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QUESTION:

Many welding, cutting and allied processes produce potentially harmful fumes and gases. How can my workers avoid overexposure?

ANSWERS:

The first option to avoid overexposure should be to engineer controls to confine, substitute or eliminate air contaminants (i.e. exhaust/ventilation systems). Providing the appropriate respirators is the next option if engineering controls is not feasible.

Employers’ selection process for choosing proper respiratory protection should include:

• Identifying the contaminant and its physical state (solid, liquid or gas);
• Determining the concentration of the contaminant;
• Knowing the amount of time respiratory protection must be worn;
• Health of wearer;
• Location of hazard area, with respect to uncontaminated area (escape route).

OSHA section 1910.134 “requires the employer to develop and implement a written respiratory protection program with required worksite-specific procedures”… “program must be administered by a suitably trained program administrator” and “the employer shall provide the respirators which are applicable and suitable for the purpose intended.” An industrial hygienist for personal monitoring and air sampling may be necessary.

Larry Garner, QSSP, Chief Marketing Officer, MCR Safety

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The inhalation of smoke and fumes as a result of welding, cutting and allied processes can cause health effects ranging from irritation and metal fume fever to chronic health effects, such as metal toxicity or possibly cancer.

The first steps to take in order to avoid the hazard are to know what materials you are working on, read the MSDS, have a health and safety professional evaluate the exposure, and then choose the appropriate level of respiratory protection. Depending upon the severity of the hazard, this may range from an N95 particulate respirator to a self-contained breathing apparatus (SCBA).

Jeffrey Birkner, MS, CIH, Vice President of Technical Services, Moldex-Metric, Inc.

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Welding or cutting in an open air environment poses little threat for the accumulation of gases. However, when welding or cutting in confined spaces the situation is distinctively different.

Since the nature of welding introduces an ignition source into the space and the process can produce toxic gases and deplete oxygen, care should be taken to continuously monitor confined spaces prior to and during entry and occupancy. This is done with a direct reading, calibrated multi-gas monitor equipped with audible and visual warning alarms. At a minimum, the instrument should be able to detect oxygen and combustible gas levels, as well as toxic gases such as carbon monoxide and hydrogen sulfide. Most multi-gas monitors accommodate a variety of sensors that can be easily plugged in and calibrated to be gas specific.

Dave Kuiawa, Sales Manager, North America, Industrial Scientific Corp.

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First, find out the concentrations of the contaminants by doing a site assessment. This involves taking measurements where your workers are welding. Your workers’ compensation insurance company or an industrial hygienist can assist you.

Once you know the concentrations, select the appropriate type mask. Full facepieces will provide a higher level of protection than a half mask; supplied-air more protection than air-purifying respirators.

Finally, know if your worksite conditions change. Have you added a second shift? Are your welders working longer hours to get a big job done? Have you closed your windows for winter? All of these can result in higher concentrations of contaminants and more exposure to your employees. You may need to change the type of respirator your workers wear to one that provides a higher level of protection.

Lynn Feiner, Product Manager, Respiratory Protection, North Safety Products

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OSHA’S welding standard 1910.252 requires that welders use engineering controls as their first line of defense from welding contaminants (e.g., local exhaust hoods). However, in many welding situations the practicality of such controls is limited. Therefore, personal protective equipment (PPE) like respirators are frequently the only feasible alternative.

There are many different types of respirators with varying levels of protection that are appropriate for different welding applications. Respirators, when properly selected and used in conjunction with a complete respiratory protection program, as specified in OSHA 1910.134, can provide an appropriate level of respiratory protection for most welding applications. In fact, some welding respirators can also greatly enhance the productivity and comfort of the welders, by helping to reduce stuffiness and heat inside the welding helmet.

Clifford Frey, CIH, Senior Technical Service Representative, 3M OH&ESD