MANAGING BEST PRACTICES: Welding and hex chrome health effects
If an employee is potentially exposed to any amount of hexavalent chromium, then OSHA requires the employer to determine the exposure concentration, through exposure monitoring or objective evidence, and notify the employee of the result. On the surface this requirement appears simple and practical, but meeting the requirement may lead to conflict if care is not exercised. Below are six issues that should be addressed to help manage this risk.
OSHA believes that welders make up almost half of the employees affected by the hexavalent chromium standard. The focus is toward welders who weld or burn on stainless steel and other metals that have chromium added into the product. The intense heat during welding or burning on metal containing chromium may create airborne hexavalent chromium.
Chromium is not intentionally added to mild steel and other metals, such as aluminum, but because the steel- and metal alloy-making process often employs the use of scrap, a trace amount of chromium may occur in metals. Following OSHA’s February 2006 final rule on occupational exposure to hexavalent chromium, some manufacturers began listing in material safety data sheets and product labels trace amounts (e.g. below 0.01%) of chromium in mild steel and other metals. Even if chromium does not appear on an MSDS for mild steel, its presence should now be assumed.
The quantity of chrome in a product is a component of exposure. Another component of exposure is time. Although welding is often performed for short periods - maybe just a fraction of time during a workshift - and shorter time means less exposure to hexavalent chromium, OSHA does not have a cut-off limit for how long an employee may be exposed to hexavalent chromium before an exposure determination is required.
Therefore, issue #1 is whether you should conduct exposure monitoring or develop objective data to demonstrate that employee exposure to hexavalent chromium is below 2.5 ug/m3 as an 8-hour time-weighted average (TWA) during any welding or burning on mild steel or other metals where chromium is not intentionally added but suspected to be present in the product.