MSHA continues to request information from underground stakeholders concerning the exposure of underground miners to diesel exhaust. The original notice and request for information was published on June 8, 2016. The motivation behind MSHA’s request for information and data stems from a joint study conducted by the National Cancer Institute and the National Institute for Occupational Safety and Health in March 2012. The study examined 12, 315 miners in 8 metal/nonmetal facilities for the purpose of determining whether breathing diesel exhaust could lead to lung cancer and/or other respiratory health issues. The study determined that diesel exposure increased miners’ risk of death from lunch cancer, and as a result, MSHA issued a request from stakeholders in an effort to review the original underground diesel particulate matter standard passed in 2001, and the Metal/Non-Metal diesel particulate matter standard passed in 2006. This is an initiative put forth by the previous MSHA administration. However, the new administration has not indicated that it would withdraw the RFI, or put a freeze on the comment period.

On March 26, 2018, MSHA extended the comment period to March 26, 2019. MSHA received numerous requests from stakeholders to extend the comment period following MSHA open hearings, as well as a meeting of the partnership formed by MSHA NIOSH which included members of the mining industry, diesel engine manufacturers, academia, and representatives of organized labor. Following the Workplace Examination Rule for Metal/Non-Metal mines goes into effect, the DPM rule evaluation will be the most significant rulemaking agenda topic on the MSHA schedule. The effective date for the workplace examination rule is June 2, 2018, and so MSHA is expected to turn its focus to the DPM rule evaluation early summer, 2018.