Expiration dates are something we have faced our entire lives, whether it is the milk that just went bad two days ago or the meats that is appearing to become a science experiment. Now days industries are adding "best by" dates to consumables that may suffer over time. The latest concern surrounds the vape market, which tries to remain friendly with consumers and federal agencies.
The Food and Drug Administration do not require food companies to place "expired by" or "best before" dates on food items. This information is left up entirely to the manufacturer. The FDA laws that foods in the country must be fit for consumption and therefore a "best by" date does not relieve the company from that obligation. These dates have been acknowledged as just suggestions or guidelines. The FDA's Center for Tobacco Products are the regulators when it comes to e-cigarettes and vaping products and has strict regulations but does not require expiration dates on all e-liquid labels, for now.
American consumers don't really know for sure how long their e-liquids can last. Officials have estimated that properly stored bottles should be fine for at least two years. To ensure longevity, store e-juices in glass bottles and keep in a cool, dark place, possibly extending its life longer than bottles sitting next to an open window. Storing it properly may even allow you to exceed any expiration dates posted on the package. Expiration dates are more about freshness rather than positive indicators of spoiling. However, this doesn't apply to all liquids. Some vape juices that are all-natural made with a few ingredients, might not keep as well as those made with artificial flavors. Even a bargain-brand e-liquid hidden in the basement might be able to outlast any juice you have on your shelves, but could end up tasting harsh and odd.
The shelf-life of most e-liquids is based on several things. First, the quality of PG, VG, nicotine and the flavorings. Second, the mixing rations and the conditions under which the product is being handled. Last, quality is a key part. If you buy the cheap e-liquids, do be surprised to see the nicotine oxidizing quicker than the expensive e-liquid products. Also, when not using the liquids keep the product in a dark room. Leaving them in the open in direct sunlight or in a room with varying temperatures, high humidity will cause the nicotine to become darker and bitter.
Flavorings also determine the shelf-life of your e-liquids. Ingredients such as vanilla lack the preservatives of other chemical-based juices, decreasing shelf life. Other natural flavorings may even separate from other ingredients if the liquids are left unused creating sediment in the bottle. So, before you get worried about possible expired e-liquid, ask yourself how does it smell, look and is the liquid free of any solids. If the vape juice looks and smells fine, then enjoy it. The best advice u can get, is you are your best judge, so judge the liquids yourself. If you are worried about something, don't use it and throw it out.