Welding Fume exposure monitoring
April 1, 2008
As of May 30th, 2007, all employers were required to comply with all provisions of OSHA’s hexavalent chromium standard except for engineering controls. To meet these requirements, employers must either perform exposure monitoring or rely on previously documented exposure monitoring. Since exposure monitoring on construction sites is far less prevalent than in general industry, historical data are not likely available in quantity. Fortunately, provisions in the standard allow for industry-wide monitoring.
The OSHA standard allows for the collection of objective data, which is defined as “Information such as air monitoring data from industry-wide surveys; or calculations based on the composition or chemical and physical properties of a substance.” Since I have yet to see manufacturers of materials come forward with such data, industry-wide exposure monitoring would seem to be the best approach. As stated further in the definition, data are required to reflect workplace conditions “closely resembling…those in the employer’s current operations.”
The benefit of an industry-wide study is simple: valid data at a reduced collective cost. According to Christopher J. Cole, CIH, CSP, a welding health and safety coordinator for The Lincoln Electric Company, Cleveland, Ohio, a day of industrial hygiene sampling, including equipment and analytical, can cost around $1,500. Tack on additional samples at $75 per hexavalent chromium analysis, and daily costs per company can average $2,000. The math is easy: 100 individual companies spending $2,000 per day, or exposure monitoring at 20 of those companies that, if gathered correctly, “closely resemble” those in each employer’s operations. The savings are obvious!
Without question, the involvement of a professional with experience in industrial hygiene sampling is necessary. Fortunately, many resources are available:
1. Insurance Providers and State Workers’ Compensation: Insurance companies may be willing to perform monitoring, with the hope that exposures are low enough (or can be lowered) to warrant a reduction in premium to the company, and hopefully reduce claims. This thought carries over into the workers’ compensation realm as well. In Ohio, for instance, the Ohio Bureau of Workers’ Compensation, Division of Safety & Hygiene, has industrial hygienists available for consultation and sampling, a service covered as part of premium payments.
2. OSHA On-Site Consultation Service: Known as the non-enforcement arm of OSHA, this free service will come out in a non-adversarial manner and evaluate worksite conditions for compliance. However, you are required to correct any violations observed.
3. Private Consultants: The American Industrial Hygiene Association’s Web site, www.aiha.org, lists consultants who can assist with exposure monitoring. These fee-based groups have the experience and accreditations to develop a model for success.
4. Trade Associations: Various contractor organizations, such as local affiliates of national organizations like the Mechanical Contractors’ Association of America and the Associated General Contractors of America, may have professionals on staff who can assist.
At the onset of industry-wide monitoring, it is beneficial to conduct a survey to find out what kind of welding and cutting is most prevalent, what materials are used most often, and in what settings the work is performed. Then monitoring can initially focus on the most frequent operations, thus being able to offer early benefit to the largest percentage of the group you represent. While it is likely that shielded metal arc welding (SMAW, or stick) will top the list, your local customers and work settings may alter that perception.
You can also use the survey to identify participants, lay out a schedule based on short- and long-term contractor commitments, and gauge contractor perceptions of field operations (including the use of engineering controls).
If you are going to be doing exposure monitoring, the last thing you want is a documented exposure with no employee health protections in place. As stated in the OSHA standard, the employer shall provide respiratory protection for employees during “periods necessary to install feasible engineering controls and work practice controls” and “during work operations where employees are exposed above the PEL for fewer than 30 days per year, and the employer has elected not to implement engineering and work practice controls to achieve the PEL.”
While you can make a case that you did not expect exposures to be above the PEL for a particular activity, why take a chance? Bulky half-mask respirators with cartridges have given way to tight-fitting dust mask respirators designed for welding operations.
Contracting with a local occupational health group to perform the respirator questionnaire reviews and follow-up physical examinations (if necessary) will streamline the process.
Collection of the air sample is just one piece of a very large puzzle. As stated in the OSHA standard, the use of an air sample as representative is based on this thought of “closely resembling.” A welder working near the ceiling of a mechanical room, 20 feet off the ground in a scissors lift stick welding on carbon steel plate, is different than a welder outside in a trench TIG welding on a stainless steel pipe. Documenting such variables as the type of welding, the material specifications, work habits, engineering controls, location, etc., will allow the data evaluator to better assemble data into common groups that contractors say “closely resemble” their operations.
Location of the sampling cassettes is also critical. While the idea of collecting within the “breathing zone” of the worker has been an established criteria for years, the presence of the welding mask requires a very important variation to the definition: the cassette must be placed within the confines of the welding mask during the welding operation. Details on this requirement can be found in the OSHA Technical Manual, TED 01-00-015 [TED 1-0.15A] and in two separate interpretation letters, which can be accessed from the Standards page at www.osha.gov. Click on Part 1910, then 1910.252, and then on the heading for 1910.252(c), which will direct you to the letters dated 03/22/1995 and 02/03/1999.
Is your data reliable? Is it statistically acceptable to OSHA? Guidance to help answer those questions can be found in two documents:
- Occupational Exposure Sampling Strategy Manual, Publication No. 77-173 (1977) (available at www.cdc.niosh.gov)
- A Strategy for Assessing and Managing Occupational Exposures, Third Edition, Stock Number: AEAK06-327 (2006) (available at www.aiha.org)
Also, you need to have in mind the expected outcome of the various sampling events (your model). The preamble to the regulations, and any monitoring results you have, should be helpful to that end. But be prepared to alter your thinking and your approach to future sampling as your data is compiled.
One important thing to consider: OSHA can issue a citation based on a single air sample for a particular operation, and you can do the same to demonstrate compliance. But statistically, and to avoid a controversy, more is better. Definitely enlist the aid of a professional for this analysis.
SIDEBAR: Other considerations
- Offer a stipend. If you represent numerous companies, offering a stipend will reduce or eliminate contractor out-of-pocket expenses associated with respiratory approvals and the limited downtime in the field, increasing the likelihood of their participation.
- Ask for employee input and feedback. You will need employee buy-in, or you may find yourself dealing with disgruntled participants.
- Collect other analyses at the same time. While other metals cannot be collected on the hexavalent chromium cassette, beryllium, manganese and zinc, for example, can all be collected on a second cassette. It is just a matter of time for performance-based standards for those metals, so why not do it now.