QAL Category M Exam NEWEST 2026 | 100%
Verified & Updated Detailed Answers |
GRADED A+ best testbank 2025
What is a fumigant
• Gases liquid, solids
• Odorless and invisible
• Toxic when absorbed or inhaled
• Spread & penetrate spaces & materials
• Non-selective pesticide (kills all)
• Concentration, time, temp & humidity
• No residual or post application protection
• Forms
• Cylinders
• CO2: Carbon Dioxide: treat stored commodities, containment
structures, and outdoor burrowing rodents
• SO2: sulfur dioxide: wine barrels, corks, certain commodities
Pros vs Cons
• PROS
• Toxic to all pests
• Reach pest otherwise hard to locate, apply other pesticides
• Can kill pest on/near foods w/o residual
• Practical way to kill commodity pests
• CONS
• Very toxic
• No post application protection
• Expensive PPE
• Applicators must be skilled: labor cost high
,• Applications require supervision to be effective
Common fumigants:
• Sulfuryl fluoride
• Carbon Dioxide (CO2)
• Methyl bromide
• MITC & MITC generating fumigants
• Sulfur Dioxide (SO2)
Fumigant distribution in a space
• Molecular weight: measure of the weight of the atoms that forma
particular substance
• Specific gravity: ratio of the density of a substance to the density of a
standard
• Standard for gas = 1
• Greater then 1 = heavier than air, sinks
• Less then 1 = lighter than air, rises
• MW and SG: tell you
• SF = 3.52
• Labeled required fans to evenly distribute AI
Volatility & Vapor pressure
• Volatility: describes how a substance turns to vapor
• Vapor: measurement of the push against the atmosphere
• Vapor pressure: pressure stabilize at a constant value
• Higher vapor pressure = more concentrated = better fumigant
Solubility, Flammability, Reactivity
• Solubility: measure of how gas will dissolve into other materials
• Highly soluble fumes will dissolve in high moisture/oil content
commodities
• Flammability: capacity to catch fire
• Reactivity: reaction with products
• Methyl Bromide: sulfur products: foul odor hard to eliminate
• Phosphine: copper: corrosion, flammable
Sorption: Absorption & Desorption
,• Absorption: gas stick to surfaces, penetrate material
• Desorption: release of gas
• More surface area (rice) = more absorptive
• Inert surfaces (metal) = less absorptive
• ** Aeration must be long enough for fumigant to desorb
• Not enough time= tainted commodities: toxic residues, off taste and
odors
Phosphine, AP, MP
• Restrictive use materials, permits required
• Reactive with moisture = toxic gas
• Warmth and humidity increase reaction rate
• May be pure or mixed with CO2
• Can not be re-used, product or metal flask
• Precautions
• Fire risk is produced quickly, mixed with CO2 not flammable
• Explosive above 18,000 ppm
• AP cannot be used within 100 feet of structure
Sulfuryl fluoride
• Properties
• Colorless, odorless, non-flammable
• Corrosive in presence of open flames
• Desorbs quickly
• Effective on larva & adults not eggs
• Fans use to distribute gas
• Chloropicrin: warning agent
CO2
• Colorless, odorless, non-flammable, no residue
• Naturally occurring
• Commodities, burrowing rodent control
MB: Methyl bromide
• Colorless, odorless gas, pressured liquid cylinders
• Heavier than air = must use fans to distribute
• Green house gas, use phasing out
, • Never: use near open flames, salt, damages seeds
• Avoid use around rubber products and PPE
MITC (metam sodium, Dichlobenil)
• Metam is a MITC gas generator: upon exposure degrades to form MITC
gas
• Metam sodium: non-selective herbicide
• Dichlobenil: growth inhibitor
• uses: wood preservation, utility poles, leather processing, cane/sugar,
antimicrobial treatments, water purification, herbicide in sewers
SO2: Sulfur Dioxide
• Non-flammable smelly, liquid or gas
• Uses:
• Post harvest grapes held in cold storage, control gray mold disease,
sanitize corks/barrels
• Liquid SO2:
• Overdose barrels
• Cause respiratory hazard
• Acute respiratory toxin
• 20 psi or less = replace cylinder
Pest factors & Resistance
• Pest life stage
• Adults breath in more fumigant = metabolism effected by
temperatures
• Too cold or packed = don't breath as much
• Resistance
• Phosphine resistance: red & confused flour beetles, leer grain borer,
almond moth, cog beetle, IMMM, rusty grain beetle, sawtooth grain beetle
• Management:
• Practice IPM
• Fumigant only when necessary
• Rotate chemistry
Property Operator Permit conditions
Verified & Updated Detailed Answers |
GRADED A+ best testbank 2025
What is a fumigant
• Gases liquid, solids
• Odorless and invisible
• Toxic when absorbed or inhaled
• Spread & penetrate spaces & materials
• Non-selective pesticide (kills all)
• Concentration, time, temp & humidity
• No residual or post application protection
• Forms
• Cylinders
• CO2: Carbon Dioxide: treat stored commodities, containment
structures, and outdoor burrowing rodents
• SO2: sulfur dioxide: wine barrels, corks, certain commodities
Pros vs Cons
• PROS
• Toxic to all pests
• Reach pest otherwise hard to locate, apply other pesticides
• Can kill pest on/near foods w/o residual
• Practical way to kill commodity pests
• CONS
• Very toxic
• No post application protection
• Expensive PPE
• Applicators must be skilled: labor cost high
,• Applications require supervision to be effective
Common fumigants:
• Sulfuryl fluoride
• Carbon Dioxide (CO2)
• Methyl bromide
• MITC & MITC generating fumigants
• Sulfur Dioxide (SO2)
Fumigant distribution in a space
• Molecular weight: measure of the weight of the atoms that forma
particular substance
• Specific gravity: ratio of the density of a substance to the density of a
standard
• Standard for gas = 1
• Greater then 1 = heavier than air, sinks
• Less then 1 = lighter than air, rises
• MW and SG: tell you
• SF = 3.52
• Labeled required fans to evenly distribute AI
Volatility & Vapor pressure
• Volatility: describes how a substance turns to vapor
• Vapor: measurement of the push against the atmosphere
• Vapor pressure: pressure stabilize at a constant value
• Higher vapor pressure = more concentrated = better fumigant
Solubility, Flammability, Reactivity
• Solubility: measure of how gas will dissolve into other materials
• Highly soluble fumes will dissolve in high moisture/oil content
commodities
• Flammability: capacity to catch fire
• Reactivity: reaction with products
• Methyl Bromide: sulfur products: foul odor hard to eliminate
• Phosphine: copper: corrosion, flammable
Sorption: Absorption & Desorption
,• Absorption: gas stick to surfaces, penetrate material
• Desorption: release of gas
• More surface area (rice) = more absorptive
• Inert surfaces (metal) = less absorptive
• ** Aeration must be long enough for fumigant to desorb
• Not enough time= tainted commodities: toxic residues, off taste and
odors
Phosphine, AP, MP
• Restrictive use materials, permits required
• Reactive with moisture = toxic gas
• Warmth and humidity increase reaction rate
• May be pure or mixed with CO2
• Can not be re-used, product or metal flask
• Precautions
• Fire risk is produced quickly, mixed with CO2 not flammable
• Explosive above 18,000 ppm
• AP cannot be used within 100 feet of structure
Sulfuryl fluoride
• Properties
• Colorless, odorless, non-flammable
• Corrosive in presence of open flames
• Desorbs quickly
• Effective on larva & adults not eggs
• Fans use to distribute gas
• Chloropicrin: warning agent
CO2
• Colorless, odorless, non-flammable, no residue
• Naturally occurring
• Commodities, burrowing rodent control
MB: Methyl bromide
• Colorless, odorless gas, pressured liquid cylinders
• Heavier than air = must use fans to distribute
• Green house gas, use phasing out
, • Never: use near open flames, salt, damages seeds
• Avoid use around rubber products and PPE
MITC (metam sodium, Dichlobenil)
• Metam is a MITC gas generator: upon exposure degrades to form MITC
gas
• Metam sodium: non-selective herbicide
• Dichlobenil: growth inhibitor
• uses: wood preservation, utility poles, leather processing, cane/sugar,
antimicrobial treatments, water purification, herbicide in sewers
SO2: Sulfur Dioxide
• Non-flammable smelly, liquid or gas
• Uses:
• Post harvest grapes held in cold storage, control gray mold disease,
sanitize corks/barrels
• Liquid SO2:
• Overdose barrels
• Cause respiratory hazard
• Acute respiratory toxin
• 20 psi or less = replace cylinder
Pest factors & Resistance
• Pest life stage
• Adults breath in more fumigant = metabolism effected by
temperatures
• Too cold or packed = don't breath as much
• Resistance
• Phosphine resistance: red & confused flour beetles, leer grain borer,
almond moth, cog beetle, IMMM, rusty grain beetle, sawtooth grain beetle
• Management:
• Practice IPM
• Fumigant only when necessary
• Rotate chemistry
Property Operator Permit conditions
