Gas Exam - Part 2

Question 1

Explain the effects on a person with the following O2 concentrations -

18%

Answer 1

Gradual increase in breathing

Question 2

Explain the effects on a person with the following O2 concentrations -

12%

Answer 2

Considerably increased breathing rate and depth, especially with exertion.

Question 3

Explain the effects on a person with the following O2 concentrations -

<10%

Answer 3

Nausea, headaches, lips turn blue, may collapse, mental confusion, loss of consciousness

Question 4

What is the minimum General body concentration of O2 a CMW can be exposed to?

Answer 4

19% General Body

Question 5

In regards to oxygen concentration and fires, at what concentrations does what occur?

Answer 5

17% - Flammable liquids cease to burn
12.5% - All flaming combustion ceases
2% - All combustion ceases

Question 6

What effect does an O2 enriched atmosphere have on Upper Flammable limit of flammable gases?

Answer 6

Raises the upper flammable limit of a flammable gas

Question 7

Is N2 – Nitrogen explosive?

Answer 7

No

Question 8

Does Nitrogen support life?

Answer 8

No – will not support life without O2 present

Question 9

What is the general body concentration of CO2 that a person can be exposed to?

Answer 9

1.25% or 12500ppm

Question 10

What are the effects of CO2 on a person at

2%

Answer 10

50% increase resp rate

Question 11

What are the effects of CO2 on a person at

3%

Answer 11

100% increase resp rate

Question 12

What are the effects of CO2 on a person at

10%

Answer 12

Violent panting, fatigue to exertion from breathing effort, collapse within a short period, headache, blood pressure increases

Question 13

Explain why CO2 is refered to as a hot gas?

Answer 13

Due to its low thermal conductivity, heat is not conducted away as rapidly as in normal air so a person feels warm about his lower limbs

Question 14

Give examples of how CO2 is produced and where it is found

Answer 14

Diesel exhaust, Seam Gas, Normal oxidation of coal, timber, Found towards the floor

Question 15

What are the physical /chemical properties of CO2?

Answer 15

Colourless, Slight pungent smell, Soda water taste

Soluble in water

Question 16

What are the physiological effects of CO2

Answer 16

Low concentration – acts as a stimulant on the CNS

High excessive – Depresses the CNS and respiratory system causing unconsciousness, respiratory arrest and death

Question 17

Is CO2 flammable?

Answer 17

no

Question 18

Give the long term exposure limits for the 4 gasses -

CO
H2S
NO2
SO2

Answer 18

CO 30ppm
H2S 10ppm
NO2 3ppm
SO2 2ppm

Question 19

Give a brief description of how the body is poisoned by CO?

Answer 19

CO absorbed into the bloodstream which prevents the blood from absorbing O2 and transporting it to the cells and organs

Question 20

Talk about blood saturation in regards to CO

Answer 20

Because red blood cells take on CO in preference to O2 (300 times) and doesn’t easily release them, the blood becomes more and more saturated

Question 21

Give a brief description of how CO has a cumulative effect on the human body

Answer 21

Person may be exposed for a number of short term exposures, but if not sufficient rest between exposures, the blood will absorb more CO and the person will become more and more susceptible to CO poisoning

Question 22

How is CO produced, give 4 examples ?

Answer 22

Product of incomplete combustion. Always present where:

• U/G Fire
• Diesels exhausts
• Oxidation
• Spontaneous Combustion

Question 23

Is CO explosive, if so at what concentration?

Answer 23

Yes 12.5 -74%

Question 24

What are 6 signs and symptoms of CO poisoning?

Answer 24

Weakness in legs
dizziness
headaches
Nausea
difficulty breathing
heart palpitations

Question 25

What are the physical /chemical properties of CO?

Answer 25

Colourless, Odourless, Tasteless,

Slightly soluble in water