The Occupational Safety and Health Standards Board of the State of California plans to hold a meeting to collect information regarding a possible new permissible exposure limit (PEL) for n-PB. Specifically, this proposed PEL will be 5 ppm—lower than the ACGIH value of 10 and the EPA recommendation of 25.

“I believe no open-top vapor degreasing machine made today can meet the 5 ppm PEL,” noted John Durkee, PhD, PE, and Metal Finishing's "Cleaning Times" columnist. “And the ability to meet this PEL with the more expensive vacuum-based machines is problematic.”

Durkee admits it may be an overreaction to write that this PEL will ultimately regulate n-PB from being used in solvent cleaning processes. At the same time, promulgation of this PEL is certainly a step toward that end, he notes. (Environmental regulations promulgated in California often later become adopted by the other 49 states as well as foreign countries.)

“The scientific data upon which this PEL will be based upon that collected by the state’s Airborne Contaminants Advisory Committee, which considered substances for development of this proposal and met between May 2001 and January 2004,” he explained. “Between then and now, little sunlight fell on this topic; nor was any newer data evaluated for production of the new PEL. In late January, the proposed regulation was published and a meeting scheduled for its presumed adoption.”

The upcoming meeting on the matter will he held on March 19, 2009, at 10:00 a.m., in the Costa Mesa City Council Chambers, 77 Fair Drive, Costa Mesa, CA, 92626. During this public meeting, the board will make time available to receive comments or proposals from interested persons on any item concerning occupational safety and health.