ACS Emergency Procedures 1 — Questions and Answers
Question 1: What is the first action to take if a gas escape is suspected in a property?
- Open the gas meter box and check for a leak
- Do not operate any electrical switches; open windows and doors; turn off the gas at the emergency control valve; call 0800 111 999 (Correct answer)
- Call the local gas board and wait for their arrival
- Light a match to check whether gas is present
Correct answer: Do not operate any electrical switches; open windows and doors; turn off the gas at the emergency control valve; call 0800 111 999
On suspecting a gas escape: do not operate any electrical switches (prevent ignition sparks), ventilate immediately, turn off the gas at the emergency control valve, leave the building, and call the National Gas Emergency Service on 0800 111 999.
Question 2: What is the emergency gas service telephone number in Great Britain?
- 999
- 0800 111 999 (Correct answer)
- 0300 123 1234
- 112
Correct answer: 0800 111 999
The National Gas Emergency Service (operated by Cadent, SGN, Northern Gas Networks, and Wales & West Utilities) is contactable 24 hours a day on 0800 111 999.
Question 3: If CO is suspected in a building, what immediate actions should be taken?
- Open one window and investigate the source yourself
- Evacuate all occupants immediately, call 999, do not re-enter, seek medical attention for anyone showing symptoms, and call the gas emergency service (Correct answer)
- Turn off all gas appliances and remain in the building
- Call the landlord or building manager first
Correct answer: Evacuate all occupants immediately, call 999, do not re-enter, seek medical attention for anyone showing symptoms, and call the gas emergency service
CO can incapacitate rapidly — immediate full evacuation, fresh air, medical assessment of anyone with symptoms (headache, dizziness, nausea), and calling emergency services are the priority actions.
Question 4: When a gas engineer attends a property following a CO alarm activation, what is their first priority?
- Identify the source of CO using a flue gas analyser
- Ensure all occupants are safe and out of the building before entering to investigate, carrying a CO monitor personally (Correct answer)
- Silence the CO alarm before investigating
- Check the boiler service record before entering
Correct answer: Ensure all occupants are safe and out of the building before entering to investigate, carrying a CO monitor personally
The engineer's personal safety and occupant welfare come first — the engineer must wear or carry a CO detector, confirm occupants are out, and only then begin to investigate the source of CO.
Question 5: What procedure should a gas engineer follow if they discover an Immediately Dangerous (ID) gas situation at a customer's property?
- Repair the fault immediately without informing the customer
- Inform the customer, obtain consent to make safe (disconnect), issue a Gas Safe warning notice, and document the situation (Correct answer)
- Leave the property without taking action
- Call the HSE before taking any action on site
Correct answer: Inform the customer, obtain consent to make safe (disconnect), issue a Gas Safe warning notice, and document the situation
An ID situation requires the engineer to inform the customer, obtain consent to isolate, make the installation safe, issue a written warning notice, and document all actions for the record.
Question 6: What should a gas engineer do if they smell gas while working inside a property?
- Continue working with increased caution and ventilate by opening a nearby window
- Stop work immediately, do not operate any electrical equipment, evacuate the building, isolate the gas supply externally if safe, and call 0800 111 999 (Correct answer)
- Test for gas using a lighter to check the concentration
- Call the customer's landlord before taking any safety action
Correct answer: Stop work immediately, do not operate any electrical equipment, evacuate the building, isolate the gas supply externally if safe, and call 0800 111 999
Any suspected gas escape requires immediate cessation of work, no electrical switching, evacuation, external isolation if safe, and calling the gas emergency service — personal safety and prevention of ignition are paramount.
ACS Emergency Procedures 1
What is the first action to take if a gas escape is suspected in a property?