CALIFORNIA DPR NON SOIL
FUMIGATION EXAM PREP 100 PRACTICE
QUESTIONS and RATIONALES
CATEGORY 1B LICENSE STUDY GUIDE
2025
DPR Non-Soil Fumigation Examination Prep:
Questions
1. What is the primary definition of "non-soil fumigation"
under California Department of Pesticide Regulation
(DPR) guidelines? A. The application of pesticides to
control weeds in agricultural fields. B. The use of gaseous
pesticides to control pests in structures, commodities, or
enclosed spaces, excluding agricultural soil. Correct
Answer: B Rationale: Non-soil fumigation
specifically refers to the use of fumigants in structures
(like buildings and ships), commodities (like grains and
nuts), and other enclosed spaces, distinct from soil
fumigation used for pre-plant pest control. C. The
spraying of liquid pesticides on the foliage of crops. D. The
injection of gases into irrigation systems.
2. Which of the following is the most commonly used
fumigant for whole-structure (tent) fumigation in
California? A. Methyl bromide B. Sulfuryl fluoride
(Vikane) Correct Answer: B Rationale: Sulfuryl
fluoride is the primary fumigant used for structural
fumigation in California due to its effectiveness against
wood-destroying organisms like drywood termites and
its lack of ozone-depleting properties. C. Phosphine D.
Metam sodium
,3. What is the primary purpose of adding chloropicrin to a
fumigation application? A. To increase the toxicity of the
fumigant to insects. B. To act as a warning agent because it
is a severe lacrimator (tear-producing chemical).
Correct Answer: B Rationale: Chloropicrin is
added to odorless fumigants (like sulfuryl fluoride or
methyl bromide) as a warning agent. Its strong,
irritating effect on the eyes and respiratory tract alerts
individuals to the presence of the fumigant. C. To
neutralize the fumigant during aeration. D. To prevent the
fumigant from degrading in sunlight.
4. Before beginning a structural fumigation, what is the
legally required action regarding neighbors? A. No
notification is required if the structure is detached. B.
Provide written notification to all occupants and adjacent
occupants within the specified buffer zone prior to
fumigation. Correct Answer: B Rationale:
California regulations mandate that both the occupants
of the structure being fumigated and the occupants of
adjacent structures within the buffer zone must be
notified in writing before the fumigation begins. C. Only
notify the local fire department. D. Post a sign on the
property line 24 hours after fumigation begins.
5. What type of respiratory protection is generally required
for a fumigator handling sulfuryl fluoride cylinders during
application? A. No respiratory protection is needed if
working outdoors. B. A NIOSH-approved self-contained
breathing apparatus (SCBA) or a supplied-air respirator.
Correct Answer: B Rationale: Due to the high
toxicity and odorless nature of sulfuryl fluoride, an SCBA
or supplied-air respirator is required when there is a
potential for exposure above the permissible exposure
limit, such as when connecting or disconnecting
, cylinders. C. A simple N95 dust mask. D. A half-face
respirator with organic vapor cartridges.
6. What is the minimum required clearance time before re-
entry into a structure fumigated with sulfuryl fluoride? A.
Immediately after the fans are turned off. B. When the
fumigator determines the concentration is safe, but no less
than the time specified on the product label and
regulations (typically requiring specific aeration and
clearance testing). Correct Answer: B Rationale:
Re-entry is only permitted after the structure has been
thoroughly aerated and a certified fumigator has tested
the air to confirm that sulfuryl fluoride levels are at or
below the allowable clearance level (e.g., 1 ppm). C. 12
hours after the tarp is removed. D. 24 hours regardless of
air monitoring results.
7. Which of the following commodities is commonly
fumigated with phosphine gas? A. Fresh leafy vegetables
B. Stored grains and nuts Correct Answer: B
Rationale: Phosphine (generated from aluminum or
magnesium phosphide) is widely used for fumigating
stored agricultural commodities like grains, nuts, and
dried fruits to control internal and external insect pests.
C. Live potted plants D. Fresh meat products
8. What is the primary environmental concern associated
with methyl bromide? A. It causes severe soil erosion. B. It
is a potent ozone-depleting substance. Correct
Answer: B Rationale: Methyl bromide is a Class I
ozone-depleting substance. Its use is heavily restricted
and phased out globally under the Montreal Protocol,
with very few critical-use exemptions remaining. C. It is
highly flammable. D. It causes immediate groundwater
contamination.
, 9. When calculating the dosage of a fumigant for a structure,
which factor must be adjusted for if the temperature is
unusually low? A. The dosage must be decreased. B. The
dosage must be increased to compensate for reduced
fumigant volatility and pest activity. Correct Answer:
B Rationale: Fumigant labels provide temperature
correction factors. At lower temperatures, the fumigant is
less volatile and pests have slower metabolisms,
requiring a higher dosage or longer exposure time to
achieve mortality. C. The temperature has no effect on
fumigant dosage. D. The fumigation must be canceled if
the temperature is below 70°F.
10. What is the purpose of "sealing" a structure prior to
fumigation? A. To keep the fumigant from escaping and to
prevent unauthorized entry. Correct Answer: A
Rationale: Sealing (using tarps, sealants, and locking
mechanisms) contains the fumigant at the required
concentration for the necessary exposure time and
prevents people or pets from accidentally entering the
hazardous environment. B. To prevent rain from
damaging the interior of the structure. C. To keep insects
from entering the structure during fumigation. D. To
improve the aesthetic appearance of the building.
11. Which agency is primarily responsible for enforcing
fumigation regulations in California? A. The
Environmental Protection Agency (EPA) only. B. The
California Department of Pesticide Regulation (DPR) and
local County Agricultural Commissioners (CAC).
Correct Answer: B Rationale: While the EPA
registers the pesticides, the California DPR sets state-
specific regulations, and local County Agricultural
Commissioners are the primary enforcers of these
regulations at the local level. C. The Occupational Safety
FUMIGATION EXAM PREP 100 PRACTICE
QUESTIONS and RATIONALES
CATEGORY 1B LICENSE STUDY GUIDE
2025
DPR Non-Soil Fumigation Examination Prep:
Questions
1. What is the primary definition of "non-soil fumigation"
under California Department of Pesticide Regulation
(DPR) guidelines? A. The application of pesticides to
control weeds in agricultural fields. B. The use of gaseous
pesticides to control pests in structures, commodities, or
enclosed spaces, excluding agricultural soil. Correct
Answer: B Rationale: Non-soil fumigation
specifically refers to the use of fumigants in structures
(like buildings and ships), commodities (like grains and
nuts), and other enclosed spaces, distinct from soil
fumigation used for pre-plant pest control. C. The
spraying of liquid pesticides on the foliage of crops. D. The
injection of gases into irrigation systems.
2. Which of the following is the most commonly used
fumigant for whole-structure (tent) fumigation in
California? A. Methyl bromide B. Sulfuryl fluoride
(Vikane) Correct Answer: B Rationale: Sulfuryl
fluoride is the primary fumigant used for structural
fumigation in California due to its effectiveness against
wood-destroying organisms like drywood termites and
its lack of ozone-depleting properties. C. Phosphine D.
Metam sodium
,3. What is the primary purpose of adding chloropicrin to a
fumigation application? A. To increase the toxicity of the
fumigant to insects. B. To act as a warning agent because it
is a severe lacrimator (tear-producing chemical).
Correct Answer: B Rationale: Chloropicrin is
added to odorless fumigants (like sulfuryl fluoride or
methyl bromide) as a warning agent. Its strong,
irritating effect on the eyes and respiratory tract alerts
individuals to the presence of the fumigant. C. To
neutralize the fumigant during aeration. D. To prevent the
fumigant from degrading in sunlight.
4. Before beginning a structural fumigation, what is the
legally required action regarding neighbors? A. No
notification is required if the structure is detached. B.
Provide written notification to all occupants and adjacent
occupants within the specified buffer zone prior to
fumigation. Correct Answer: B Rationale:
California regulations mandate that both the occupants
of the structure being fumigated and the occupants of
adjacent structures within the buffer zone must be
notified in writing before the fumigation begins. C. Only
notify the local fire department. D. Post a sign on the
property line 24 hours after fumigation begins.
5. What type of respiratory protection is generally required
for a fumigator handling sulfuryl fluoride cylinders during
application? A. No respiratory protection is needed if
working outdoors. B. A NIOSH-approved self-contained
breathing apparatus (SCBA) or a supplied-air respirator.
Correct Answer: B Rationale: Due to the high
toxicity and odorless nature of sulfuryl fluoride, an SCBA
or supplied-air respirator is required when there is a
potential for exposure above the permissible exposure
limit, such as when connecting or disconnecting
, cylinders. C. A simple N95 dust mask. D. A half-face
respirator with organic vapor cartridges.
6. What is the minimum required clearance time before re-
entry into a structure fumigated with sulfuryl fluoride? A.
Immediately after the fans are turned off. B. When the
fumigator determines the concentration is safe, but no less
than the time specified on the product label and
regulations (typically requiring specific aeration and
clearance testing). Correct Answer: B Rationale:
Re-entry is only permitted after the structure has been
thoroughly aerated and a certified fumigator has tested
the air to confirm that sulfuryl fluoride levels are at or
below the allowable clearance level (e.g., 1 ppm). C. 12
hours after the tarp is removed. D. 24 hours regardless of
air monitoring results.
7. Which of the following commodities is commonly
fumigated with phosphine gas? A. Fresh leafy vegetables
B. Stored grains and nuts Correct Answer: B
Rationale: Phosphine (generated from aluminum or
magnesium phosphide) is widely used for fumigating
stored agricultural commodities like grains, nuts, and
dried fruits to control internal and external insect pests.
C. Live potted plants D. Fresh meat products
8. What is the primary environmental concern associated
with methyl bromide? A. It causes severe soil erosion. B. It
is a potent ozone-depleting substance. Correct
Answer: B Rationale: Methyl bromide is a Class I
ozone-depleting substance. Its use is heavily restricted
and phased out globally under the Montreal Protocol,
with very few critical-use exemptions remaining. C. It is
highly flammable. D. It causes immediate groundwater
contamination.
, 9. When calculating the dosage of a fumigant for a structure,
which factor must be adjusted for if the temperature is
unusually low? A. The dosage must be decreased. B. The
dosage must be increased to compensate for reduced
fumigant volatility and pest activity. Correct Answer:
B Rationale: Fumigant labels provide temperature
correction factors. At lower temperatures, the fumigant is
less volatile and pests have slower metabolisms,
requiring a higher dosage or longer exposure time to
achieve mortality. C. The temperature has no effect on
fumigant dosage. D. The fumigation must be canceled if
the temperature is below 70°F.
10. What is the purpose of "sealing" a structure prior to
fumigation? A. To keep the fumigant from escaping and to
prevent unauthorized entry. Correct Answer: A
Rationale: Sealing (using tarps, sealants, and locking
mechanisms) contains the fumigant at the required
concentration for the necessary exposure time and
prevents people or pets from accidentally entering the
hazardous environment. B. To prevent rain from
damaging the interior of the structure. C. To keep insects
from entering the structure during fumigation. D. To
improve the aesthetic appearance of the building.
11. Which agency is primarily responsible for enforcing
fumigation regulations in California? A. The
Environmental Protection Agency (EPA) only. B. The
California Department of Pesticide Regulation (DPR) and
local County Agricultural Commissioners (CAC).
Correct Answer: B Rationale: While the EPA
registers the pesticides, the California DPR sets state-
specific regulations, and local County Agricultural
Commissioners are the primary enforcers of these
regulations at the local level. C. The Occupational Safety
