So apparently, using the toaster or microwave oven is eco-friendlier than stove-top re-heating or cooking. However, for movie night, you might not want to use butter-flavored microwave popcorn. It contains diacetyl, which has been linked to lung disease. It was also named as one of the top 10 most pesticide-contaminated foods in a recent FDA study. Instead, try Eden Organic popcorn or the Whirley-pop popcorn popper.