Diapers won’t expire, but they can deteriorate over time and lose elasticity. While this might make them less effective, older diapers don’t pose any health risks.

Have you ever wondered — but felt silly asking — if diapers expire?

This is actually a very reasonable question if you have old disposable diapers around and don’t know if they’ll make OK hand-me-downs when baby number 2 (or 3 or 4) comes along. Or maybe you’re considering gifting unopened, leftover diapers to a friend or relative.

Rather than toss unused diapers, why not use them later on, give them to friends with little ones, or donate them? The short answer is, you likely can, because they don’t expire — though age may have taken a toll in some cases.

Baby formula has an expiration date, and even baby wipes can lose moisture over time. But as far as diapers go, your friends, family, and even your pediatrician might be stumped by this question.

Frankly, it’s a question that most people never think about. If you search online for an answer, there isn’t much reliable information available.

The good news is that you no longer have to guess. We reached out to the customer service departments at two major disposable diaper manufacturers (Huggies and Pampers), and the general consensus is no, diapers don’t have an expiration date or shelf life. This applies to open and unopened diapers.

So if you have last year’s unused diapers laying around the house, don’t feel guilty about gifting these to someone else — hello, perfect baby shower gift.

And for ones that are even older? Well, as a paper product, diapers can be used for an unknown period of time. But while they don’t technically expire, manufacturers do recommend using them within 2 years of purchase.

This isn’t a hard or fast rule, though. Just know that there are some things to keep in mind with older diapers.

Color, absorption, and elasticity are considerations to keep in mind with diapers older than a couple years. These issues don’t signal that the diaper has expired — that is, it’s not dangerous to use a discolored, looser, or less absorbent diaper — but they may be reason to throw in the towel and go with another option (new diapers or even cloth diapers).

1. Discoloration

If you’re using diapers with some age, they may no longer appear white bright, but rather have a slight yellowish hue. This is something that commonly happens with paper products over time due to exposure to light and air.

But while yellow diapers might look past their prime, they’re safe to use and can be just as effective as a new pack — although we wouldn’t recommend gifting these to anyone.

2. Less absorption

Another thing to keep in mind with older diapers is that the absorption material may break down over time. And as a result, the diapers may become less effective with absorbing moisture, causing leaks.

So if you’re using an older pack of diapers and notice more leaks or wet surfaces, your best bet is to toss the diapers and buy a new pack. This way, your baby’s bottom remains as dry as possible, which can help prevent diaper rashes.

3. Less elasticity and adhesive

Older diapers can also suffer from loosened elastic around the legs, which can cause more leaks. In addition, the adhesive tape used to keep diapers in place can break down after a couple years. The last thing you want is a diaper that slips off due to weak adhesive!

Because some disposable diapers contain chemical components, you might prefer natural diapers made from plant materials — like the ones from The Honest Company.

According to The Honest Company customer service representative we spoke to, their hypoallergenic, eco-friendly disposable diapers also don’t have an expiration date. But like other diapers, they could potentially lose effectiveness the longer you have them.

Since the goal is to keep your diapers in good condition — so they don’t lose their effectiveness and leave you with a big mess — it’s important to know the proper way to store diapers.

Pampers recommends keeping diapers in an “area protected from extreme heat and humidity.” The company also recommends a storage area that’s 85°F (29.4°C) or less. Too much heat can melt the adhesive tape on disposable diapers, causing less stickiness.

Also, if you have more diapers than you’ll need, keep them packaged in the box and plastic, if possible. This eliminates direct exposure to light and air, which helps reduce the yellowing effect.

Diapers are expensive, so the fact that they don’t have an expiration date might be the best news you’ve heard — especially if you have a bunch of unused diapers around and you’re expecting a new baby.

But although diapers don’t expire, they could lose effectiveness. So keep a close eye on how well your older diapers perform. If your baby starts to have more leaks than normal, it’s time to toss them in favor of new ones.