CHANTILLY, Va. — The Sheet Metal and Air Conditioning Contractors’ National Association is urging the Occupational Safety and Health Administration to exclude welding from its proposed rule on exposure to hexavalent chromium, commonly called hexchrome, until there is “significant” data justifying additional regulations.

In comments submitted on behalf of its 4,500 member contractors, SMACNA said that the proposed OSHA standard for hexchrome, as it relates to welding, “is not based on good, sound, modern science for realistic economic data concerning the relationship of hexchrome and welding.”

SMACNA noted that most of the studies, exposures and data cited by OSHA relate to industries that manufacture, produce or use hexchrome in forms that are far different from welding operations. SMACNA also said it believes that there is not sufficient research evidence to indicate that welding presents a likelihood of the significant hazard and exposures that may or may not be in other industries that produce and use chromium including hexchrome.

SMACNA also said that the relationship of hexchrome to lung cancer and other adverse health effects in welders has not been adequately proven. The organization believes that OSHA has relied on outdated studies to form its conclusion. SMACNA has suggested that OSHA work on the issue of lung cancer causes among welders, including exposures to asbestos and tobacco smoke in relation to exposure to hexchrome or other chemicals welding produces.