Key facts
- Welding fume composition changes with the metal, coating, electrode and process.
- Possible effects include irritation, cough, breathing difficulty and metal fume fever.
- Stainless, coated and specialty metals can introduce particularly hazardous constituents.
- Local exhaust should capture fume close to where it is generated.
What is in welding fume?
The plume can contain metals and metal oxides from the workpiece, filler and coatings, plus process gases. Stainless steel, galvanized metal, painted surfaces and confined spaces require special attention.
Because composition varies, “welding fume” is not one substance with one universally suitable filter.
Control the plume
- Substitute lower-hazard processes or consumables where feasible.
- Use local exhaust positioned close enough to capture the plume.
- Keep the welder’s breathing zone out of the fume path.
- Remove hazardous coatings safely and provide general ventilation.
Selecting respiratory protection
Particle filters do not remove gases and vapours. The correct respirator can require particulate filters, chemical cartridges, supplied air or a combination, depending on the assessment. Confined or oxygen-deficient spaces require specialist procedures and cannot be made safe by an ordinary filtering respirator.
Frequently asked questions
Is welding smoke only metal dust?
No. Welding can generate very fine metal-containing particles and gases; exact composition depends on the job.
Does an N95 remove welding gases?
No. N95 filters are for particles and do not remove gases or vapours.
Where should local exhaust be placed?
It should capture the plume close to its source without disrupting the process; placement and airflow should be verified for the specific job.
Sources
This reference was prepared from the following primary public-health and regulatory sources:
- NIOSH Pocket Guide: Welding FumesNational Institute for Occupational Safety and Health
- Welding Operations: Local Exhaust Ventilation SystemsNational Institute for Occupational Safety and Health