QAL CATEGORY M EXAM QUESTIONS AND ALL
ANSWERS ARE CORRECT
A fumigant is defined as a gas, liquid, or solid.
• Invisible and odorless
• Non-selective pesticide (kills all); • Concentration, time, temperature, and
humidity; • Forms; • Cylinders; • Toxic when absorbed or inhaled; • Spreads
and penetrates spaces & materials;
• SO2: sulfur dioxide: wine barrels, corks, and certain commodities; CO2:
carbon dioxide: treat stored goods, containment structures, and outdoor
burrowing rats
Benefits and Drawbacks
Among its advantages are: • Toxic to all pests; • Able to kill pests on or near
meals without leaving any residue; • Reach pests that are ordinarily difficult to
discover; and A useful method for eliminating commodity pests
CONS
• Extremely hazardous; • No post-application protection; • Costly PPE; • Skilled
applicators are required: High personnel costs and the need for oversight for
applications to function
Common fumigants include sulfur dioxide (SO2), carbon dioxide (CO2),
methyl bromide, MITC, and fumigants that generate MITC.
Distribution of fumigants in a space
• Specific gravity is the ratio of a substance's density to a standard; the standard
for gas is 1; a value greater than 1 indicates that the substance is heavier than air
and sinks. • Molecular weight is the weight of the atoms that make up a specific
material.
Less than 1 means that it is lighter than air and rises.
MW and SG inform you that SF is 3.52 and that fans are needed to spread AI
, equally.
Both vapor pressure and volatility
• Volatility: explains the process by which a material turns into vapor.
A higher vapor pressure indicates a more concentrated fumigant; vapor pressure
measures the push against the atmosphere; and vapor pressure stabilizes at a
fixed value.
Reactivity, Flammability, and Solubility
• Flammability: the ability to catch fire; • Reactivity: the reaction with products;
• Solubility: the measure of how gas will dissolve into other materials; • Highly
soluble fumes will dissolve in commodities with high moisture or oil content
• Phosphine: copper: corrosion, combustible • Methyl bromide: sulfur products:
bad odor difficult to remove
Sorption: Absorption and Desorption; Absorption: gas adheres to surfaces and
penetrates material; Desorption: gas is released; More surface area (rice) equals
greater absorptivity
• Metal surfaces that are inert are less absorbent.
Aeration must last long enough for fumigant to desorb. If it doesn't, the products
will be polluted with harmful residues, odd flavors, and aromas.
MP, AP, and Phosphine
The following are some of the precautions: • Fire risk is generated quickly,
mixed with CO2 is not flammable; • AP is explosive above 18,000 ppm; •
Reactive with moisture = toxic gas; • Reactive with warmth and humidity
increase reaction rate; • May be pure or mixed with CO2; • Cannot be re-used,
product or metal flask; • Permits required;
Sulfuryl fluoride: Characteristics
It is colorless, odorless, and non-flammable; it corrodes when exposed to open
flames; it desorbs rapidly; it works on larvae and adults rather than eggs; fans
are used to disperse gas; and chloropicrin is a warning agent.
ANSWERS ARE CORRECT
A fumigant is defined as a gas, liquid, or solid.
• Invisible and odorless
• Non-selective pesticide (kills all); • Concentration, time, temperature, and
humidity; • Forms; • Cylinders; • Toxic when absorbed or inhaled; • Spreads
and penetrates spaces & materials;
• SO2: sulfur dioxide: wine barrels, corks, and certain commodities; CO2:
carbon dioxide: treat stored goods, containment structures, and outdoor
burrowing rats
Benefits and Drawbacks
Among its advantages are: • Toxic to all pests; • Able to kill pests on or near
meals without leaving any residue; • Reach pests that are ordinarily difficult to
discover; and A useful method for eliminating commodity pests
CONS
• Extremely hazardous; • No post-application protection; • Costly PPE; • Skilled
applicators are required: High personnel costs and the need for oversight for
applications to function
Common fumigants include sulfur dioxide (SO2), carbon dioxide (CO2),
methyl bromide, MITC, and fumigants that generate MITC.
Distribution of fumigants in a space
• Specific gravity is the ratio of a substance's density to a standard; the standard
for gas is 1; a value greater than 1 indicates that the substance is heavier than air
and sinks. • Molecular weight is the weight of the atoms that make up a specific
material.
Less than 1 means that it is lighter than air and rises.
MW and SG inform you that SF is 3.52 and that fans are needed to spread AI
, equally.
Both vapor pressure and volatility
• Volatility: explains the process by which a material turns into vapor.
A higher vapor pressure indicates a more concentrated fumigant; vapor pressure
measures the push against the atmosphere; and vapor pressure stabilizes at a
fixed value.
Reactivity, Flammability, and Solubility
• Flammability: the ability to catch fire; • Reactivity: the reaction with products;
• Solubility: the measure of how gas will dissolve into other materials; • Highly
soluble fumes will dissolve in commodities with high moisture or oil content
• Phosphine: copper: corrosion, combustible • Methyl bromide: sulfur products:
bad odor difficult to remove
Sorption: Absorption and Desorption; Absorption: gas adheres to surfaces and
penetrates material; Desorption: gas is released; More surface area (rice) equals
greater absorptivity
• Metal surfaces that are inert are less absorbent.
Aeration must last long enough for fumigant to desorb. If it doesn't, the products
will be polluted with harmful residues, odd flavors, and aromas.
MP, AP, and Phosphine
The following are some of the precautions: • Fire risk is generated quickly,
mixed with CO2 is not flammable; • AP is explosive above 18,000 ppm; •
Reactive with moisture = toxic gas; • Reactive with warmth and humidity
increase reaction rate; • May be pure or mixed with CO2; • Cannot be re-used,
product or metal flask; • Permits required;
Sulfuryl fluoride: Characteristics
It is colorless, odorless, and non-flammable; it corrodes when exposed to open
flames; it desorbs rapidly; it works on larvae and adults rather than eggs; fans
are used to disperse gas; and chloropicrin is a warning agent.
