Lecture 15 (Confined Spaces)

Question 1

Confined Space

Answer 1

An enclosed or partially enclosed area that is big enough for a worker to enter.

Question 2

Three Elements

Answer 2

limited openings for entry and exit
Not designed for continuous worker occupancy
Large enough so employee can enter and work

Question 3

Examples of Confined Spaces

Answer 3

Bins, Bunkers
Tanks, Trenches, Tunnels
Boiler, Furnace

Question 4

Portal Size

Answer 4

Restricted - portal ≤ 24” in least dimension

Unrestricted - portal ≥ 24” in least dimension

Question 5

Horizontal Space Access

Answer 5

Portal located on side of permit space

use of retrieval lines could be difficult

Question 6

Vertical Space Access

Answer 6

Portal located on top of permit space

Rescuers must climb up or down to enter space

Question 7

Natural Ventillation

Answer 7

Deadly gases can be trapped inside
Organic materials can decompose
May not be enough oxygen due to presence of other gases

Question 8

Dangerous Combinations

Answer 8

Worsened conditions due to work activities:
Welding and cutting, use of bonding agents
Use of gas-powered equipment

Question 9

Confined Space Hazards

Answer 9

Safety Hazards
Atmospheric Hazards
Unsafe Actions lack of education and training, lack of enforcement

Question 10

People Needed

Answer 10

Entrant: Read, date and sign report
Person outside the entrance (standby)
Back-up: Near Vicinity

Question 11

Employer’s Responsibilties

Answer 11

Instruct and train workers
Provide PPE and emergency equipment
Appoint a competent tester
Ensure that the worker has read, dated and signed the report

Question 12

Competent Person

Answer 12

Knowledgeable
Be trained in the procedures
Ensure constant communication
Have a standard-level first aid and CPR

Question 13

Employee’s Responsibilities

Answer 13

Competent person follows procedures
Use PPE and emergency equipment
Read and sign the report of the competent tester

Question 14

Written Program

Answer 14

Identify Confined Spaces
Recognize Hazards
Testing and Controls
Emergency Procedures and Rescue
Responsible Parties
Standby Procedures
Training Requirements
Permit Requirements
Pre-entry Requirements and Checks

Question 15

Permit Entry Systems

Answer 15

Written permit signed by entry supervisor

Posted at entry to confined space

Question 16

Permit Entry Requirements

Answer 16

Date, location, and name of confined space.
Purpose of entry and known hazards.
Duration of entry permit time.
Authorized entrants, attendants, supervisors. (and More)

Question 17

Testing Protocol

Answer 17

Before employee enters space, internal atmosphere shall be tested for: 
Evaluation testing
Verification testing
Duration of testing
Testing stratified atmosphere

Question 18

Oxygen

Answer 18

If Less than 19.5% Use appropriate RPE
If more than 23%
No flammable, combustible or reactive material

Question 19

19.5 % Oxygen Deficiency

Answer 19

Minimum acceptable oxygen level.

Question 20

4-6% Oxygen Deficiency

Answer 20

Coma in 40 seconds. Death

Question 21

8-10% Oxygen Deficiency

Answer 21

Mental failure. Fainting. Nausea Unconsciousness. Vomiting.

Question 22

Oxygen Enriched Atmoshperes

Answer 22

Oxygen level above 21%.
Causes flammable and combustible materials to burn violently when ignited.
Never use pure oxygen to ventilate.

Question 23

Flammable Atmosphere

Answer 23

2 Critical Factors:
Oxygen content in the air.
Presence of a flammable gas, or vapour

Question 24

Toxic Atmospheres

Answer 24

Product stored in a confined space:
Gases released when cleaning
Work performed in a confined space:
Painting, scraping, sanding, degreasing

Question 25

Hydrogen Sulfide

Answer 25

Comes from decomposition of materials. Human waste.
Rotten egg odor at low concentrations.
Possibly no warning at high concentrations.

Question 26

Carbon Monxide

Answer 26

Odorless, Colorless Gas
Combustion By-Product.
Quickly collapse at high concentrations.

Question 27

Temperature Extremes

Answer 27

Extremely hot or cold temperatures
Extremely cold liquids
Work processes inside the confined space can increase temperature extremes

Question 28

Engulfment Hazards

Answer 28

Loose, granular materials stored in bins and hoppers - grain, sand, coal, etc
Water or sewage flow

Question 29

Other Hazards

Answer 29

Noise
Slick / Wet Surfaces
Falling Objects
Insects or animals

Question 30

Ventilation

Answer 30

First option to correct problems
Air intake in a safe location to draw fresh air only
Must be aware of hazards you are trying to correct in the confined space

Question 31

Respirators

Answer 31

Air-Purifying Respirators
– Filter dangerous substances from the air
Air-Supplying Respirators
– Deliver a safe supply of breathing air from a tank

Question 32

Isolation

Answer 32

Locking and tagging out electrical sources
Blanking sewer and water flow
Locking and tagging out shutoff valves