I was opening a bottle of aspirin the other day. After I peeled back the plastic seal around the lid, I had to get a jar opener to unscrew the cap. Once I had done that, I had to get a knife, to scrape off the glued-on inner seal. Only then, was I able to use a pair of tweezers to remove the inner packing cotton. During all that process, I glanced at the expiration date on the package, and began asking myself about it. That led to more questions, and made me REALLY think about expirations.

Why is there an expiration date on canned goods? Why is there an expiration date on foodstuffs sealed in jars, like salad dressings, mayonnaise, pasta sauces, fruit juices, vitamins, aspirin, cough and cold remedies? Why is there an expiration date on first aid supplies, including essentially stable compounds like glycerin, mineral oil and tincture of iodine? Why is there an expiration date on hydrogen peroxide, which is stable in a closed container until it is exposed to oxygen?

Most packaged foodstuffs sold in the United States, provided they are stored in the way the seller intended, WILL NOT SPOIL. Most pharmaceuticals have an indefinite shelf life, as well. How can those pills packaged in those nasty little plastic and foil airtight, childproof (and some adult-proof) containers possibly spoil? So the expiration date must not really need to be followed, as it does not apply. It does not apply to anything that is sealed in an airtight package, unless and until the package has been opened. It CERTAINLY does not apply to freeze-dried items in undamaged packages.

The only exceptions are a few medicines, some meats, poultry and fish, and some dairy products.

So why does my salad dressing contain a “Best if Used by” (with month and year) label? Why are canned goods dated? Why does dry cereal, which is in a sealed container inside the box, have an expiration date? Why are vitamins, juices, frozen goods, and goods stored in sealed plastic inner wrappers labeled with a “sell by” or “Best By” or “Expires On” date?

Come to think of it, why do my lisinopril tablets expire EXACTLY one year from the date I purchased them?

Do these labels really mean anything?

I believe they do, but probably not in the way that most people think they do.

I think those labels are placed on goods so that the merchandiser cannot sell them after that time. The manufacturer wants to force the retail establishment to restock.

I asked my doctor about the expiration on my prescription medicines, and he said that the law requires that all prescriptions expire one year from the date the prescription is filled. He said that, if stored properly, the shelf life of most prescription pills are something on the order of about four years, and most liquids, provided they are kept cool, tightly capped, and out of UV light, about two or three years.

So I asked myself why the government would place such requirements on things. The only reason I can think of that makes any sense to me is that the laws are lobbied for by the food, medical and pharmaceutical industries. I suspect that also explains why many drugs are available over the counter in most European countries, while in the United States, a prescription is required for them. If I were a doctor, I’d think it in my best interest to require as many drugs as possible only be available for dispensation by prescription.

Fortunately, some drugs are used in farming, as well as by humans. Amoxycillin, for example, is available at my local feed store. The container is marked for veterinary use, but the contents and strength are exactly the same as the prescription I have to pay twice or three times as much for at my local pharmacy.