Currently, the U.S. Food and Drug Administration, with a few exceptions, has no requirements for cosmetics to be labeled with either a manufacturing date, “best by” use date or PAO. Manufacturers are held responsible for making sure their products are safe.
More recently, since the early 2000s, the Period After Opening (PAO) indicator became a requirement for most cosmetic products in the EU.1 The exceptions were single-use packaging, products whose packaging prevented contamination during use, or formulations that did not support microbial growth.
