The Food and Drug Administration is seriously considering whether to approve the first genetically engineered animal that people would eat - salmon that can grow at twice the normal rate. The salmon's approval would help open a path for companies and academic scientists developing other genetically engineered animals. The salmon was developed by a company called AquaBounty Technologies and would be raised in fish farms. It is an Atlantic salmon that contains a growth hormone gene from a Chinook salmon as well as a genetic on-switch from the ocean pout, a distant relative of the salmon. Under a policy announced in 2008, the F.D.A. is regulating genetically engineered animals as if they were veterinary drugs and using the rules for those drugs. And applications for approval of new drugs must be kept confidential by the agency. Critics say the drug evaluation process does not allow full assessment of the possible environmental impacts of genetically altered animals and also blocks public input. There is no opportunity for anyone from the outside to see the data or criticize it," said Margaret Mellon, director of the food and [agriculture] program at the Union of Concerned Scientists. When consumer groups were invited to discuss biotechnology policy with top F.D.A. officials last month, Ms. Mellon said she warned the officials that approval of the salmon would generate "a firestorm of negative response."