By 1934 the U.S. Public Health Service estimated that 80% of American felt makers had mercurial tremors. Nevertheless, trade union campaigns (led by the United States Hat Finishers Association, originally formed in 1854) never addressed the issue and, unlike in France, no relevant legislation was ever adopted in the United States. Instead, it seems to have been the need for mercury in the war effort that eventually brought to an end the use of mercuric nitrate in U.S. hatmaking; in a meeting convened by the U.S. Public Health Service in 1941, the manufacturers voluntarily agreed to adopt a readily available alternative process using hydrogen peroxide.[1]