FDNY C42 Storage and Handling of Corrosives and
Oxidizers 2026 Exam Practice Questions – Questions
Verified Answers with Expert Rationales | 2026 Edition
Question 1:
Which of the following best defines a corrosive material?
A) A substance that releases oxygen rapidly
B) A material that causes destruction of living tissue or metals
C) A substance that only burns at high temperature
D) A non-reactive chemical compound
*Answer: * B) A material that causes destruction of living tissue or
metals
*Rationale: * Corrosives damage tissue and structural materials through
chemical action.
Question 2:
Which class best describes oxidizing agents?
A) Substances that react violently with water
B) Substances that yield oxygen to promote combustion of other materials
C) Substances with a pH less than 2
D) Substances that are always gases at room temperature
*Answer: * B) Substances that yield oxygen to promote combustion of
other materials
*Rationale: * Oxidizers provide oxygen or other oxidizing substances that
increase the burning rate and intensity of combustible materials.
,Question 3:
Oxidizers are dangerous because they:
A) Are flammable themselves
B) Can release oxygen and intensify fires
C) Are always explosive on contact with air
D) Neutralize acids
*Answer: * B) Can release oxygen and intensify fires
*Rationale: * Oxidizers may not be combustible, but they supply oxygen that
can accelerate the combustion of other materials.
Question 4:
A corrosive substance is one that:
A) Has a flash point below 100°F
B) Causes visible destruction or irreversible alterations in living tissue by
chemical action
C) Releases toxic gases when heated
D) Reacts violently with water
*Answer: * B) Causes visible destruction or irreversible alterations in
living tissue by chemical action
*Rationale: * This is the defining characteristic of corrosive materials
according to FDNY regulations.
Question 5:
Which of the following is considered a corrosive material?
,A) Water
B) Sulfuric acid
C) Sand
D) Glass
*Answer: * B) Sulfuric acid
*Rationale: * Corrosive materials can chemically destroy or irreversibly
damage another substance with which they come into contact, such as
sulfuric acid.
Question 6:
The primary hazard associated with corrosive materials is their ability to:
A) Release flammable vapors
B) React violently with water
C) Destroy living tissue and materials
D) Produce toxic smoke when heated
*Answer: * C) Destroy living tissue and materials
*Rationale: * Corrosives are defined by their ability to chemically damage or
destroy living tissue and materials on contact.
Question 7:
Oxidizers are dangerous because they:
A) Burn easily by themselves
B) Increase the burning rate of other materials
C) Neutralize flammable liquids
D) Prevent combustion
, *Answer: * B) Increase the burning rate of other materials
*Rationale: * Oxidizers support and intensify combustion by providing
oxygen or another oxidizing agent.
Question 8:
Which of the following is considered an oxidizer?
A) Sodium hydroxide
B) Potassium permanganate
C) Hydrochloric acid
D) Sulfuric acid
*Answer: * B) Potassium permanganate
*Rationale: * Potassium permanganate is a strong oxidizer that can react
violently with combustible materials.
Question 9:
Which material is NOT classified as a corrosive?
A) Sulfuric acid
B) Sodium hydroxide
C) Hydrochloric acid
D) Diesel fuel
*Answer: * D) Diesel fuel
*Rationale: * Diesel fuel is classified as a flammable or combustible liquid,
not a corrosive. Sulfuric acid, sodium hydroxide (caustic soda), and
hydrochloric acid are all corrosives.
Oxidizers 2026 Exam Practice Questions – Questions
Verified Answers with Expert Rationales | 2026 Edition
Question 1:
Which of the following best defines a corrosive material?
A) A substance that releases oxygen rapidly
B) A material that causes destruction of living tissue or metals
C) A substance that only burns at high temperature
D) A non-reactive chemical compound
*Answer: * B) A material that causes destruction of living tissue or
metals
*Rationale: * Corrosives damage tissue and structural materials through
chemical action.
Question 2:
Which class best describes oxidizing agents?
A) Substances that react violently with water
B) Substances that yield oxygen to promote combustion of other materials
C) Substances with a pH less than 2
D) Substances that are always gases at room temperature
*Answer: * B) Substances that yield oxygen to promote combustion of
other materials
*Rationale: * Oxidizers provide oxygen or other oxidizing substances that
increase the burning rate and intensity of combustible materials.
,Question 3:
Oxidizers are dangerous because they:
A) Are flammable themselves
B) Can release oxygen and intensify fires
C) Are always explosive on contact with air
D) Neutralize acids
*Answer: * B) Can release oxygen and intensify fires
*Rationale: * Oxidizers may not be combustible, but they supply oxygen that
can accelerate the combustion of other materials.
Question 4:
A corrosive substance is one that:
A) Has a flash point below 100°F
B) Causes visible destruction or irreversible alterations in living tissue by
chemical action
C) Releases toxic gases when heated
D) Reacts violently with water
*Answer: * B) Causes visible destruction or irreversible alterations in
living tissue by chemical action
*Rationale: * This is the defining characteristic of corrosive materials
according to FDNY regulations.
Question 5:
Which of the following is considered a corrosive material?
,A) Water
B) Sulfuric acid
C) Sand
D) Glass
*Answer: * B) Sulfuric acid
*Rationale: * Corrosive materials can chemically destroy or irreversibly
damage another substance with which they come into contact, such as
sulfuric acid.
Question 6:
The primary hazard associated with corrosive materials is their ability to:
A) Release flammable vapors
B) React violently with water
C) Destroy living tissue and materials
D) Produce toxic smoke when heated
*Answer: * C) Destroy living tissue and materials
*Rationale: * Corrosives are defined by their ability to chemically damage or
destroy living tissue and materials on contact.
Question 7:
Oxidizers are dangerous because they:
A) Burn easily by themselves
B) Increase the burning rate of other materials
C) Neutralize flammable liquids
D) Prevent combustion
, *Answer: * B) Increase the burning rate of other materials
*Rationale: * Oxidizers support and intensify combustion by providing
oxygen or another oxidizing agent.
Question 8:
Which of the following is considered an oxidizer?
A) Sodium hydroxide
B) Potassium permanganate
C) Hydrochloric acid
D) Sulfuric acid
*Answer: * B) Potassium permanganate
*Rationale: * Potassium permanganate is a strong oxidizer that can react
violently with combustible materials.
Question 9:
Which material is NOT classified as a corrosive?
A) Sulfuric acid
B) Sodium hydroxide
C) Hydrochloric acid
D) Diesel fuel
*Answer: * D) Diesel fuel
*Rationale: * Diesel fuel is classified as a flammable or combustible liquid,
not a corrosive. Sulfuric acid, sodium hydroxide (caustic soda), and
hydrochloric acid are all corrosives.
