Section 3B. Physical/Chemical Properties

Question 1

The three factors that influence the movement of gases.

Answer 1

Ventilation systems or wind
Temperature
Vapor Density

Question 2

What is vapor density?

Answer 2

The weight of the materials vapor relative to air, air having a v.p. of 1.0.

Question 3

What is meant by miscibility or solubility?

Answer 3

These terms denote whether one material will mix with, or dissolve in, another. In the Hazmat world, we assume one of the materials to be water. When we say something is soluble (or miscible), it will mix. If it is not soluble or miscible it will either float or sink in the water.

Question 4

What is meant by specific gravity?

Answer 4

The weight of a liquid compared to the weight of water. Water is assigned a specific gravity value of 1.

Question 5

What is meant by viscosity?

Answer 5

This term relates to the ability of the material to be mobile and migrate (i.e. it’s liquidity).

Question 6

What are 30-second rules?

Answer 6

They are things that you need to remember during the first 30 seconds of any incident involving hazardous materials.

Question 7

What’s the first 30-second rule?

Answer 7

If the material involved in the clean up activity or spill is a flammable or combustible liquid such as one marked with the placard or label shown, the vapors will be heavier than air.

Question 8

Second 30-second rule.

Answer 8

If the material involved in the clean up or spill is a flammable or combustible material, the liquid will not be heavier than water (s.g. = 1.0) or it will mix with water (.i.e. it is soluble or miscible in water). In either case, adding water to a flammable or combustible material will generally make the situation worse.

Question 9

Third 30-second rule.

Answer 9

Materials that are not on the H-A-H-A-M-I-C-E list are almost always heavier than air.

Question 10

Name the gases represented by:

H-A-H-A-M-I-C-E

Answer 10

Hydrogen
Anhydrous Ammonia
Helium
Acetylene
Methane
Illuminating Gases
Carbon monoxide
Ethylene

Question 11

What are the illuminating gases?

Answer 11

Gases which illuminate or light up, such as neon.
Natural gas, which is not all methane, was actually used in street lights at the turn of the century.
Hydrogen Cyanide is the third one in the list and takes a little more explanation and a bit of mind stretching to understand why it fits. Well, one of the things that we use HCN for is to execute convicted persons in the gas chamber. Pardon the very sick humor, but when the convict is exposed to the gas, there is a brief moment where they “see the light.” I told you it was a bit sick, but I bet you will not forget it

Question 12

Fourth 30-second rule.

Answer 12

You can select the proper level of protection for handling a specific chemical by looking at the NFPA health rating. (NOT perfect!)

Question 13

PPE Level if H = 0 or 1?

Answer 13

Level D

Question 14

PPE level if H = 2?

Answer 14

Level C

Question 15

PPE level if H = 3?

Answer 15

Level B

Question 16

PPE level if H = 4?

Answer 16

Level A

Question 17

Fifth 30-second rule.

Answer 17

Oxidizers, when part of any spill or clean up project, almost always make the situation worse and could create a safety hazard for workers.

Question 18

Some ways to determine if an oxidizer is involved.

Answer 18

1. Simply ask if an oxidizer is involved in the incident. If so, expect the worst.
2. If the material ends in “ate” or “ite”, or has “per” “oxy” or “hypo” in its name, it might be an oxidizer.