Whether you’re cleaning out the garage or are tidying up after dinner, some common household items have very specific disposal requirements you may or may not know. In fact, the improper disposal of some of these items can release toxic materials into the environment, which are harmful for people, wildlife, and the planet.

Before you take the trash to the curb, brush up on this list of common household items and how to safely dispose of them.

Cooking Oil
Oil should never go down the drain because it clogs plumbing and contaminates the water supply. Rather, wait for the cooking oil to cool and then pour it into a clean glass jar. You can reuse the oil or simply throw the container in the trash. You can also dispose of used cooking oil at your local hazardous waste collection site, or your city may collect it to make biodiesel.

Refrigerators, freezers, and air conditioners often contain CFC, which harms the ozone layer. Many cities and businesses offer CFC disposal services, but they may charge a fee. If the appliances are in working order, you may consider donating them to a local charity—they may even come pick them up.

Compact Fluorescent Lightbulbs
CFLs may be energy efficient, but they also contain toxic mercury. When the bulbs finally burn out, check your local home improvement stores for lightbulb recycling programs. This is the best way to ensure they’re disposed of properly. For a safer alternative, switch to LED lighting.

You may not know this, but cosmetics may contain harmful metals and petroleum products, including carcinogens. If you’re cleaning out your beauty drawer, be sure to put expired cosmetics in a sealed container before tossing. Some cosmetics companies will even ask that you send empty containers back to them for reuse.

Many people aren’t sure how to properly dispose of medication. Trashing or flushing medications is a common choice, but it only leads to toxic ingredients contaminating our water supply. Many pharmacies and hospitals offer medication disposal programs, so be sure to check before you flush.

Household Cleaners
The best way to dispose of household cleaners is to use them up or give them to a friend or family member. But, if you have household cleaners you need to get rid of, check the label for instructions. Most—like detergents and toilet bowl cleaners—are water soluble and can be flushed or poured down the drain with running water.

Pool or Spa Chemicals
Pool chemicals are expensive. If you have unused chemicals, see if a friend or family member can use them before tossing them. If you must, dispose of any used chemicals at your local household hazardous waste facility. Do not take them to the landfill, as this will directly release harmful toxins into the environment.