The Agriculture Department has exempted a genetically engineered grass from federal regulation, a decision that some critics say could portend a loosening in oversight of biotech crops. The department said that an herbicide-tolerant Kentucky bluegrass being developed by Scotts Miracle-Gro was not subject to federal regulation because its creation did not entail use of any plant pests. The genetically engineered bluegrass contains a gene that allows it to tolerate the widely used herbicide Roundup, also known as glyphosate. That allows the chemical to be sprayed to kill weeds without harming the grass. The decision shocked some critics of biotechnology crops. It's a blatant end-run around regulatory oversight," said George Kimbrell, senior lawyer at the Center for Food Safety, a Washington advocacy group. Margaret Mellon, director of the food and environment program at the Union of Concerned Scientists, said other companies might follow the same strategy, putting the Agriculture Department "out of the game of regulation." The critics say there have been other signs that the Agriculture Department has been looking to weaken regulation, like a proposed pilot project that would let companies provide more input into the environmental assessments of their crops.