By Carey Gillam As agrochemical giant  Monsanto Co.  faces a growing wave of U.S. lawsuits over its top-selling  Roundup herbicide line, among its key defense arguments is that the U.S. Environmental Protection Agency (EPA) has long backed the safety of the weed-killing products. And indeed, the EPA has been a stalwart supporter of Monsanto Co.’s … What’s in Roundup? Internal EPA Documents Show Scramble for Data