In response to requests from the public, on March 26, 2018 the Mine Safety & Health Administration (MSHA) announced that it is reopening the public comment period to the Agency’s request for information (RFI) related to standards concerning the exposure of underground miners to diesel exhaust. Back in June of 2016, MSHA requested further information and data on approaches to control and monitor miners’ exposures to diesel exhaust in light of numerous recent studies linking such exposure to increase risk of developing and dying from lung cancer.  MSHA wanted to reevaluate the standards and exposure limits based on newer diesel powered technology and equipment being used in mining operations.  MSHA specifically wants further input from industry, labor, and other interested parties on ways to enhance control of diesel particulate matter (DPM) and diesel exhaust exposures to improve protections for miners in underground coal and metal/nonmetal mines.

MSHA held four public meetings in 2016 pursuant to this RFI and the comment period was originally scheduled to close on September 6, 2016 but then was extended to November 30, 2016. MSHA and the National Institute for Occupational Safety and Health also convened a Diesel Exhaust Health Effects Partnership (Partnership) and held several meetings with the mining industry, diesel engine manufacturers, academia, and representatives of organized labor to gather more information on the complex questions involved with this issue.  During these meetings, many stakeholders asked to reopen the rulemaking record for comment and MSHA did so through January 9, 2018.

Assistant Secretary of Labor for Mine Safety and Health, David G. Zatezalo, has acknowledged that since the closing of the RFI rulemaking record MSHA has continued to receive stakeholder requests to reopen the record and further extend the comment period on the RFI during the Partnership proceedings. In response, MSHA is reopening the record and extending the comment period to March 26, 2019.  Mr. Zatezalo noted that the reopening of the rulemaking record for public comments will allow all interested parties an additional opportunity to re-evaluate all issues related to miners’ exposure to diesel exhaust and to determine if improvements can be made.