At its fifth and final meeting on Sept. 17-19 in Washington, D.C., the technical study panel established by the MINER Act to study the issue of belt air ventilation unanimously recommended its use as long as MSHA district managers are required to take special care to evaluate whether it can be used in a manner that is safe for all miners involved.
This recommendation echoes the practice that MSHA had employed before revising 30 CFR to allow belt air in all underground coal mines provided certain precautions were present. The practice previously required mine owners to go through a Petition for Modification (PFM) process to receive approval on a case-by-case basis. When granted permission to do so, several safety precautions were usually stipulated, such as a fire monitoring systems.
Belt air refers to the practice of using air from the belt entry to ventilate the work areas. PFMs were most often asked for when it was believed that drilling additional ventilation tunnels in a certain mine presented structural hazards.
Industry and workers have long been divided on this issue. Previous technical panels have studied the issue for decades, sometimes in favor and sometimes against its use.
Many believe that air passing over the conveyor belt might entrain respirable dust, increasing miner exposure to dust at the face. Another major concern has been fire in the belt entry. Such fires can occur by the very nature of conveyor belt systems and because no additional ventilation tunnel is created to be used to exit, if a belt fire occurred, miners would often become engulfed in smoke and toxic gases in seconds and find it impossible to evacuate.
Many argue that the use of several safety precautions, such as a fire monitoring systems, negate this hazard or at the very least presents an equivalent amount of safety as additions ventilation tunnels.
In related news, the National Mining Association filed comments this week with MSHA regarding the agency's Emergency Temporary Standard covering the sealing of abandoned areas in underground coal mines. The comments included: suggested revisions to the regulatory language with an accompanying explanation for the revisions; responses to the questions and requests for information contained in the preamble to the ETS; three technical evaluations of NIOSH's final report on "Explosion Pressure Design Criteria for New Seals in U.S. Coal Mines"; and a document titled "Excerpts Taken from This Report on the 'Mitchell-Barrett' Solid-Concrete-Block Seal," which contains the results for tests conducted by NIOSH on the Mitchell-Barrett solid concrete block seal.
Copies of the submittal, along with relevant attachments, can be viewed at www.nma.org/tmp/091807_ets_seals.asp.