A key federal panel has endorsed the controversial drilling technique known as hydraulic fracturing, or fracking, in shale formations for natural gas. In a new report, the U.S. Department of Energy’s Natural Gas Subcommittee says gas companies should be allowed to drill, provided they disclose chemicals used in the process and face monitoring for contaminants. But critics say the panel has avoided the question of how fracking should be regulated overall and has ignored potential damage to water supplies. In a series of letters, dozens of lawmakers, scientists and environmentalists have criticized the panel, saying six of its seven members have financial ties to the natural gas industry. The panel’s chair, John Deutch, serves on the board of the natural gas company Cheniere Energy. A separate U.S. Environmental Protection Agency assessment of fracking is expected early next year.