Oxy-Fuel Torch Lighting and Extinguishing Safety

Welding, Cutting & Compressed Gas Safety
English (NZ)

The Problem

Oxy-fuel torches are powerful tools for cutting and heating metal—but if not handled properly, they carry serious risks. Lighting and extinguishing the torch are the most hazardous stages. Mistakes at these points can lead to fires, explosions, or serious injuries. Today, we’ll look at these risks and how to follow the correct safety procedures to keep everyone on site safe.

Identify the Hazards

  • Overpressure: Allowing gas to flow too quickly through the regulators can lead to explosions or equipment failure.

  • Open Flame Ignition: Using unapproved lighters or ignition sources increases the risk of fire.

  • Residual Gas: Failing to purge the system leaves gas in the hoses, which could ignite unexpectedly.
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  • Cylinder Handling: Improper valve operation or unsafe cylinder movement may result in leaks or explosions.

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Safety Practices and Preventative Measures

1. Initial Preparation

  • Turn the regulator screws counter-clockwise to prevent high-pressure gas from flowing suddenly.
  • Close the pre-heat oxygen and acetylene valves on the torch before starting.

2. Opening the Gas Cylinders

  • Stand to the side of the regulators—not in front.
  • Slowly open the oxygen cylinder valve fully.
  • Open the acetylene valve no more than half a turn to maintain control over gas flow.

3. Purging the System

  • Open and close the oxygen torch valve briefly to purge the hose.
  • Repeat with the acetylene valve to clear gas from both lines.

4. Setting the Pressures

  • Adjust oxygen pressure to a maximum of 40 PSI and acetylene to 3–5 PSI (or per manufacturer’s instructions).
  • Once pressures are set, close the valves until lighting.

5. Lighting the Torch

  • Slightly open the acetylene valve on the torch.
  • Use a flint striker or approved ignition source—never use a lighter or open flame.
  • Adjust the acetylene flame to stabilise it, then slowly open the pre-heat oxygen valve to achieve the correct flame.

6. Extinguishing the Torch

  • Close the oxygen valve first, followed by the acetylene valve.
  • Shut off both cylinder valves.
  • Purge residual gas from the system:

    • Open the oxygen valve on the torch to bleed pressure, then close it.
    • Do the same for the acetylene valve.

7. Post-Use Safety

  • Always close cylinder valves when the torch is not in use or cylinders are being moved.

Real-Life Case or Scenario

Where possible, use an actual incident that you have experienced or been involved in.

Recently, a worker didn’t purge residual gas from the hoses after extinguishing the torch. The next time it was used, the remaining gas ignited, causing a flashback. No one was injured, but the equipment was damaged and operations stopped for safety checks. This could have been avoided with proper post-use purging.

Employee Responsibilities

  • Inspect torch equipment and hoses before each use.

  • Follow every step for lighting and extinguishing the torch correctly.

  • Use only approved ignition devices.

  • Purge the system after every use.
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  • Report any unsafe equipment or conditions to your supervisor immediately.

Employer Responsibilities

  • Provide clear training on torch safety and correct handling procedures.

  • Ensure all gas equipment is maintained and regularly inspected.
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  • Replace damaged gear and enforce correct safety practices on site.

Discussion & Questions

  • “What’s the most commonly overlooked step when using an oxy-fuel torch?”
  • “Has anyone witnessed an incident involving incorrect torch use? What did we learn from it?”

Encourage open discussion and sharing of safety ideas or concerns.

Commitment/Action Plan

From today onward, let’s all commit to following every safety step when lighting and shutting down oxy-fuel torches. That includes purging, checking equipment, and using proper ignition tools. These details matter—they prevent injuries and keep everyone safe.

Wrap-Up

Oxy-fuel torches are incredibly effective tools, but they must be handled with care. By sticking to these safety procedures—and following WorkSafe New Zealand’s best practice guidelines—we can eliminate the risks and maintain a safe working environment. Thanks for making safety your priority.

Standards Overview

Under the Health and Safety at Work Act 2015 (HSWA), PCBUs must manage risks associated with hazardous equipment like oxy-fuel torches. This includes:

  • Providing clear training on gas cutting equipment

  • Ensuring workers are competent and confident using torches safely

  • Using approved procedures for equipment setup, operation, and shutdown

  • Inspecting and maintaining cylinders, hoses, regulators, and torches

WorkSafe NZ supports this through guidance on safe gas welding and cutting practices.

Disclaimer

These toolbox talks are provided for informational and educational purposes only and are not a substitute for professional legal, health and safety, or regulatory advice.

The content reflects recognised best practices and general industry standards as at the date of publication. However, it may not be applicable to all workplace environments or specific operational contexts.

It is the responsibility of the Person Conducting a Business or Undertaking (PCBU), as well as officers, workers, and other duty holders under the Health and Safety at Work Act 2015 (HSWA), to ensure compliance with all relevant laws, regulations, and WorkSafe New Zealand guidance.

The authors, presenters, and distributors of this toolbox talk disclaim all liability for any loss, damage, or injury arising from the use or reliance on the information provided. Users should seek advice from a suitably qualified health and safety professional or legal advisor for guidance tailored to their specific circumstances.

Always follow your organisation’s policies, procedures, and safe work practices to manage risks and maintain a safe and healthy workplace.

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Last Updated:
May 12, 2025