Most people know when to buy a new toothbrush, wash their bathroom towels or toss out a dirty sponge. However, the right time to replace other household items may not be as straightforward.

While certain items last longer than others — particularly those that are more expensive — their life span ultimately depends on how often you use, clean and maintain them.

Of course, even regular care won't prevent the gradual wear of your belongings — and not doing so could potentially impact your health and well-being. Here are six things you probably should replace in your home sooner rather than later.

1.  Air Filters

According to the U.S. Centers for Disease Control and Prevention (CDC), Americans spend about 90% of their time indoors, where pollutants are about two to five times greater than outdoor concentrations.

Air filters adequately capture dust and particles in the air but are often an overlooked maintenance routine when it comes to upholding indoor air quality.

Most air filters are either fiberglass or pleated, both of which are disposable and easy to purchase at home improvement and grocery retail stores. Look at your HVAC system manual to determine your specific air filter requirements, such as size, for example you may need a 21x21x1 air filter (measurements are in inches) and recommended replacement schedule.

Although less expensive than pleated air filters, fiberglass air filters aren't as effective at catching pollutants and must be changed every 30 days or less. Meanwhile, pleated air filters can last up to 90 days.

2.  Water Filters

While drinking water typically contains trace amounts of biological and chemical contaminants — arsenic, lead, copper, nitrates, mercury, bacteria and viruses, etc. — higher levels may pose a public health risk.

Drinking water chemical exposure could potentially lead to cancer, heart disease, infertility and developmental issues in children. For example, 43.2% of well water in Maryland fails to meet federal water standards, containing fecal and other microbial pollutants. Another study recently found that atrazine contaminants in drinking water contributed to lower birth weights in Ohio.

Regardless of whether it's a pitcher, refrigerator or faucet, it's critical to purchase and install a new water filter. However, every filtration system is different, so check the manual for the most accurate guidance.

3.  Smoke and Carbon Monoxide Detectors

Fire departments in the U.S. responded to nearly 346,800 house fires between 2015 and 2019. Another 170 Americans die from carbon monoxide poisoning every year due to non-automotive appliances, such as water heaters, furnaces and portable generators.

Replacing old or broken smoke and carbon monoxide detectors is a simple, life-saving precaution that can prevent injury or worse. Between 2014 to 2018, three out of five fire-related deaths occurred in 41% of homes without smoke detectors and 16% with faulty alarms.

On average, carbon monoxide detectors last seven years and will either beep or display an error message when it's time to replace the battery. Newer smoke detector models are also designed to last ten years, the age at which you should replace the entire device.

4.  Fire Extinguisher

As you replace your smoke and carbon monoxide detectors, you might also want to inspect your fire extinguisher.

The general rule of thumb is to replace your fire extinguisher after 10 to 12 years, as long as it isn't corroded or broken. Storing your fire extinguisher below 40° Fahrenheit or above 120° F can also reduce life expectancy.

Every year, check your fire extinguisher to ensure the seal and locking pin is intact. You should also look for signs of corrosion and leaks, that the pressure gauge is still operable and for a sturdy handle.

Additionally, store your fire extinguisher where it's easily accessible, away from chemicals and high heat and somewhere it won't get dented or damaged.

5.  Dishwashers and Washing Machines

Appliances make cleaning household items far more convenient than doing it by hand. However, even they need regular upkeep and replacements.

Your dishwasher's life span is about 10 years, although nearly 30% of purchased dishwashers develop problems within the first five years. Meanwhile, washing machines can last about 14 years with an average of seven loads per week. Of course, the more stress you place on it, the more likely it'll require expensive repairs much sooner.

Purchasing new appliances is an investment but necessary when they stop functioning correctly. If you run a load of dishes or laundry and the water doesn't get hot, harmful bacteria are more likely to linger on your kitchenware and clothing.

6.  Carpet

Your carpeting sees a lot of traffic, from bare feet to dirty sneakers, leaving behind pet dander, allergens, food and other debris within the fibers.

Even if you find yourself vacuuming several times a week or deep cleaning your rugs every six months, replacing them is often unavoidable.

You should swap your carpet out every 15 years, although some carpeting requires replacing as soon as five years. Anyway, you can always check for a carpet replacement quote online.

If you're unsure of your carpet's age, common signs it's time to get rid of them include stains, matting and tears, foul odors, worn padding, color loss and fading, wrinkles and increasing allergy or asthma symptoms.

Responsible Homeowners Get It Done

Certain household items are more challenging and expensive to replace than others, but doing so can significantly improve the health and safety of everyone in your home. After all, being a responsible homeowner means taking care of the essentials when absolutely necessary.