Soil Fumigation Study Guide
Questions and Answers 2026 Updated.
Fumigants target: - Answer soil-borne insects, pathogens (e.g., nematodes, fungi, and
bacteria.
Soil pests are killed by exposure to either: - Answer A high enough concentration of the
fumigant or a lower concentration for a long enough time.
How does a fumigant move through soil? - Answer Fumigants can be applied as a dry
granule, liquid, or liquefied gas but volatilize once in the soil. The gaseous molecules move
through the soil pores and some molecules dissolve into the soil water. Some products may
move through soil pores or soil water.
How does Methyl Bromide, iodomethane, and 1,3-dichloropropene move through the soil
profile? - Answer These fumigants move through soil primarily as a gas and are sometimes
referred to as true fumigants. These chemicals move thousands of times faster through soil
pores than they do soil water.
How does metam sodium, metam potassium, and dazomet move through the soil? - Answer
These fumigants readily move as the parent compound to the zone of the target pest with
irrigation water or by mechanical incorporation. After exposure to water, these materials release
methyl isothiocyanate (MITC) gas, which kills nearby target pests.
What is the major risk to applicators and handlers when applying or handling fumigants? -
Answer Acute inhalation exposure caused by the chemical escaping from the soil.
General fumigant exposure symptoms include: - Answer -Watering, burning, or irritation of
the eyes, nose, or mucous membranes.
-Headache, nausea, or dizziness,
-Tremors, slurred speech, or loss of muscle coordination.
-Skin rash, burning, and/or blistering.
-Cough.
Monitoring requirements for non-water run fumigant applications: - Answer A certified
applicator must be present at the fumigation site and in the line of sight of the application and
fumigant handlers from the start of the application until the application is complete.
Monitoring requirements for water run fumigant applications (metam chemigation): - Answer
An applicator can leave the site once the application has begun, but must check back on the
Questions and Answers 2026 Updated.
Fumigants target: - Answer soil-borne insects, pathogens (e.g., nematodes, fungi, and
bacteria.
Soil pests are killed by exposure to either: - Answer A high enough concentration of the
fumigant or a lower concentration for a long enough time.
How does a fumigant move through soil? - Answer Fumigants can be applied as a dry
granule, liquid, or liquefied gas but volatilize once in the soil. The gaseous molecules move
through the soil pores and some molecules dissolve into the soil water. Some products may
move through soil pores or soil water.
How does Methyl Bromide, iodomethane, and 1,3-dichloropropene move through the soil
profile? - Answer These fumigants move through soil primarily as a gas and are sometimes
referred to as true fumigants. These chemicals move thousands of times faster through soil
pores than they do soil water.
How does metam sodium, metam potassium, and dazomet move through the soil? - Answer
These fumigants readily move as the parent compound to the zone of the target pest with
irrigation water or by mechanical incorporation. After exposure to water, these materials release
methyl isothiocyanate (MITC) gas, which kills nearby target pests.
What is the major risk to applicators and handlers when applying or handling fumigants? -
Answer Acute inhalation exposure caused by the chemical escaping from the soil.
General fumigant exposure symptoms include: - Answer -Watering, burning, or irritation of
the eyes, nose, or mucous membranes.
-Headache, nausea, or dizziness,
-Tremors, slurred speech, or loss of muscle coordination.
-Skin rash, burning, and/or blistering.
-Cough.
Monitoring requirements for non-water run fumigant applications: - Answer A certified
applicator must be present at the fumigation site and in the line of sight of the application and
fumigant handlers from the start of the application until the application is complete.
Monitoring requirements for water run fumigant applications (metam chemigation): - Answer
An applicator can leave the site once the application has begun, but must check back on the
