Ventilation is used to control overexposures to the fumes and gases during welding and cutting. Adequate ventilation will keep the fumes and gases from the welder’s breathing zone.
NOTE: This does not address ventilation in confined spaces.
Nature of The Hazard - The Fume Plume
The heat or the arc of a welding flame creates fumes and gases, also known as fume plume.
Fumes contain respirable particles.
Gases include the shielding gas and combustion products.
The heat from the arc or flame cause fume plume to rise. These fumes contain hazardous substances and overexposure to them may cause acute or chronic health effects.
Fumes and gases may be produced at toxic levels and they are capable of displacing oxygen in the air resulting in asphyxiation. Overexposure to welding and cutting fumes and gases can cause dizziness, illness, and possible unconsciousness and death.
How to Avoid Welding Hazards - Ventilation
Keep your head out of the fumes. Reposition the work, your head, or both to keep from breathing the fumes.
Ventilation allows control over the fumes and gases that are produced from cutting and welding. Adequate ventilation restricts exposure to dangerous contaminants below acceptable limits.
Have a technically qualified person evaluate exposure to determine if ventilation is adequate. Wear an approved respirator when ventilation is not adequate or practical.
Adequate ventilation is based on:
Natural Ventilation – the movement of air through a workplace by natural forces.
Mechanical Ventilation – is the movement of air through a workplace by a mechanical device such as a fan. Mechanical Ventilation is reliable. It can be more effective than natural ventilation. Local exhaust, local forced air, and general ventilation are examples of mechanical ventilation.
Local exhaust ventilation systems include a capture device, ducting, and a fan. The capture devices remove fumes and gases at their source. Fixed or moveable capture devices are placed near or around the work. They can keep contaminants below allowable limits.
One or more of the following capture devices are recommended:
Local forced air ventilation is a local air moving system. A fan moves fresh air horizontally across the welder’s face. A wall fan is an example of Local Forced Air Ventilation.
When using localized ventilation, remember:
To minimize worker overexposure to fumes and gases: