Question 1

All combustible liquids are Class II liquids.

Accepted Answer

Combustible liquids are classified into Class II, Class IIIA, and Class IIIB, based on their flash points and boiling points, not all are Class II.

Question 2

Classification of flammable liquids does not depend upon boiling point.

Accepted Answer

Classification of flammable liquids does take into account the boiling point among other factors such as flash point, because the boiling point can influence the vapor pressure and the rate at which a liquid produces flammable vapors.

Question 3

Class III B liquids are not classified by OSHA standards as "hazardous substances."

Accepted Answer

Class III B liquids are not considered hazardous substances by OSHA standards because they have a low potential for causing harm to human health or the environment.

Question 4

Which of the following is best classified as a Class B explosive?
A)nitroglycerin
B)dynamite
C)black powder
D)propellant

Accepted Answer

Propellants are classified as Class B explosives, which are less hazardous than Class A explosives like nitroglycerin and dynamite. Black powder is typically classified as a low explosive.

Question 5

All Class I liquids are flammable liquids.

Accepted Answer

Class I liquids, also known as flammable liquids, include substances with flashpoints less than 100°F (37.8°C). Therefore, all Class I liquids are flammable liquids.

Question 6

The ignition temperature for gasoline is higher than for paper.

Accepted Answer

Gasoline has a higher ignition temperature than paper, which means it requires more heat or a spark to ignite. This is due to the chemical composition of gasoline, which includes hydrocarbons that have a higher flashpoint compared to the cellulose fibers in paper.

Question 7

What two physical characteristics of a liquid are principally used to determine its flammability classification?
A)flashpoint and boiling point
B)flashpoint and firepoint
C)boiling point and firepoint
D)volatility and boiling point

Accepted Answer

Flashpoint is the lowest temperature at which a liquid can form an ignitable mixture with air near the surface of the liquid. Boiling point is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor. These two properties are used to determine the flammability classification of a liquid because they indicate the relative ease with which a liquid can be ignited and the temperature range over which it can burn.

Question 8

Which of the following is best classified as a Class C explosive?
A)black powder
B)propellant
C)photographic flash powder
D)explosive rivets

Accepted Answer

Class C explosives are those that contain Class A or Class B explosives, or both, as components but in restricted quantities. Explosive rivets are typically classified as Class C because they contain small amounts of explosive material.

Question 9

All flammable liquids are Class I liquids.

Accepted Answer

This statement is true. Flammable liquids are classified as Class I liquids according to the National Fire Protection Association (NFPA) system.

Question 10

Which of the following is best classified as a Class A explosive?
A)black powder
B)propellant
C)photographic flash powder
D)explosive rivets

Accepted Answer

Black powder is a Class A explosive due to its sensitivity to heat and friction, high explosive power, and likelihood of accidental detonation. Propellant, photographic flash powder, and explosive rivets are classified as Class B explosives, which are less sensitive and less likely to cause accidental detonation.

Question 11

Some flammable liquids are Class III liquids.

Accepted Answer

The answer of Some flammable liquids are Class III liquids....

Question 12

What principal physical characteristic of gasoline makes it particularly hazardous to have basements in service stations?

Accepted Answer

The answer of What principal physical characteristic of gasoline makes...

Question 13

The definition of "liquid" by NFPA as far as flammable liquids are concerned has little to do with vapor pressure.

Accepted Answer

The NFPA (National Fire Protection Association) defines flammable liquids based on their flash point and boiling point, which are directly related to vapor pressure.

Question 14

Flashpoint is the temperature at which a fire on top of the liquid is sustained.

Accepted Answer

Flashpoint is the temperature at which a liquid gives off enough vapor to ignite momentarily if exposed to a flame, but it is not the temperature at which a fire on top of the liquid is sustained.

Question 15

All combustible liquids are Class III liquids.

Accepted Answer

Combustible liquids are divided into Class II and Class III liquids based on their flash points, with Class III further subdivided into Class IIIA and Class IIIB.

Question 16

What is the principal criterion for determining whether wiring for flammable paint spray areas must be Class I Division 1 or Division 2?

Accepted Answer

The answer of What is the principal criterion for determining...

Question 17

The proper wiring selection for areas twenty feet or more away from flammable paint spray booths is:
A)Class I,Division 1
B)Class I,Division 2
C)Class II,Division 1
D)conventional wiring

Accepted Answer

Conventional wiring is permitted in areas twenty feet or more away from flammable paint spray booths.

Question 18

All Class II liquids are combustible liquids.

Accepted Answer

Class II liquids are defined as liquids with flashpoints above 100°F but below 140°F. All liquids with flashpoints in this range are considered combustible, making the statement true.

Question 19

What two physical characteristics of a liquid are principally used to determine its flammability classification?

Accepted Answer

The answer of What two physical characteristics of a liquid...

Question 20

Volatility of a liquid bears a close relationship to the boiling point of a liquid.

Accepted Answer

The volatility of a liquid refers to how easily it evaporates or turns into a vapor. The higher the boiling point of a liquid, the less volatile it is because more heat energy is required to break its molecular bonds and turn it into a gas. Conversely, liquids with low boiling points are highly volatile because they require less heat energy to turn into a gas. Therefore, there is a direct relationship between a liquid's volatility and its boiling point.

Quiz 11: Flammable and Explosive Materials

All combustible liquids are Class II liquids.

Classification of flammable liquids does not depend upon boiling point.

Class III B liquids are not classified by OSHA standards as "hazardous substances."

Which of the following is best classified as a Class B explosive?

All Class I liquids are flammable liquids.

The ignition temperature for gasoline is higher than for paper.

What two physical characteristics of a liquid are principally used to determine its flammability classification?

Which of the following is best classified as a Class C explosive?

All flammable liquids are Class I liquids.

Which of the following is best classified as a Class A explosive?

Some flammable liquids are Class III liquids.

What principal physical characteristic of gasoline makes it particularly hazardous to have basements in service stations?

The definition of "liquid" by NFPA as far as flammable liquids are concerned has little to do with vapor pressure.

Flashpoint is the temperature at which a fire on top of the liquid is sustained.

All combustible liquids are Class III liquids.

What is the principal criterion for determining whether wiring for flammable paint spray areas must be Class I Division 1 or Division 2?

The proper wiring selection for areas twenty feet or more away from flammable paint spray booths is:

All Class II liquids are combustible liquids.

What two physical characteristics of a liquid are principally used to determine its flammability classification?

Volatility of a liquid bears a close relationship to the boiling point of a liquid.