials
Seal Aeration Fan Motors
Seal Aeration Fan Inlets
Seal Steel Bin Roof Eaves
Seal Steel Bin Door
Create a diagram or sketch of the
fumigation site: identify hazards
Create a Monitoring Plan:
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Keep a log or manual of monitoring records for
each fumigation site.
What will you do if you have leaks?
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How do you monitor; placement?
What do you do when you have leaks
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>.3 ppm (Emergency Contact; PPE)
> 15 ppm (Emergency Contact; PPE)
Multiple and single gas detectors
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Several Manufacturers
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Lumidor
Dräger
Analytical Tech., Inc.
MSA
Toxirae
Others
FMP -- Continued
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Placard all entrances to site
Give owner and other workers a copy:
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FMP
MSDS
The number and identification of persons
who routinely enter the area to be
fumigated and the proximity of other
persons and animals.
Current emergency telephone numbers
of local Health, Fire, Police, Hospital and
Physician
*Determining Product Rates
Step #1: Determining Volume
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π = 3.14
r = Radius = ½
Diameter
D = Diameter
C = Circumference =
πD
Determine volume: Cylinder
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Formula: volume = 3.14 x r2 x H
r = ½D
3.14′ x (13.5′ x 13.5′) x 16′ = 9,156 Ft3
Volume: Cylinder when only
circumference is known
Circumference = 84.78’
Diameter = Circumference
------------------3.14
Diameter = 84.78 / 3.14  Diameter = 27  Radius = 13.5 feet
Formula: volume = 3.14 x r2 x H
3.14′ x (13.5′ x 13.5′) x 16′
volume = 9,156 cubic feet
Volume of ½ cylinder
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Volume = (3.14 x r2 x H) / 2
Calculating Volume: Cone
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1.047 x radius2 x height
 1.047 x 182.25 x 16
Volume = 3,053 cubic ft
Calculating Volume of Rectangle or
Triangles
Rectangle volume = L x W x H
Triangle (Loft) Formula = (L x W x H) ÷ 2
Base Volume: 80′ x 20′ x 20′ = 32,000 cubic ft
Loft Volume: (80′ x 20′ x 10′) = 16,000 ÷ 2 = 8,000 cubic ft
Total Volume: 32,000 + 8,000 = 40,000 Ft3
Step #2: Determine amount of fumigant to
add to your application site
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Refer to product label
recommendations
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Tablets or Pellets Per 1,000
square feet
Tablets or Pellets per 1,000
bushels
Usually expressed as
range
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You must determine what
part of range is best
 Leaks
 Moisture
 Tarped
Story Problem. An inspector was called out to help
an applicator figure out how many phostoxin pellets to
place in a grain silo. The silo has an 80’
circumference, 25’ height from eaves to ground, and 5’
high cone. Temperature is 80 degrees F. This silo also
contains 500 bushels of grain.
Story Problem: Answers
1. Total Volume of Silo?
Diameter = 80 / 3.14  Diameter = 25.47  Radius = 25.47 / 2  Radius = 12.73
Cylinder = 3.14 x 12.732 x 25  Cylinder = 3.14 x 162.05 x 25  Cylinder = 12,721 ft3
Cone = 1.047 x 162.05 x 5  Cone = 848.33 cubic ft.
Total Volume = 848.33 + 12,721  13,569.33 cubic ft
2. How many pellets need to be used?
 450 – 900 pellets / 1,000 bu withtarp500 bushel  225 – 450 pellets
 350 – 725 pellets / 1,000 ft3  no tarp  4,749 – 9,837.33 pellets
* Ranges with severity of infestation, leaks, tarp etc…
3. How long before aeration?
 48 hours
Take 20 minutes: Do story problem titled ‘Jordon’s Feed
Mill story problem’ (Work in groups using Product Label)
Jordon’s Feed Mill Story Problem
Jordon’s Feed Mill has a grain silo that is 75’ in circumference and a
vertical distance from the eaves to the bottom of the bin of 15’. The
cone top is 3’ high. Larry’s Pest Control has been contracted to
fumigate one of the silos for the lesser grain borer. The silo is filled
with approximately 500 bushels of spring wheat. Larry can either
fumigate on Tuesday July 21st in the evening, or Thursday July 23rd in
the evening. The weather for Tuesday is forecast to be partly cloudy
with a 70% chance of rain and a high of 95 degrees F. Thursday is
forecast to be sunny with a temperature of 101 degrees F. The peak
grain temperature ranges from 70 – 80 degrees F. There are horses
50 yards from grain silo. Detail your fumigation management plan
strategy to include at least the following details.
‘Jordon’s Feed Mill story problem’
1. What is the volume of this grain bin?
Diameter = 75 / 3.14  Diameter = 23.88  Radius = diameter / 2  Radius =
11.94
– cyl = 3.14 x 11.942 x 15  volume = 3.14 x 142.45 x 15  volume = 6,714.74
cubic ft
– cone = 1.047 x 11.942 x 3  cone = 447.43 cubic ft
– Volume = 447.43 + 6,714.74  Volume = 7,162.17 cubic ft
2. How many pellets will you need to use when fumigating?
-450 – 900 pellets / 1,000 bu  with tarp  500 bushel  225 – 450 pellets
-350 – 725 pellets / 1,000 ft3  no tarp  2,506 – 5,192.45 pellets
* Ranges with severity of infestation, leaks, etc…
3. Calculate the required fumigation period based on fumigant grain
temperature?
-48 hr  60 – 80 degrees F grain temperature  if sealed properly
Review Fumigant Management
Plans
4. Which day would be the best one to start the fumigation?
-Tuesday July 21st because of moisture that afternoon. Moisture
will helps convert aluminum or magnesium phosphide into
phosphine gas.
5. When should ventilation begin?
-Thursday evening or Friday morning, < 0.3 ppmillion
6. What personal protective equipment should you wear and how does
this relate phosphine gas concentrations?
-wear dry cotton gloves, wash after, respiratory equipment (NIOSH /
phosphine gas approved)-up to 15 ppm
Questions?
MSU Pesticide Education:
www.pesticides.montana.edu
Degesch America:
www.degeschamerica.com
Detector Tubes
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ADVANTAGES
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Initial low cost
Variety of tubes
Variety of ranges
Easy to use
No calibration
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DISADVANTAGES
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Point in Time reading
Must know gas
$4 to $9/reading
Expiration Date
Disposal
High Std. Deviation
Glass tubes
Pumps can malfunction
Operator error
Color can fade after
reading