8 Things You Should Never Buy Used

We’re all about finding great deals on stuff, but sometimes drawing the line between secondhand and spoiled can be tricky. Some items — like tables, art, and gym equipment — are more than worthy of a second (or third or fourth) life, while others are best left alone after use. That’s why it pays to know what kinds of goods are okay to purchase pre-owned, and which ones are best bought brand new. From worn out shoes to vacuum cleaners, here are nine items you should never buy used.

As a general rule of thumb, any pots or pans with scratched non-stick surfaces are definitely not a good idea to buy used. When scraped or chipped, the harmful chemicals that comprise non-stick coatings (like Teflon) can release into the air and your food. So spare yourself the carcinogens and just splurge on a new skillet.

We know brand new car seats can be expensive, but in some cases, the risks associated with used ones just aren’t worth the dollars saved. Not only do most car seats have an actual expiration date (due in part to the constantly improving safety technology), it’s sometimes difficult to determine whether or not a secondhand version is damaged or not—making it a dangerous chance to take over a few dollars.

A cheap mattress is hard to find, so it makes sense that a secondhand version might seem like a deal. However, once you take into account the possibility of bed bugs and dust mites—not to mention dead skin and bodily fluids—we’re guessing you’ll realize you’re much better off just splurging on a new one.

Look, we love makeup as much as the next person, but using hand-me-down cosmetics—even when coming from your sister or best friend—is never a good idea. Unless the package remains unopened (and we mean intact seal and all) don’t subject your skin to other people’s oil, bacteria, and bodily fluids with soiled secondhand makeup.

Although scoring a pre-worn pair of otherwise pricey shoes can be enticing, there’s more than one reason you should stay clear of used footwear. Along with potentially inheriting old foot fungus, sweat, and bacteria, shoes mold to their owner’s unique feet over time—meaning a broken-in pair can trigger foot and back pain in the long run.

Here’s something that might surprise you about bike helmets: most are designed to only withstand one major impact. And since it’s almost impossible to tell from the outside if a used helmet is damaged internally, there’s no reason to risk safety over saving a few bucks.

It probably goes without saying, but any kind of swimsuit (or undergarment for that matter) should be off limits when secondhand shopping. And considering how closely fitted to the body most swimsuits are, we’re guessing you’re not interested in acquiring someone else’s poor hygiene problems either.

Although a hand-me-down vacuum cleaner can seem like a steal, the potential dust mites and secondhand bacterium that come along with it are not such a great deal. (And, really, when has anybody ever gotten rid of a perfectly good vacuum cleaner?) Instead of picking up a used version from a stranger, try shopping for a factory-refurbished model online or splurge on a new one to ensure a proper clean.