You may be one of the lucky few who find a drawerful of civil war medals and emeralds in an old dresser drawer. If not, garage sales can still offer a treasure trove of books, vintage clothing and household items you wonder how you ever did without (antique salt shakers, anyone?).

But Alex Filip of the Consumer Product Safety Commission (CPSC) warns that weekend pickers should be careful before closing a deal. To be on the safe side, it may be better to stay away from some products, like the ones listed below, as they may be unsafe.

Related: How to Know If Used Baby Gear Is Safe

Unfortunately, some of these goods are like catnip for garage sale buffs. So if you’re tempted to bend this garage sale “do not buy” list, the CPSC has some advice: Use your smart phone do some research on the spot. Apps that link to federal safety websites now give consumers a quick way to check if a product's been recalled. Or go directly to the CPSC website, where you can search by product or brand name. Another site the CPSC hosts, Safer Products, is more comprehensive. There you can sift through a wealth of product reports and complaints from consumers, even for items that haven’t been recalled.

In addition, you can look for all the products that fall under the jurisdiction of the Food and Drug Administration on their recall site.

Cribs

Cribs, especially the drop side variety, are often on recall lists since children can become wedged or trapped in unintended spaces. Drop-side cribs, in particular, were involved in a number of infant injuries and deaths.

Even if a crib doesn't have a drop side, the CPSC warns that you should avoid purchasing a used crib. “It just isn’t worth the cost savings,” warns the CPSC’s Patty Davis.

Car seats

Car seats are another common item parents love to snap up. But while the National Transportation and Highway Safety Administration (NHTSA) says it is OK to use a car seat that has been in a minor accident, a moderate accident can compromise its safety. Since you can’t get the lowdown on a car seat’s history, it is better to buy new.

If you must consider a used car seat, check NHTSA’s consumer website or call its recall hotline. Don’t count on the seller to tell you its defects: A writer living in Berkeley recalls that she once purchased what she thought was a great deal — a barely used $375 car seat for $50. When she looked it up online several days later, she realized why the owner may have been anxious to unload it: The manufacturer had recalled it for serious safety flaws.

Pediatricians’ associations say that if you must buy a used car seat, make sure it is free of cracks and not missing any parts. And never buy one without a manufacturer's label that allows you to check for recalls or safety concerns.

Bike helmets

As with car seats, helmets used for bikes and scooters are not safe after they’ve been in an accident. But unlike car seats, bike helmets are rendered practically useless after even a minor accident. Add to that the risk of getting bedbugs or lice from used, unwashed headgear and you'll see it's much better to shell out the money for a new helmet. If money is tight, check with your local police station and fire department: They often sponsor safety days that may include free or low-cost helmets.

Toys

It is hard to pass up a cute stuffed animal or scooter at a yard sale, but that’s the safest option. Stuffed animals are often home to bedbugs and lice, so if you do break down and get one — bag it, wash it right away and dry it on “high” for at least 20 minutes.

Watch out, too, for used laser toys and mechanical toys and figurines, which often have loose small parts (a choking hazard) and may have been recalled for other problems such as lead paint.

Finally, avoid the $1 to $2 grab-bags of delightful small toys. One colleague recalls watching her daughter open such a bag and put something in her mouth. When the parent asked her to hand it over, she was horrified to find a button magnet (which, if swallowed, could have caused extensive intestinal damage and even death).

Tires

Better to buy new: Rubber not only loses elasticity over time, but you can’t always tell how safe a tire is by tread wear alone. According to NHTSA, accidents or incorrect use — high speeds, underinflation and tire overload — can lead to damage on the inside of the tire that you can’t necessarily see. The hotter the climate, the faster this often-invisible damage can occur.

Related: Are your All-Season Tires Really Good Enough for Winter?

Mattresses and couches

Pest companies such as Orkin have seen a 33 percent increase in calls related to bedbugs in recent years, and mattresses (and upholstered furniture) are ground zero for bedbug transmission. Old mattresses and couches also can harbor lice and mold, and those manufactured before 2007 are not up to current fire standards. Some crib mattresses have also been recalled. Invest in some peace of mind and buy a new couch or mattress.

Related: What's Hiding in your Mattress?

Shoes and hats

Great clothes are coveted items at garage sales, and if they're washed immediately in hot water, you can reduce the risk of lice or bedbugs in your home. But some items, including shoes and hats, are better bought new.

The American Podiatric Medical Association’s watchword is “never hand down shoes.” Wear patterns on a new user’s foot can be different enough to cause back or leg pain or even injury. Used shoes can also harbor fungus.

And even seasoned garage sale aficionados may turn down hats due to worries about lice. Unless a hat can be washed in hot water, it’s not worth the risk.

Extension cords

Don’t court trouble: More than one million counterfeit electrical products, including extension cords, power strips, batteries and hair dryers, have been recalled in recent years. Knock-off extension cords from overseas are untested and often have safety defects that can cause serious and even fatal house fires, according to the Consumer Product Safety Commission. They continue to be a found at deep discount stores and make their way to garage sales, sometimes in new packaging with a fake UL mark.

Used cords that are cracked or damaged are also a real hazard, so the CPSC recommends consumers never buy used extension cords (and buy new ones only at reputable stores). In addition, never buy a cord that hasn’t been approved by an independent safety testing laboratory, such as UL. While you're at it, pass up those batteries and hair dryers, too.

Related: Don't Let a Battery Set Your House on Fire

Nonstick pots and pans

Even eBay recommends that consumers not buy used coated pans. Many websites say not to buy scratched nonstick cookware, but experts disagree over the degree of hazard. The real danger, according to chemist Robert Wolke, PhD, author of "What Einstein Told His Cook: Kitchen Science Explained," is that the coating on some nonstick cookware begins to degrade at temperatures over 500 degrees, releasing chemicals that may be toxic. Since you can’t know the history of a pan, it is better to be safe and buy a new one. Furthermore, “if it is old and scratched, food can get caught in the cracks and cause bacterial growth if it isn’t cleaned properly,” says Wolke.

Kathryn Olney is a freelance writer and editor who has served as a reporter and editor for California, San Francisco and Mother Jones magazines.