Unused prescription medications account for more accidental poisonings in the home than any other product. So it's important to get rid of them. But some medicines might also cause harm if they are flushed down toilets, poured down drains, or end up in drinking water supplies. Here's what you can do to help prevent pollution from unused meds.

The following advice was adapted from the White House Office of National Drug Control Policy.

Take advantage of take-back programs. Some pharmacies or household hazardous waste programs will take back unused pharmaceuticals. To find out what your options are, ask or call your local pharmacy, or check with your state or local waste-management authority about collection programs.

Otherwise, mix and dispose. After removing prescription drugs from their containers, mix them with an undesirable substance, such as used coffee grounds or kitty litter to deter others (people and animals) from rummaging through the trash and finding them. Then put the waste in impermeable, nondescript containers, such as empty cans or sealable bags. Then place the waste in your trash. View a step-by-step video clip.

Know when to flush. Flush prescription drugs down the toilet only if the label or accompanying patient information instructs doing so, or if the drug is found in this list from the Food and Drug Administration.

—Kristi Wiedemann, science and policy analyst, CR Greener Choices

Read more on medicine cabinet dos and don'ts.