3.7 Air Contaminants

Stephanie Oostman

Welding, cutting, and grinding operations create an array of respiratory hazards for the welder and other people around the shop or job site. Fumes, dust, gas, smoke, and vapors are just a few. The first step in preventing breathing hazards is proper ventilation. When you are outside on a platform twenty stories up welding on a high rise, the ventilation is going to be different than in a shop or in a confined space such as a ship hull. Each of these situations has a special set of ventilation regulations and parameters. Confined space welding can be particularly dangerous without adequate training, ventilation, and airflow. For example, TIG welding in a confined space may not seem all that dangerous. But consider that while Argon, the purging gas used in GTAW, is inert and not combustible or reactive to other elements in the atmosphere, it is denser than air. If a welder is in a tight space, their air is slowly being displaced with argon. This will eventually cause a suffocation hazard to the welder and workers nearby without proper ventilation regulations, precautions, and inspection.

There are times when additional respiratory protection needs to be taken other than ventilation. In this section, we will review a few articles of PPE that you may find in a welding environment. All respiratory PPE should be certified through NIOSH (National Institution for Occupational Safety and Health) to confirm that it adheres to necessary safety protocols.

Dust Masks

A dusk mask that fits around and under the ears
Figure 3.15. Dusk Mask / Photo Credit: Jernej Furman, CC BY 2.0

In the next section we will discuss respirators, however it’s worth mentioning that there are instances that a simple dust mask may suffice for the job.

OSHA regulation 1910.134 discusses respiratory safety in great detail.

Dust masks do not provide full respiratory protection as they do not create a full seal around the nose and mouth. They only provide a partial seal around the face. A dust mask is called a filtering facepiece. They are mostly designed to cover some or all of the face, with a filtering medium. A filtering facepiece is for filtering out larger material particles like dust, fiberglass, metal chips, and debris. They do not filter out toxic airborne chemicals, or gasses, and are not for hazardous dust particles like chromium.

Respirators

A close-up of a person wearing safety glasses and a respirator
Figure 3.16. A Respirator / Photo Credit: Erik Mclean, Pexels License

Respirators come in all shapes and sizes. There are some things to consider when selecting a respirator for welding. Arguably one of the first things to consider is does it fit, and will it fit under a welding helmet? If the respirator does not create a seal around your nose and mouth or does not fit under the welding helmet, the rest may not matter because you’re not being protected or not wearing it.

N95 class filters are a minimum filter for welding when it comes to filtering out larger particles, oil and non-oil lubricates in the air. The filters on a respirator have a service life. Meaning a specified time that the filters provide safe and adequate function. It is possible to run through filters prior to that time if you are working in a particularly dusty or dirty environment with a lot of particles in the air. N95 requires a clean-shaven face, fit testing by an authorized person, and record keeping. If the company requires N95 they must pay for it.

PAPRS

PAPRS is short for Powered Air Purifying Respirator. These are battery-powered full or partial-face respirators that filter air through a canister or cartridge. This unit uses a blower to pass air through a HEPA-grade filter which is then passed to a mouthpiece or sealed face mask. PAPRS do not require fit testing for a proper seal and may be a choice of respiratory PPE for those with facial hair that otherwise may not allow them to pass a fit test. When outfitted appropriately PAPRS may provide protection to the wearer from vapors, dust, debris, smoke, and gasses.

Supplied Air

An underwater welder works in PPE especially designed for their environment and task.
Figure 3.17. Underwater Welder / Photo Credit: Israeli Navy, CC BY-SA 3.0

Supplied air respirators (sar) provide a user a fresh air source via a hose connected to compressed air. These respirators don’t just filter air coming in, they supply a whole fresh air source. This is ideal for individuals working in a hazardous or toxic air environment for long periods of time. The air source on these products is stationary whereas in other PPE products, the air supply is attached via a canister the user carries or is a filter attached to the facemask. An example here would be a diver that has a fresh air feed to the surface vs an air tank on their back.

Attributions

  1. Figure 3.15: Face mask or dust mask or filtering facepiece respirator – breathing protection against air pollution or flu or virus outbreak by Jernej Furman is released under CC BY 2.0
  2. Figure 3.16: image released under the Pexels License
  3. Figure 3.17: Underwater oxy-arc cutting by Israeli Navy is released under CC BY-SA 3.0
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Introduction to Welding Copyright © by Washington State Board for Community and Technical Colleges is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.