Perfumes do, in fact, expire. It all depends on the chemical composition of the scent, but they do break down and oxidize over time. The scent changes, the color of the perfume darkens, and it eventually becomes obvious that the perfume has spoiled. But there\u0026#39;s no way of knowing when a particular scent will die.Unfortunately, sunlight, heat, and humidity will accelerate the deterioration process. So, if you want your perfume to last, keep it in a cool, dark place. Some say the room temperature is even a little warm. Refrigerators are too cold, but some serious perfume enthusiasts and collectors keep their treasures in dedicated mini-fridges set somewhere in between. However, for the non-obsessed perfume owner, a dresser drawer or closet shelf will suffice. Keep the bottle tightly closed to ensure the longest possible life for your perfume. Three Easy Ways to Determine If Your Perfume Is ExpiredHow Does the Fragrance Smell?If your perfume or cologne smells like vinegar or if the concentration of the original scent has changed significantly, it may be expired. It\u0026#39;s also probably expired if the scent is noticeably different from the one you started with.How It Looks.A perfume that is darker in color than what you started with could indicate that it has gone bad. If you started with a clear or translucent gold liquid and now have a more opaque or amber liquid, it may have expired.Expiration Date on the Fragrance PackagingOften, the packaging of your perfume will include an expiration date. This can be either a batch code or a PAO (Period After Opening) number. These are usually found on the bottom of the perfume or printed on the packaging. Many other numbers, such as the catalog number and bar code, are frequently printed on the packaging. To determine if your perfume is expired, you must know which number you are looking at.