The risks associated with welding are well known, and solutions to make this job as safe as possible are easily accessible. But what about employees working next to them? Anyone working in a building where some welding is done should be concerned.

Employees working close to welding operations could breathe toxic fumes and get injured by sparks or molten metal droplets that can fly out. They can also be exposed to electrical hazards, noise, infrared, visible, and ultraviolet radiation.

This blog post will review the risks for people working next to welders. We will also introduce solutions to reduce or even eliminate these risks.

Chemical risks for welders and workers around

As you probably guessed, the first risk we will discuss is breathing toxic fumes. Welding fumes rise and travel in a working environment. Once they cool down, they fall and end up on floors, office furniture, etc. Therefore, they can affect anyone in the building.

Permissible exposure limits for welders and other workers

In the US, OSHA has established a Permissible Exposure Limit, or PEL, for welding fumes of 5 mg/m3. It is the weighted average concentration of the substance over 8 hours inside the worker’s breathing zone. Some substances found in welding fumes must also be kept below their PEL. For example, Hexavalent Chromium has a PEL of 5 μg/m3 as an 8-hour time-weighted average. It will be necessary to analyze the components involved in the welding process to determine which substances must be monitored.

ACGIH recommends a threshold limit value of 0.02 mg/m3 of manganese oxide in the welder’s breathing zone to avoid long-term effects on the nervous system. Read our post about the dangers of manganese fumes to learn more.

Each province or territory in Canada has established its exposure limit, usually between 3 and 10 mg/m3. Some jurisdictions make a distinction between inhalable and respirable particles. In addition, several toxic substances found in welding fumes (such as chromium, zinc, cadmium, lead, ozone, nitrogen oxides, or nickel) also have their concentration limits.

Here are the exposure limits for welding fumes in each Province and Territory in Canada.

  • TWA: Time-Weighted Average over 8 hours
  • STEL: Short-Term Exposure Limit (maximum for 15 minutes, no more than four times per day with at least 60 minutes in between)
  • C: Ceiling (must never be exceeded)
  • (i): Inhalable particles (smaller than 100 µm)
  • (r): Respirable particles (smaller than 4 µm)
  • ALARA: As low as reasonably achievable
BC 10mg/m3(i)*
3 mg/m3(r)*
NB 10mg/m3(i)*
NL 10mg/m3(i)*
3 mg/m3(r)*
QC5mg/m315mg/m3 **25mg/m3
* Based on ACGIH recommendations.
** For 30 minutes during a workday.

If you have any questions about welding fume, do not hesitate to contact us. We will be happy to give you some insight, and we can even visit you for free in the US and Canada.

Henlex Inc.

Health risks associated with breathing welding fumes

According to OSHA, breathing welding fumes could cause the following health effects:

  • eye, nose, and throat irritation
  • joint and muscle pain
  • dizziness and nausea
  • breathing difficulties that could lead to suffocation or asphyxiation
  • metal fume fever
  • lung damage and various types of cancer
  • stomach ulcers
  • kidney damage
  • nervous system damage

The Centers for Disease Control and Prevention (CDC) has also studied the effect of inhaling manganese. Prolonged exposure to manganese fume can cause Parkinson–like symptoms, fertility problems, changes in mood and short-term memory, altered reaction time, and reduced hand-eye coordination.

According to a publication from the International Agency for Research on Cancer (IARC) which has been validated by the Centers for Disease Control and Prevention (CDC), welding fumes are classified as carcinogenic to humans (Group 1).

In Canada, the CNESST also adds these potential health risks to the list:

  • 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

Learn more about the dangers and toxicity of welding fumes.

How to prevent workers from breathing welding fumes

The best way to protect workers around welders is to protect the welders themselves. If the welding fumes concentration is under the PEL in the welder’s breathing zone, it is almost certain that it will be for every worker in the factory.

To achieve this, you must provide welders with welding fume extractors such as MIG welding fume extraction guns, fume extraction arms, or extraction nozzles.

The factory should also be adequately ventilated to maintain good air quality. Welding in a poorly ventilated area is even more dangerous. When air quality standards are not met even with proper extraction and ventilation, employers must provide Personal Protective Equipment such as masks to their workers.

If you are worried about breathing welding fumes and want to know what to do, read our blog post: What to Do if you Inhale Welding Fumes?

Other risks when working close to welders

Sparks and molten metal droplets

While welding, it is expected for sparks and molten metal droplets to fly out. They can burn or injure people, especially if landing in their eyes.

Welders are generally well protected against this risk since they wear a helmet, jacket, and gloves, but people around are not. Therefore, welders should work behind welding screens. Otherwise, you must ensure that the welding area is restricted to people wearing the appropriate personal protective equipment.

Electrical risks

As with any electrical process, electric shock is a risk when welding. Effects can go from pain to burns, muscle contractions, difficulty breathing, and atrial fibrillation.

The best way to protect workers is to restrict the welding workstations to welders only. That way, they will be the only ones to manipulate the equipment and parts to be welded as they are trained to do so safely.

If you are working close to welders, keep your distance and do not touch any equipment or parts they are working on.


Welding, plasma cutting, grinding, hammering, fume extractors, etc. There is a lot of noise around welders. As a result, workers close to them are usually exposed to occupational noise levels requiring corrective actions. Occupational noise can affect workers in numerous ways: stress, fatigue, reduced alertness, irritability, tinnitus, and even hearing loss.

There are three strategies to protect workers:

  • Reduce the noise at the source: turn off any unused equipment (automatic start/stop on fume extractors, for example), ensure that all machines are properly maintained, etc.
  • Isolate loud machines: with silencers, sound absorbing screens, move the equipment to an area with fewer workers, etc.
  • Protect workers: change the work shifts or factory layout to have as few people as possible around loud processes, provide PPE to workers and ensure they are appropriately used, etc.

Infrared, visible, and ultraviolet radiation

Welding arcs and flames emit intense visible, ultraviolet, and infrared radiation. They can cause “arc flashes”, headaches, cataracts, bloodshot, sensitivity to light, and photophobia. In addition, UV radiation will burn unprotected skin, and long-term exposure can cause skin cancer.

With their helmet, jacket, and gloves, welders are usually protected, but it is not always the case with workers around them. Welding operations should be done behind welding screens that will stop radiation. Otherwise, you should ensure that no worker can look at the welding arc by accident or stay close to the welding area without wearing protection for their eyes and skin.

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.