The old adage "waste not, want not" was probably drilled into your brain from an early age. Throwing something away isn't always a bad thing, though — in fact, hanging on to old stuff can actually put your life in danger. From filters to medicines, we're rounding up the household objects you should remove or replace today. Some might surprise you, so get ready to check those labels! Air Conditioner Filters Throw it away: Every 1 to 2 months Your air conditioner works hard to keep you comfy, especially during the summer. But if you never change its filter, you're making it work even harder. And over time, a dirty filter can reduce your AC's effectiveness. "With normal airflow obstructed, air that bypasses the filter may carry dirt directly into the evaporator coil and impair the coil's heat-absorbing capacity," according to the U.S. Department of Energy. That's why you should clean or replace filters (depending on their type) at least every one to two months. Homes with very furry pets might want to change them more often than that. SEE ALSO: Your No-Sweat Guide to Buying a Fan Cosmetics Throw it away: Every 2 months to 2 years Listen, folks: Spoiled, flaky makeup ain't cute. In fact, cosmetics that have gone over can present a real health hazard, especially when it comes to eye products. According to Allure, the item you'll want to toss most often is mascara, which has a shelf life of just two to three months. In fact, most eye products should be replaced within three months. Cream foundations and lipsticks can last up to a year, while powders can hang around for up to two years (with the exception of powdered eye shadows, of course). Nail polish is trickier to pin down. It's not going to spoil, but throw it out if the lacquer gets dry or clumpy. Athletic Shoes Throw it away: Every 300 to 500 miles, or after 45 to 60 hours of sports use If exercise is a pain, your favorite sneakers may be to blame. It's easy to spot outsole warning signs like a worn-down tread or obvious creasing, but an old midsole can be harder to detect — and therefore more likely to cause injury. According to the American Academy of Podiatric Sports Medicine, midsoles lose their shock-absorbing capabilities with prolonged use. Your midsoles (and thus, your shoes) will be worn out "after 300 to 500 miles of running or walking, or 45 to 60 hours of basketball, aerobic dance, or tennis." Kitchen Sponges Throw it away: Every 1 to 2 weeks How disgusting is your old kitchen sponge? Pretty darn disgusting! "A sponge can harbor 10 million bacteria per square inch and can be as much as 200,000 times dirtier than a toilet seat," according to The Wall Street Journal. Even the cleanest, most well-kept sponges need to be tossed about two to four times a month. In between replacements, you can run your current sponge through the dishwasher to help keep germs at bay. Plastic Storage Containers Throw it away: When deformed or discolored Convenient as they are, these little cups and bowls will break down over time, especially if you're always using them in the microwave. Phthalates and BPA are plastic components found in some storage containers that can leach into food when the plastic is heated. "Old, cracked containers and those that have been washed hundreds of times" are the biggest offenders, according to WSJ. While the health risks of these chemicals aren't fully understood, it's a safe bet that you don't want them in your leftovers. Non-Stick Cookware Throw it away: When the coating is flaking off You want your salmon to be flaky, not your non-stick pan. While Lifehacker recommends you first try to clean your old cookware, it notes there's nothing to be done for a non-stick surface that's peeling up: "If non-stick pans are flaking off because of scratches, they should be replaced. If nothing else, it's just kind of gross to eat a part of your pan." Of course, taking good care of your pots and pans can preserve them for years. SEE ALSO: 5 Items You Can Buy Once (And They'll Last) Prescription Drugs Throw it away: About a year after the expiration date First of all, your friendly neighborhood pharmacist can tell you how to dispose of medication properly. Some meds are flushable, some are tossable, and some need special handling — it's better for the environment, pets, and everybody if you know the difference. Now, according to Consumer Reports, most prescription medications should be thrown out about a year after the expiration date has lapsed. Many old drugs won't actually harm you, but they may become less potent over time. However, some medications (like tetracycline) can actually become toxic after awhile. Don't take the risk! Alcohol Throw it away: After it's been open for a few days or a few months, depending on type Unopened alcohol behaves very differently from opened alcohol. An unopened bottle of good wine will only get better over the years, but once it's open you'd better drink it quick. According to Flask.com, "Wines don't stand up well to the process of oxidization, and even if you do your damndest to stuff the cork back in or keep it in the fridge, it will only be good for a few days." Hard liquor will keep forever once opened, but the flavor will diminish as it's exposed to oxygen. Flavored liqueurs will actually spoil, so check your expiration dates whether you've opened them or not. Unlike wine, beer isn't meant to be kept around; most bottles have a shelf life of several months. Car Parts Throw it away: Every 3,000 miles to 100,000 miles Everyone knows you've gotta replace your air filter (every 30,000 miles), and change that oil (check your manual, but it could be up to every 7,500 miles). However, cars are full of less common parts that need periodic switch-ups. AskMen has a great car part replacement calendar, but nothing can replace regularly scheduled maintenance. Don't wait until you hear a funny noise! SEE ALSO: Here's Why You Should Think Twice Before Using Tire Sealant Fire Extinguishers Throw it away: After 3 to 12 years Unlike a smoke detector, your fire extinguisher has no annoyingly loud beeps to tell you when it's dying. "To ensure the extinguisher will work when needed, it needs to be within rated age limits; have the recommended charge as indicated on the pressure gauge; and undergo periodic inspection for dents, corrosion, and integrity of the safety pin," The Seattle Times reported. Depending on the model, fire extinguishers are good for three to 12 years; check the labeling on yours to see if it's still okay. Most importantly, an extinguisher is only good for one use. Toss yours if you've ever tried it out. Readers, did we miss anything in our list of things to toss? What household objects do you always keep for way too long? Let us know in the comments below! Related DealNews Blog Posts: 5 DIY Projects You Should Leave to the Pros 5 Items You Can Buy Once (And They'll Last) Don't Sweat It! 9 Tips for Getting Air Conditioning on a Budget
