by Niki L. Moquist, UC Master Gardener

Spring is the perfect time to inventory our garden and household chemicals sitting in the garage or garden shed shelves. These half or full containers might have sat around for a while gathering dust. These need to be disposed safely to prevent accidents and protect the environment. 

Let’s define what is a pesticide: A pesticide is any substance used to kill, repel, or control certain forms of plant or animal life that are considered pests. A pest is any unwanted organism that causes problems. Most organisms are not pests or are pests only in certain conditions. Pesticides should be considered tools or steps in a process.

Pesticides include: herbicides for destroying weeds and other unwanted vegetation; insecticides for controlling a wide variety of insects; fungicides used to prevent the growth of molds and mildew; disinfectants for preventing the spread of bacteria; and compounds used to control mice and rats. They can be chemical, or organic such as neem oils. They contain active and inert ingredients, produced to be used in very specific ways. 

Labels on pesticide containers give specific instructions how to use and dispose, look for the “Storage and Disposal” statement on your pesticide label. It is a good idea to learn how to read the pesticide label. Labels are there primarily to help us achieve maximum benefits with minimum risk. Both depend on following label directions and correctly using them. Follow the directions before each use and when storing or disposing the pesticide. Do not trust your memory. You may have forgotten part of the instructions. Use of any pesticide in any way that does not comply with the label direction and precautions is illegal. Improper usage may be ineffective on the pests or, even worse, pose risks to users or the environment. Labels also list if the pesticide is toxic to the bee population. It is a good idea to read the label prior to purchasing a product to make sure is effective on the pest you are trying to control. Keep product in its original container with labels intact.

Dispose of pesticides as instructed on the product label. If product label is illegible and contents cannot be identified, it is best to dispose. Some chemicals do not age well, if they have been sitting on a shelf for a while it is best to dispose. Older chemicals might have been removed from the market and it would be illegal to use them, e.g., diazinon. (The last time use allowed was 2004!). If any product remains in the old container, it must be disposed as household hazardous waste. Never pour pesticides down the sink, toilet, sewer, or street drain. Many municipal drinking water and wastewater treatment systems are not equipped to remove pesticides. If pesticides reach waterways, they can harm fish, plants, and other living things. You cannot dispose pesticide bottles or other containers in household garbage can. You need to take them to an approved Household Hazardous Waste Center. Check your local municipality for hours and sites. Never reuse empty containers.

Once ready to tackle the task, make sure to line the floor with a heavy plastic tarp. Have on hand kitty litter or sand and plenty of paper towels for cleaning spills. Lay out heavy garbage bags to form a barrier for plastic containers. Be sure to wear protective clothing when rinsing pesticide containers, such as chemical resistant gloves and eye protection to avoid contact with skin or eyes. Do not pour rinse water into any drain or on any site not listed on the product label; it could contaminate the environment. If you mixed or diluted a pesticide and you have a little too much left over, try to use it up while following the label.  Consider asking a neighbor if they can use any leftover mixtures. Protect pets and children, make sure they are in the house and safe.

How to transport the old pesticides to the Household Hazardous Waste Center:

  • Keep the pesticides in their original containers with the labels attached
  • Place containers so they won’t shift and/or spill; you might have to fill gaps between containers with old newspapers
  • Line the transport area in your vehicle with a heavy plastic tarp, to contain any spills in case of an accident
  • If pesticides are carried in the back of an open vehicle, secure and cover the load
  • Don’t put pesticides in the passenger compartment of a vehicle

Go straight to collection site once you have loaded the car. Drive carefully

Same rules apply when you purchase pesticides and are delivering them to your house. Place bottles in a plastic tub lined with a heavy garbage bag, to protect your vehicle in case of spills. Keep pesticides away from groceries, including food for animals.

Pesticides should be stored in their original containers. The original container is designed to protect the product and it’s made of materials that will withstand the chemicals in the product. Store containers with their original labeling which includes application and disposal directions, ingredient names and emergency information. The original container also has the appropriate lid/cap to protect kids and pets. Store in a designated place that is only used for pesticide storage, pick a well-ventilated location that children and pets cannot access, preferably with a latch or lock. Choose a location away from ponds, streams and drinking water wells.

Keep these tips in mind:

  • Practice Integrated Pest Management (IPM) to reduce the use of pesticides (see below for website)
  • Identify the pest and make sure the product will be effective against that pest before purchasing
  • Buy only what you need for the season, mix only what you need today, follow label directions for mixing

Helpful Resources:

  • For help with identifying pests and how to control them – Integrated Pest Management Program at University of California  http://ipm.ucanr.edu/PMG/menu.homegarden.html  
  • For help in how to store, dispose, read labels on container, the National Pesticide Information (NIPC) at Oregon State University is a good source.  
  • Disposal Instructions on Non-antimicrobial Residential or Household Use Pesticide Product Labels –US Environmental Protection Agency (EPA
  • Safe Disposal of Pesticides – US Environmental Protection Agency (EPA)
  • Contact your local Master Gardeners for more information

Happy gardening and stay safe.