Respiratory Hazards
Objective: To reinforce operational awareness of respiratory hazards and controls associated with welding and hot work.
Combustion creates gases, and molten metal releases fumes, both of which are dangerous when inhaled. Utilizing the hierarchy of controls helps protect workers by minimizing exposure. Engineering controls, good work practices, ventilation, training, and necessary personal protective equipment (PPE) help reduce employees’ respiratory health risks.

Respiratory protection should be worn in conjunction with other required Personal Protective Equipment (PPE) as outlined in a workplace hazard assessment.
Respiratory Hazards
- The following materials are prone to emitting toxic fumes and gases: zinc, chromium, lead, cobalt, cadmium, mercury, and beryllium.
- Confined spaces and insufficiently ventilated areas create oxygen deficiency and toxic atmospheres.
Engineering controls:
- Where possible, remove or substitute the current hazard. Inspect the materials to be welded. Consider:
- Without grinding, is it possible to safely strip off a toxic coating?
- Is there a safer metal that can be used instead?
- Always use air-supplied ventilation when welding in enclosed spaces. Position your work near the duct to ensure toxic fumes and gases are carried away from you.
Administrative Controls:
- Complete all necessary training. Retrain as required by regulations or as needed when workplace conditions change.
- Review all Safety Data Sheets (SDSs) prior to beginning work to understand the hazards of any chemicals or coatings you may be working with.
Respirators:
Before you can use a respirator at work, you must be trained and authorized. This includes completing and passing a medical evaluation and fit test. Respiratory protection must be suitable for the types of workplace hazards you face. See your workplace’s Respiratory Protection Program for more information about facility-specific policies.
- Filter-type respirators use cartridges to filter incoming air and remove contaminants.
- They are required for open-air hot work with metals containing toxic substances such as galvanized steel, zinc, or chromium.
- They will not provide adequate protection in confined spaces lacking sufficient oxygen or ventilation.
- Supplied air respirators (SARs), also known as airline respirators, supply the face mask with clean air from outside of the work are They provide critical life support when working in spaces where flames consume available oxygen.
- They are always required for hot work with beryllium materials or welding in a confined space with inadequate ventilation.
- They may be required when working with cadmium, lead, or mercury-containing materials.