CCN1 Gas Emergency Procedures 2 — Questions and Answers
Question 1: What is a 'gas incident' that a Gas Safe engineer is required to report to the HSE?
- Any death, injury, or near miss attributable to a gas fitting or appliance, including CO poisoning incidents (Correct answer)
- Only incidents resulting in death
- Only incidents on commercial premises
- Incidents only if caused by the engineer's own work
Correct answer: Any death, injury, or near miss attributable to a gas fitting or appliance, including CO poisoning incidents
Gas Safe engineers are required to report to the HSE any incident involving death, injury, or dangerous occurrence attributable to a gas fitting or appliance, including CO poisoning. This is required under RIDDOR (Reporting of Injuries, Diseases and Dangerous Occurrences Regulations).
Question 2: What is the significance of CO (carbon monoxide) in the context of gas emergencies?
- CO is colourless and odourless, highly toxic even in small concentrations, and can rapidly cause loss of consciousness and death (Correct answer)
- CO has a distinctive smell that warns occupants before dangerous levels are reached
- CO is only dangerous outdoors
- CO is only produced by malfunctioning appliances — a serviced appliance cannot produce CO
Correct answer: CO is colourless and odourless, highly toxic even in small concentrations, and can rapidly cause loss of consciousness and death
CO is colourless and odourless, making it undetectable without a CO alarm. It combines with haemoglobin in the blood far more readily than oxygen, rapidly causing incapacitation and death even at relatively low concentrations.
Question 3: What are the recommended actions for a Gas Safe engineer if they detect high CO levels in a property?
- Evacuate the occupants immediately, ventilate, call 999 if anyone is affected, and do not restore gas until the source is identified and repaired (Correct answer)
- Complete the work and advise the occupant to open windows
- Test the CO level with a monitor and leave if it is below 100 ppm
- Only act if the CO level exceeds 1,000 ppm
Correct answer: Evacuate the occupants immediately, ventilate, call 999 if anyone is affected, and do not restore gas until the source is identified and repaired
High CO levels require immediate evacuation of all occupants, ventilation of the property, calling 999 if anyone shows symptoms (headache, nausea, dizziness), and not restoring gas until the source is identified and remedied.
Question 4: What is the purpose of a CO alarm in a domestic property?
- To provide early warning of CO accumulation before dangerous concentrations are reached, allowing occupants to evacuate (Correct answer)
- To automatically shut off gas appliances when CO is detected
- To measure the efficiency of gas appliances for service purposes
- CO alarms are only required in commercial properties
Correct answer: To provide early warning of CO accumulation before dangerous concentrations are reached, allowing occupants to evacuate
CO alarms provide an audible warning when CO concentrations rise, giving occupants time to evacuate before reaching dangerous levels. They are the only way to detect CO, which has no smell or colour.
Question 5: If a Gas Safe engineer arrives at a property and finds a CO alarm sounding, what is the correct immediate action?
- Evacuate occupants, ventilate the property, do not operate any electrical switches, and call 999 if anyone shows symptoms (Correct answer)
- Turn off the CO alarm and investigate the appliance
- Check the appliance before evacuating to confirm CO is actually present
- Assume the alarm is faulty and reset it
Correct answer: Evacuate occupants, ventilate the property, do not operate any electrical switches, and call 999 if anyone shows symptoms
A sounding CO alarm must be treated as a real emergency. Evacuate all occupants, ventilate, avoid electrical switches, and call 999 if anyone is symptomatic. Do not waste time checking whether the alarm is genuine before evacuating.
Question 6: What special precaution must be taken before re-entering a property after a gas escape has been reported?
- The gas network operator's engineer must have confirmed it is safe to re-enter and the gas supply has been isolated or the fault repaired (Correct answer)
- Re-entry is permitted once 30 minutes have elapsed after the escape
- Re-entry is the occupant's own decision
- Only the police can authorise re-entry after a gas escape
Correct answer: The gas network operator's engineer must have confirmed it is safe to re-enter and the gas supply has been isolated or the fault repaired
A property must not be re-entered after a gas escape until the gas network operator's engineer (or Gas Safe engineer if appropriate) has confirmed the gas supply is isolated or the fault repaired and the property is safe.
CCN1 Gas Emergency Procedures 2
What is a 'gas incident' that a Gas Safe engineer is required to report to the HSE?