Back in 2008, European Food Safety Authority began pressing the chemical industry to provide safety information on a substance called diphenylamine, or DPA. Widely applied to apples after harvest, DPA prevents “storage scald”—brown spots that “becomes a concern when fruit is stored for several months,” according to Washington State University, reporting from the heartland of industrial-scale apple production.
DPA isn’t believed to be harmful on its own. But it has the potential to break down into a family of carcinogens called nitrosamines—not something you want to find on your daily apple. And that’s why European food safety regulators wanted more information on it. The industry came back with just “one study that detected three unknown chemicals on DPA-treated apples, but it could not determine if any of these chemicals, apparently formed when the DPA broke down, were nitrosamines,” Environmental Working Group shows in an important new report. (The EFSA was concerned that DPA could decay into nitrosamines under contact with nitrogen, a ubiquitous element, EWG notes.) Unsatisfied with the response, the EFSA banned use of DPA on apples in 2012. And in March, the agency then slashed the tolerable level of DPA on imported apples to 0.1 parts per million, EWG reports.