Respiratory Health 101: What You Need to Know about Welding PPE
When welders utilize the correct respirators work can be done safely and efficiently.
Welding, joining together metal parts by heating the surfaces to the point of melting, inherently comes with some occupational hazards. They vary by application; however, sparks, spatter, particulate fumes and arc rays are some of the hazards that may be present. To protect from these hazards, personal protective equipment (PPE) is needed. The common or foundational types of PPE for welding are:
- Safety Glasses
- Welding Helmet
- FR Welding Jacket
- Leather Welding Gloves
For some welding applications, additional PPE, including respiratory protection, may be required if exposure to welding fume constituents exceeds defined limits, such as OHSA’s Permissible Exposure Limits (PELs), which we will expand on later.
Ultimately, welding PPE can be thought of as a system or circuit in which multiple items may be used together to provide adequate protection from the hazards the operator may be exposed to.
Welding Fume & Potential Respiratory Hazard Considerations
Fume is created when metal or other solids vaporize and molecules condense in cool air. Fumes created during mild steel welding include complex metallic oxides of iron and manganese. Welding on galvanized steel may produce a condition known as “metal fume fever,” which presents with flu-like symptoms such as headaches, chest pain, nausea, joint pain, fever and chills.
Weld and filler metal coatings can contain such substances as lead, chromium or zinc. It’s best to remove coatings before welding whenever possible. Welding with stainless steel and hard-facing consumables may require additional ventilation and other protective measures to eliminate or minimize exposures.
Welding in confined spaces can exacerbate any of these potential hazards. When possible, welding should be done in open, well-ventilated areas. Respiratory protection is essential when exposure levels can or do exceed applicable exposure limits.
Understanding Respiratory PPE
As mentioned above, welders must use respiratory protection if exposures to various constituents of welding fume exceed the limits set forth by OSHA PEL or the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLV). Following the OHSA PEL is required by law within the US but Lincoln Electric recommends welders comply with whichever threshold is lower.
OSHA and the National Institute of Occupational Safety and Health (NIOSH) recognize two concepts for the proper selection of respiratory protection: assigned protection factors (APF) and maximum use concentration (MUC).
APFs are the workplace level of respiratory protection provided by a respirator when an employee implements a “continuing, effective respiratory protection program.” Maximum use concentrations (MCUs) represent a hazardous substance’s “maximum atmospheric concentration” from which respirators can protect employees. It’s determined by the respirator’s APF and the substance’s applicable airborne exposure limits. It also takes PELs in the workspace into account.
A respirator’s maximum protection is calculated by the following formula:
APF x PEL (or applicable limit) = MUC.
The proper level of protection is critical when it comes to choosing the right type of respiratory protection. Two popular types that might be selected when they meet the necessary selection criteria include:
- Powered Air Purifying Respirators (PAPR)
- Reusable Half-Mask Welding Respirators
Powered Air Purifying Respirators (PAPR)
Loose-fitting, positive-pressure powered air-purifying respirators deliver filtered ambient shop air to the operator. These NIOSH 42 CFR Part 84-approved respirators are a comprehensive system that can include an air-purifying blower, high efficiency particulate arrestance (HEPA) filters, custom welding helmet and more.1
These systems feature a HEPA filter that provides rated protection against respirable dust and metal fume particles, including hexavalent chromium, oxides of manganese andiron, zinc oxide, aluminum, nickel, beryllium, cadmium, and lead fumes. They filter out 99.97 percent of this particulate at 0.3 microns. Additionally, most PAPRs also feature a spark screen that protects the filter from fire while filtering large particulate, and a pre-filter that traps medium sized particulate while increasing HEPA filter life. PAPRs for welding commonly have an APF of 25.
Reusable Half Mask Respirators
One of the most common, low cost and readily available types of personal respiratory equipment is half mask respirators, which historically were not widely used within the welding industry. Why? Simply put, most half mask respirators weren’t compatible with other welding PPE and/or were uncomfortable. Luckily, modern R&D advances in this respiratory PPE category have improved both compatibility and comfort, making these respirators more widely used for metal fabrication.
Reusable half-mask respirators may feature various classifications of filters, including N99, P99, N100 or P100 NIOSH-rated filters. The most common filter in half-mask respirators used for welding is a P100 rated filter, which delivers 99.97 percent efficiency in filtering non-oil and oil-based particulates and aerosols on the shop floor. Half-mask respirators with these filters offer an APF of 10.
When selecting personal respiratory equipment, first and foremost, you must select equipment that provides the proper level of protection (including APF and MUC) for your specific application. After safety needs are met, then other product specific criteria should be evaluated.
These product specific elements include but aren’t limited to:
- Product Cost
- Filter Life
- Fit Test Requirements
- Welding-Specific Features
While cost, filter life and comfort are self-explanatory, fit test requirements and welding specific features are a regulatory workplace requirement.
Fit test requirements are specific to the type, make and model of personal respiratory equipment. These fit tests go beyond mere comfort assessments, and help ensure a tight seal on the operator’s face. For half-mask style products, each operator must take and pass a fit test before using one. This is often done as part of a comprehensive workplace respiratory protection program, and should be done by trained personnel. Additionally, the operator will need to check the seal each time the half-mask respirator is used. Conversely, loose fitting, Powered Air Purifying Respirators do not require a fit test before use and provide a more consistent, flexible seal.
Once safety needs are met, welding-specific features are often what drives the final product selection and purchase decision. For PAPRs, optic quality is often a critical feature. The auto-darkening lens for welding will have an optical clarity rating per EN 379 standards. This standard measures the lens’ blurriness, distortion, shade consistency and shade performance at an angle. The highest or best optical clarity rating is 1/1/1/1 while the worst is 3/3/3/3. All Lincoln Electric PAPRs feature an optical clarity rating of 1/1/1/1. For Half Mask respirators, the physical size of the product and the filter design are critical. The physical size must fit underneath your operator’s welding helmet. While simple in theory, many products will not pass this step of the evaluation. Once you find products that will fit, then you should consider the filter design. We recommend filters that are enclosed with a protective nylon housing, which will shield the filter media from the spatter and sparks that may be generated by metal fabrication.
Respiratory protection is a critical part of keeping the welder safe from potential overexposures when conducting welding, or its allied processes. The correct type or respirator with the right capabilities and level of protection must be selected for the specific type of work that is being performed. Respiratory protection must be worn only by those adequately trained in their care, use and limitations, and assigned to personnel under the processes outline in a compliant respiratory protection program. Certain types of respiratory protection such as a PAPR can provide flexibility, comfort and ease of use; while others such as a low profile 1/2 face negative pressure respirator can fit easily under existing welding headgear.
When welders utilize the correct type of respirator with the appropriate level of protection, the work can be done safely and efficiently—and with greater comfort. After all, protecting the health and well-being of workers is priority one.
This article originally appeared in the May 2022 issue of Occupational Health & Safety.