The deadline for commentary from the industry public has been moved from July 6, the date outlined in the May 22 ETS, to August 17.

“This action allows commenters sufficient time to submit comments including post-hearing comments,” the agency said, referring to public gatherings that are being held next month in Morgantown, West Virginia (July 10), Lexington, Kentucky (July 12), Denver, Colorado (July 17) and Birmingham, Alabama (July 19).

The May ETS, only the fourth in 30 years, included proposals for the improvement of the design, construction, maintenance and repair of seals and new requisites for the sampling of air behind seals and keeping it at controlled levels, and in it MSHA stated the new deadline will exceed the initial target outlined in the MINER Act of 2006 by seven months.

“Based on MSHA’s accident investigation reports of the Sago and Darby mine explosions, MSHA’s in-mine seal evaluations and review of technical literature, and the National Institute for Occupational Safety and Health's [NIOSH] reports on explosion testing and modelling, we have concluded that immediate action is necessary to provide additional protections for our nation's underground coal miners,” MSHA assistant secretary Richard Stickler said at the time.

The document also outlines a three-tier approach to the prevention and ability to withstand overpressure-loading: “…(1) seals may be constructed at 50psi, but the atmosphere behind them must be monitored and maintained inert; (2) if the atmosphere is not monitored and maintained inert, the seals must be constructed at 120psi; (3) where higher explosion pressures are possible within sealed areas that are not monitored or maintained inert, the seals must be greater than 120psi.”

For the complete ETS or for information on the public hearings and process for submitting input, visit http://www.msha.gov/Seals/SealsSingleSource2007.asp.