Why do seemingly non-perishable items — like rubbing alcohol, dental floss and body lotion — have expiration dates?


Was flossing my teeth this morning and read on the box that it has an expiration date of 2020. Why?


While there is actual chemical breakdown where certain items eventually do become less effective or physically break down (items from 1970 would likely not be very effective for instance), most of it’s marketing designed to get people to toss stuff out and replace it.

It’s even the same with foods: The ‘best by’ date has a grain of truth to it as far as when it begins to chemically alter and lose its desired taste, but is NOT the same thing as an ‘expiration date,’ something that only applies to certain food items (mostly baby products, dairy, etc). Very often canned and dried goods can survive much, much longer than people think and get tossed for no reason at all.

Don’t take this as an invitation to eat random 30 year old tins of beans, mind you, since things can definitely go bad and in dangerous ways, but chances are you can ignore the date on dental floss or lotion.

Disclaimer: this is an educated guess, but my understanding is that exposure to air and/or moisture (even if that moisture is just from the air) can cause things to deteriorate or change such that their original makeup or effectiveness changes. At that point, while it may not appear bad it is essentially expired.

The FDA requires everything that it regulates to have an expiration date no later than 2 years from the date it was made unless the manufacturer can prove that the product lasts longer than that. Its expensive to prove that a product lasts longer than 2 years, and so most manufacturers just slap the 2 year expiration date on non-perishable goods.

Dental floss is regulated by the FDA and so is subject to that expiration date requirement.

It’s not only about the product itself, but about the integrity of the packaging it comes in.

As that packaging deteriorates or becomes compromised somehow, air/water/bacteria/etc. as well elements of the broken down packaging can enter and affect/compromise the product inside, possibly as far as making the product unsafe for use/consumption.

That’s why even centuries-old Himalayan sea salt sold in stores carries a use-by date.

Rubbing alcohol will absorb water over time and become less effective. Dental floss will eventually oxidize and become brittle. The water in body lotion will evaporate and it will also oxidize.

Everything goes bad eventually.