Addressing Welding Fume Issues: An 8-Step Approach

Welding fumes present health hazards due to their toxic and carcinogenic nature. It’s crucial to protect welders and their co-workers. With over four decades in the welding industry, we’ve developed a comprehensive 8-step process to mitigate welding fume problems and prevent workers from inhaling harmful particles and gases.

In the upcoming approach, you’ll find that steps 1 through 7 should always be applied (unless unfeasible), while step 8 is a contingency measure if the problem persists. Moreover, the purpose of steps 1 to 4 is to minimize fume production, while steps 5 to 8 focus on safeguarding welders.

Feel free to get in touch if you require assistance or have any inquiries.

1 – Resort to welding only when absolutely necessary.

While this initial step is crucial, it might not always be practical. However, businesses should explore alternatives to manual welding.

Robotic welding has become more economical than ever. Some welding robots prove efficient even for small batch production. This is no longer a luxury reserved for large-scale corporations and is worth considering, especially in the current era when welders are in high demand. Also, managing fumes generated by a welding robot is a lot easier as the primary objective is to protect nearby workers instead of welders close to the welding pool.

Other methods can occasionally substitute welding, such as mechanical fastening (bolts, screws, rivets, etc.), or adhesive bonding (with a range of metal-to-metal adhesives available commercially). However, it’s crucial to ensure that the properties of the alternative bonding method align with your specific needs.

2 – Keep welding tasks separate from other workers

While this measure doesn’t protect welders directly, it does prevent the inhalation of toxic welding fumes by other workers.

Many businesses ensure all welding tasks are conducted in a dedicated building, room, or section. Ideally, this should be a space exclusively used by welders. However, realistically speaking, it’s often possible to minimize the number of workers around welding operations.

If employees work near welders, using welding screens can offer protection from bright arcs, sparks, and harmful ultraviolet radiation. Ceiling-hung welding curtains offer a better solution as they also help contain and extract fumes effectively.

3 – Opt for welding processes that emit fewer fumes

While it’s only one factor in the mix, some welding processes yield fewer fumes than others. That being said, this doesn’t imply they do not need local exhaust ventilation to comply with permissible exposure limits, nor does it mean they’re inherently less toxic.

However, assuming other factors are equal, it’s worth considering which welding and cutting processes to opt for given a choice:

• Less fume: TIG, resistance welding, submerged arc, laser cutting
• More fume: MIG, MAG, plasma cutting
• The most: Stick welding, flux cored, arc gouging

There’s also the option to experiment with power settings to minimize fume emission. An American research study titled Evaluation of operational parameters role on the emission of fumes concluded that: “For reducing exposures to fumes, welders are recommended to use the lowest voltage and amperage and the highest travel speed to the extent that does not compromise in the quality of welds.”

Moreover, a Canadian research institute has provided a comprehensive resource named Influence of Electric Arc Welding Parameters on Fume Concentrations and Their Metal Constituents: State of Knowledge. Here are some key findings from their study:

• “GMAW using the pulsed […] mode generates less manganese and hexavalent chromium fumes than the conventional GMAW process.”
• “An increase in the carbon dioxide fraction in a shielding gas mixture causes a corresponding increase in the quantity of fumes.”
• “An increase in voltage, current strength or electrode diameter also leads to higher fume levels.”
• “The same thing occurs when more flux is used, in the electrode core (FCAW) or coating (SMAW).”
• “For GMAW, pulsed spray transfer is associated with lower fume levels than the short-circuit and axial spray transfer modes.”

Find out more strategies to reduce fume production in our article about this subject.

4 – Opt for materials and consumables that generate less toxic fumes

One fundamental rule to remember is to abstain from welding metal coated with plating, paint, primer, solvent, lubricant, oils, rust inhibitors, or any other type of protective layer. These coatings invariably increase the volume and toxicity of the welding fume, sometimes dramatically.

It’s recommended to eliminate these substances from the welding areas, which in turn can enhance the quality of the weld. During this removal process, it’s vital to adhere to the suitable safety procedures. For more information about the products and safe removal methods, consult your supplier.

While grinding off coatings may seem like an easy solution, it’s crucial to note that grinding dust can be toxic as well and may create a new problem rather than resolving one.

The next thing to do is to minimize the amount of carcinogenic and harmful substances in the materials and consumables used. Here’s a list of metals and gases of particular concern:

• Toxic: lead, manganese, cadmium, ozone
• Carcinogenic: hexavalent chromium, cadmium, beryllium, nickel
• Metal fume fever: zinc, copper, magnesium, aluminum, cadmium, iron oxide, manganese, nickel, selenium, silver, tin

While it’s nearly impossible to completely avoid all these materials, numerous strategies can be employed to lower their concentration.

After following the initial four steps, you should have managed to reduce both the volume and toxicity of the welding fume to the bare minimum. The next task is to ensure workers are protected from inhaling any residual fumes.

5 – Implement welding fume extraction systems

Now it’s time to deploy local exhaust ventilation (or source extraction) to remove the welding fumes. Generally, the closer the extraction point is to the weld pool, the more efficient the system will be, and the better the protection for the welders. There are five primary welding fume extraction technologies:

• Fume extraction MIG guns
• Fume extraction arms
• Fume extraction nozzles
• Fume extraction hoods
• Downdraft tables

The ensuing table suggests the best methods for extracting welding fumes depending on the welding process in use.

Process	MIG gun	Arm	Nozzle	Hood	Table
MIG / GMAW	Best	Yes	Yes	No	No
TIG / GTAW	No	Best	Yes	No	No
Fluxed-Cored / FCAW	Best	Yes	Yes	No	No
Stick / SMAW	No	Best	Yes	No	No
Robotic Welding	Yes	Yes*	No	Best	No

For further guidance on choosing the correct extraction systems and necessary performance specifications, refer to the article about welding fume extractors or MIG welding fume extraction if that’s the process you are using. You can also check our resource helping you choosing between a portable or stationary vacuum unit.

6 – Encourage welders to position themselves to avoid inhaling fumes and gases

Step 6 is straightforward. Welders should leverage environmental factors to steer clear of inhaling welding fumes. For instance, utilizing the wind or air currents can help direct welding fumes away.

As a general practice, welders should avoid positioning their heads directly above the welding pool, as welding fumes naturally rise.

Lastly, welders should never place their heads between the weld pool and the fume extractor. Doing so not only puts them at risk of inhaling fumes but also impedes the extractor’s efficiency. This could lead to the spread of fumes elsewhere within the factory, potentially affecting other workers (this issue is mitigated with fume extraction MIG guns as the fumes are extracted just a few inches from the weld).

7 – Ensure proper ventilation in your factory

Ambient ventilation should complement source extraction, not replace it.

As per OSHA guidelines: “General mechanical ventilation shall be of sufficient capacity and so arranged as to produce the number of air changes necessary to maintain welding fumes and smoke within safe limits.” Typically, an air exchange rate between four and 12 is deemed suitable (this includes air drawn out by fume extractors).

The required rate depends on the volume and toxicity of the fumes generated, and on the effectiveness of the source extraction systems. These systems can significantly lower the required air exchange rate, allowing for a more compact and cost-effective general ventilation system. This, in turn, leads to substantial savings in heating and cooling costs.

The AIHA (American Industrial Hygiene Association) suggests that in a confined space, 20 air changes per hour are considered acceptable practice.

8 – Use personal protective equipment

By this stage, the welding fume issue should be under control, with every workstation meeting the permissible exposure limits. If this isn’t the case, it becomes essential to use personal protective equipment like masks and respirators, each fitted to individual workers.

However, this should be the last line of defense. Health and safety agencies stipulate that all other precautions should be taken before resorting to PPE to tackle welding fume issues. Consequently, masks or respirators should not be a permanent necessity for welding operations; if needed, they should only be used for brief periods.

I will recommend this 3M guide to learn more about respiratory protective equipment for welders if it comes to that.

How much welding fume exposure is harmful?

Health and safety agencies such as OSHA in North America regulate and enforce permissible exposure limits for welding fume, metal fume, and gases. For more information about the maximum allowable concentrations, consider reading the following articles:

• Welding Fume Regulations and Exposure Limits in the US
• Welding Fume Regulations and Exposure Limits in California
• Welding Fume Regulations and Exposure Limits in Canada

These articles also provide recommendations from the American Conference of Governmental Industrial Hygienists (ACGIH). These concentrations are considered safe for welders working no more than 8 hours a day in a typical environment.

In the United States, OSHA and Cal/OSHA enforce a permissible exposure limit for welding fumes of 5 mg/m3 over an 8-hour time-weighted average. In Canada, the health and safety agencies in the Northwest Territories, Nunavut, Quebec, Saskatchewan, and Yukon enforce the same limit. Other provinces and territories adhere to ACGIH recommendations, with the exception of Alberta, which mandates keeping it as low as reasonably achievable.

Several hazardous substances present in welding fumes also have their specific exposure limits, such as chromium, manganese, and others.

Health issues caused by toxic welding fume

According to OSHA, the Centers for Disease Control and Prevention, the International Agency for Research on Cancer, and the CNESST (Canada), breathing welding fumes could cause the following health effects:

• Eye, nose, and throat irritation
• Dizziness and nausea
• Breathing difficulties that could lead to suffocation or asphyxiation
• Metal fume fever
• Lung damage
• Stomach ulcers
• Kidney damage
• Nervous system damage
• Manganism
• Chest pain
• Asthma
• Bleedings
• Dermatitis or eczema
• Kidney disease
• Bone and joint disorders
• Siderosis (iron oxide in lung tissue after inhalation)
• Stannosis (tin oxide in lung tissue after inhalation)
• Anthracosis (poisoning after inhalation of carbon dust)
• Berylliosis (poisoning after inhalation of beryllium dust)
• Accumulation of fluid in the lungs
• Different types of cancer

Any Questions?

Feel free to contact us. We will help you protect your workers and comply with welding fumes standards anywhere in the US and Canada.

1-866-800-8421
info@airgomig.com