Confined Space Training Certificate Ventilation Systems and Equipment 2

Question 1

What is 'dilution ventilation' in the context of confined space operations?

Accepted Answer

The use of fresh air to reduce contaminant concentrations to safe levels

Answer

Ventilation used specifically to remove carbon monoxide from the space

Answer

The addition of water vapour to improve air quality for workers

Answer

A method of extracting all air from the space before entry is permitted

Question 2

For heavier-than-air gases such as hydrogen sulphide (H₂S), where should the exhaust duct inlet be positioned?

Accepted Answer

At the lowest point of the confined space

Answer

At the highest point of the confined space

Answer

In the middle of the confined space at working height

Answer

Outside the confined space near the entry opening

Question 3

What is the term for ventilation that captures contaminants at their source before they disperse into the general atmosphere?

Accepted Answer

Local exhaust ventilation (LEV)

Answer

General dilution ventilation

Answer

Supply (push) ventilation

Answer

Recirculation ventilation

Question 4

How must ventilation equipment be powered when working in a Zone 1 hazardous area inside a confined space?

Accepted Answer

Explosion-protected (ATEX-certified) equipment throughout

Answer

Standard 240V mains power with a residual current device (RCD)

Answer

Battery-powered equipment rated at no more than 24 volts DC

Answer

Air-powered (pneumatic) tools only — all electrical equipment is prohibited

Question 5

What does 'continuous ventilation' mean during confined space operations?

Accepted Answer

Ventilation maintained without interruption throughout the entire period workers are inside

Answer

Ventilation that operates for 30 minutes before entry and then switches off

Answer

A timed cycle of ventilation alternating between supply and exhaust modes

Answer

Ventilation used only during the initial purging phase before workers enter

Question 6

What action must be taken immediately if the mechanical ventilation system fails during confined space work?

Accepted Answer

All workers must immediately evacuate the confined space

Answer

Reduce the number of workers in the space by half and continue the task

Answer

Switch the system to natural ventilation and monitor the atmosphere closely

Answer

Increase the work pace to complete the task before the atmosphere deteriorates

Question 7

Which legislation provides the statutory framework underpinning ventilation requirements for confined spaces in Great Britain?

Accepted Answer

The Confined Spaces Regulations 1997

Answer

The Ventilation at Work Regulations 1992

Answer

The Management of Health and Safety at Work Regulations 1999

Answer

The Workplace (Health, Safety and Welfare) Regulations 1992