The White House today will propose stricter regulations for companies wanting to market new varieties of genetically modified crops. However, environmentalists and consumer groups said the plan could threaten U.S. farm exports overseas and reduce the liability of biotechnology firms. The proposal by the Office of Science and Technology Policy, an advisory group to President Bush, offers guidance on how federal agencies should handle the possibility that unapproved biotech crops might seep into the United States. "We want to make sure the agencies are ahead of the curve should something happen," said a White House official, who requested anonymity. The United States is the world's largest producer of crops that are genetically modified to make them resistant to pests or to withstand herbicides that kill nearby weeds. Critics say not enough research has been done to ensure that genetically modified crops are safe. Under the proposal, Food and Drug Administration would focus its efforts on determining the toxicity and allergenicity of a new biotech crop.:
