Smoke Alarms

When to Toss: Ten years after purchase — that’s when they become unreliable. In the meantime, you should replace the batteries every year and test alarms monthly. If one flunks, junk it immediately, even if it’s not 10 years old.

How to Do It: Drop them off at a household hazardous waste center. To find the center closest to you, go to earth911.org and type in your zip code.

Fire Extinguishers

When to Toss: After 12 years — that’s when nonrechargeables start to lose pressure and become ineffective. Some can start depressurizing sooner, however. Have yours checked annually to make sure it still works. (To find a professional, look under “fire extinguisher services” in the Yellow Pages. The fee: about $10.)

How to Do It: Take them to a household hazardous waste center. To find one in your area, go to earth911.org and type in your zip code.

Mattresses

When to Toss: Every 8 to 10 years. By then, accumulated dirt, dust and allergens can’t be removed by regular cleaning. (Reminder: Flip and rotate your mattress every three months to keep it from getting lumpy.)

How to Do It: Call your trash collector to arrange a pickup or ask your new-mattress provider to take care of the removal.

Paint

When to Toss: Most latex house paints go bad after two to three years or after they have been exposed to freezing temperatures.

How to Do It: You need a household hazardous waste center that takes paint. To find one near you, go to earth911.org and type in your zip code.

Prescription Drugs

When to Toss: After their expiration date, which is when medications may begin to lose their effectiveness. Even if a medicine hasn’t yet expired, you should throw it out if you notice any change in color, odor or texture. These irregularities indicate that the medicine may have been exposed to moisture or heat, both of which can damage the medicine.

How to Do It: Take them to a household hazardous waste center. To find the one closest to you, go to earth911.org and type in your zip code. You can also put them in the trash. Just make sure the caps are on securely.

Running Shoes

When to Toss: After about 500 miles — that’s when materials start to break down. (If you use the shoes any longer, they could lead to a fall or injury.)

How to Do It: Put your worn-out shoes in the trash.

Batteries

When to Toss: Unused disposables become ineffective after seven years. Rechargeables stop taking a charge after three to five years.

How to Do It: Put disposables in the trash. Rechargeables contain toxic materials, so take them to a battery collection site (to find one nearby, go to rbrc.org).

Makeup

When to Toss: Bacteria can grow on cosmetics (especially liquid ones) after they’re opened, possibly causing skin irritation once applied. Also, products that are opened but long unused often become lumpy and hard to apply. Once opened, mascara and liquid liners should be discarded after three months; lipsticks and powder, one year; pencils, several years; foundations, six months.

How to Do It: Put old cosmetics in the trash. Then be sure to recycle glass and plastic bottles.

Eyeglasses

When to Toss: Whenever your prescription changes. (You should get a checkup at least once every two years.)

How to Do It: Donate your old pair to Lions Clubs International (lionsclubs.org ), which cleans and repairs glasses and distributes them to patients worldwide. Or save your frames and replace the lenses only.

Pressure Cooker Gaskets

When to Toss: After a year, or sooner, if the rubber has shrunk, stretched out or cracked, or if it’s sticky. A bad fit can cause a loss of pressure, and food will be cooked improperly. (Contact the manufacturer to find replacement gaskets.)

How to Do It: Dispose of gaskets in the household trash.