According to an EPA policy released this month, companies that want the federal government’s stamp of approval for their sustainable products can no longer use such convoluted math.

The EPA’s Safer Choice standard is a voluntary program that allows manufacturers to affix a “Safer Choice” label to their dish soap, laundry detergent and other products. The roughly 1,800 products that have earned that distinction include household cleaners sold in grocery stores and more niche products like industrial carpet stain removers. Until now, the program’s criteria have focused on encouraging brands to reduce their use of toxic chemicals. But the updated standard, released on Aug. 8, strengthens requirements for sustainable packaging as well; plastic packaging must contain at least 15% postconsumer recycled content.