Welding Safety FAQs
Fumes & Gases

The most common compounds in arc welding fume mild steel are iron, manganese and silicon although other compounds in the electrode or on the base metal may be in the welding fume.

Fumes from the use of stainless steel and hardfacing products contain chromium or nickel.

Asthma has been reported and some forms of these metals are known or suspected to cause lung cancer in processes other than welding. Therefore, it is recommended that precautions be taken to keep exposures as low as possible.

Manganese overexposure may affect the central nervous system, resulting in poor coordination, difficulty in speaking and tremor of arms or legs. This condition is considered irreversible.

Overexposure to zinc may cause fume fever with symptoms similar to the common flu.

Zinc in welding fume usually comes from welding on galvanized steel.

Each welding power source and container of consumable product has a warning label which contains specific safety instructions regarding the arc welding product you have chosen to use.

An MSDS contains additional information including a summary of the Hazardous Materials used to manufacture the product, a summary of Fire and Explosion Hazard Data, Health Hazard Data and Reactivity Data, and information on the precautions to observe for the Safe Handling and Use of the product.

Inside each Lincoln Electric consumable container. It can also be found on the Lincoln Electric website, on the AWS website and from your supervisor.

1) Keep fumes and gases from your breathing zone and general area 2) Keep your head out of the fumes 3) Use enough ventilation or exhaust at the arc, or both, to keep fumes and gases from your breathing zone and general area.

If special ventilation products are used indoors, use local exhaust. If special ventilation products are used outdoors, a respirator may be required.

Hardfacing and stainless products.

Most of the shielding gases (argon, helium and carbon dioxide) are non-toxic, but they can displace oxygen in your breathing air causing dizziness, unconsciousness and possible death. Carbon monoxide can also be present and may pose a hazard if levels are excessive.

Keep your head out of the fume plume!

Concentration of fumes and gases is greatest in the plume.

Keep fumes and gases from your breathing zone and general area using natural ventilation, mechanical ventilation, fixed or moveable exhaust hoods, or local exhaust at the arc.

It may be necessary to wear an NIOSH approved respirator if adequate ventilation cannot be provided.

OSHA requires that engineering and workplace controls be installed first and if the controls alone do not keep exposures below applicable limits, use respirators.

As a practical rule of thumb for welders, for many mild steel electrodes, if the welder is comfortable and the air is visibly clear, the welder has adequate ventilation.

A welder's exposure can only be determined by having a qualified professional take a sample of the welder's breathing air during the workday.

Measuring a welder's exposure to welding fume is essential if you are welding with stainless, hardfacing or other special ventilation products (see the product label).

If the base metal cannot be cleaned before welding, the composition of the coating should be evaluated.

Stop welding and get some fresh air immediately. If you continue to feel the symptoms, see your doctor. Notify your supervisor and co-workers so the situation can be corrected. Improve ventilation and do not continue welding until the situation has been corrected.

Your work area has adequate ventilation when there is enough ventilation and exhaust to control worker exposure to the hazardous materials in the welding fumes and gases (so the applicable exposure limit for those materials is not exceeded).

The two most common U.S. exposure limits are established by OSHA in the form of permissible exposure limits or PEL and by the ACGIH in the form of Threshold Limit Values or TLV.

Your employer must keep exposures below the PEL.

The PEL and TLV are listed on the first page of the MSDS for compounds in each electrode or flux.

Read the product label, review MSDS for the electrode, determine compounds you may be exposed to. Obtain MSDS for base metal and coatings as well.

Obtain a copy of the supplier's MSDS for the base metal being welded, as this should be reviewed as well.

Natural ventilation is the movement of air through the workplace caused by natural forces. Outside, this is usually the wind. Inside, this may be the flow of air through open windows and doors.

Mechanical ventilation is the movement of air through the workplace caused by an electrical device such as a portable fan or permanently mounted fan in the ceiling or wall.

Local exhaust is a mechanical device used to capture welding fume at or near the arc and remove contaminants from the air.

Workspace volume, configuration, number of welders, welding process/current, consumables used, allowable levels, material welded, natural airflow.

Adjustable "elephant trunk" exhaust systems, fume extraction guns or fixed enclosures, booths with exhaust hoods.

Local exhaust systems are more effective and economical to operate than a general ventilation system, particularly in the winter.

Minimum required air velocity at the welding arc is 100 fpm.

When new ventilation equipment is installed, when the process is modified or when the welder feels uncomfortable. Periodically re-check.

Keep exposure as low as possible and below exposure limit values (PEL and TLV) for materials in the fume using local exhaust.

In confined spaces or in some circumstances, for example outdoors, a respirator may be required if exposure cannot be controlled to the PEL or TLV (see MSDS).

Room contains at least 10,000 cubic feet per welder, ceiling height ≥16 ft, cross ventilation not blocked, welding not done in confined space, and exposure controlled below PEL/TLV.