Specialist Trade Hazards Flashcards

A gas engineer smells gas on arriving at a job. What is the first action?

Answer: Do not operate any switches — ventilate the area and call the National Gas Emergency line (0800 111 999)

On smelling gas, no electrical switches should be operated as a spark could ignite the gas. The area must be ventilated immediately by opening doors and windows, then the National Gas Emergency Service called on 0800 111 999.

What is the main hazard of using an oxy-acetylene torch in a confined or poorly ventilated space?

Answer: Oxygen depletion and build-up of toxic combustion products leading to asphyxiation and fire risk

Oxy-acetylene equipment consumes oxygen and produces carbon monoxide and other combustion products. In confined or poorly ventilated spaces, this can cause oxygen depletion and toxic gas accumulation leading to asphyxiation and explosion risk.

A specialist electrical contractor is working on a live panel. What regulation governs this work?

Answer: Electricity at Work Regulations 1989 — live working is only permitted when dead working is not reasonably practicable

The Electricity at Work Regulations 1989 require that electrical systems be made dead before work begins unless it is not reasonably practicable to do so. Live working requires formal risk assessment, appropriate PPE, and trained personnel.

What hazard is associated with polyvinyl chloride (PVC) pipe when it is cut or welded?

Answer: Release of toxic chlorine-containing fumes requiring local exhaust ventilation

Cutting, welding, or heating PVC releases hydrogen chloride and other toxic fumes. Local exhaust ventilation and appropriate respiratory protection are required when working with PVC in enclosed areas.

What is the greatest risk when a plumber uses a blowtorch in a wall cavity?

Answer: Setting fire to hidden timber or insulation causing a concealed fire

Blowtorch flames in wall cavities can ignite hidden timber studwork, insulation, or other combustibles, creating concealed fires that spread unseen before being detected. Fire watch procedures and fire-resistant materials should be used.

When must a specialist contractor check for asbestos before starting work?

Answer: Before any work that may disturb building materials in structures built before 2000

Any work that may disturb building materials in structures built before 2000 requires checking the asbestos register or carrying out a survey. Asbestos was used in many building products and disturbing it without precautions is extremely dangerous.