Contaminated or flammable atmosphere toolbox talk

What it is

Air in the work area that may hold harmful contaminants or flammable gases, vapours or dusts.

Controls to check, most effective first

1. Do the work from outside the space, or remove contaminants by cleaning or purging before entry, where possible.
2. Isolate pipes and services that could let gases, vapours or liquids into the work area before anyone enters.
3. Ventilate with forced air, using intrinsically safe equipment where flammable gas may be present, and never ventilate with pure oxygen.
4. Test the atmosphere for oxygen, flammable gases and toxic contaminants with a calibrated gas detector before entry and during work.
5. Control entry with a permit, a standby person and a rescue plan that has been tested.
6. Provide supplied-air respiratory equipment where a safe atmosphere cannot be maintained.

Where it comes up on the job

Work steps from SafetyDocs templates that deal with contaminated or flammable atmosphere:

• Confined spacesAsphyxiationFrom Hoarder Cleaning Plan
• Fixing pipework, tanksControl trench collapse, hazardous atmosphere, falls, cuts, sewer biohazards, fumes and laser risks when fixing pipework.From Plumbing Drainage
• Vent/degas tankVent the tank safely to prevent explosions and asphyxiation.From Fuel Tank Maintenance Bulk-Manned Entry
• Working with powered & non-powered toolsPrevent electrocution, injury, fire and asphyxiation.From Road Safety Barrier Installation

Questions for the crew

1. Where could contaminated or flammable atmosphere come up on this job today?
2. The most effective control is: “Do the work from outside the space, or remove contaminants by cleaning or purging before entry, where possible”. Can we do that here? If not, why not?
3. Which controls for contaminated or flammable atmosphere are missing or not working on this site?
4. When would you stop work because of contaminated or flammable atmosphere, and who would you tell?
5. How do we report a hazard, a near miss or an incident on this job?