Think Before You Buy a Pesticide [fact sheet]

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Read the label before you buy!

Make certain a pesticide you are considering buying is labeled for your intended purpose. That means the pest that you wish to control (Indian meal moth, two-spotted spider mite, apple scab, crabgrass) must be mentioned on the label, as well as the site where you plan to use the pesticide (in a home, in a greenhouse, on apple trees, in a lawn).

Both the pest and the site need to be mentioned on the label in order to use it legally for that purpose. If they are not on the label, look for another form of the product or another product with different active ingredients. Sometimes the label lists the target pests more broadly, like “beetles on shrubs.” In that case you could use it on your shrub to control any beetle.

If you don’t read the label first, you may be stuck with a product that is illegal for your intended purpose – a product you may you may not be able to return. Th e label will also tell you if the product could be useful for other pests besides the problem you have.

Is this an appropriate size to buy?

The label will tell how much of the product to apply. If it says to use 1 teaspoon mixed in a gallon of water, that would tell you that a pint jar of that product would make 96 gallons of spray! Do you expect to use this just once or twice a year? If that is the case, then 1 pint might be more than you would use in many years.

Doing the arithmetic before you buy might save you from big problems later. Even if the price sounds good, why buy much more than you will use in five or six years, leaving you with leftovers you have to dispose of through hazardous waste procedures?

How long will it last in storage?

If stored properly (in a cool, dry area that doesn’t freeze), many chemical pesticides will last for several years. A few might still be effective after 10 years. Some of the biological pesticides will have shorter storage life. The label often gives a telephone number to call if you wonder about storage life or have other questions about the product.

Where will you store it?

Pesticides (even biological pesticides) should be stored in safe, sheltered areas that are out of reach of children. Do you have an appropriate spot to store this material safely? Never store pesticides near food products. What would happen if a container broke or leaked?

How must I dispose of leftover product?

With very few exceptions, leftover pesticides will pose a serious disposal problem. If they are still good, perhaps you can give them to someone who can use them, following label directions. If you do choose to dispose of left over pesticides, do not bury them or dump them down a drain or toilet. Dumping or burying could result in serious contamination of soil or groundwater that could last for decades. It would also be illegal and cleanup could be incredibly expensive. Instead, place full or partially-full containers of pesticide in a large plastic bag and store them in a cool, dry place for disposal during your town’s next household hazardous waste (HHW) collection day. If a container of liquid is leaking, place the entire container into a larger, sealed container such as a coffee can or an empty paint can. Most New Hampshire communities currently host a household hazardous waste collection at least once a year. Call solid waste officials in your community for dates and times of collections. If your town does not participate in an HHW collection, call the NH Department of Environmental Services at (603) 271-2047 for assistance.

What form is appropriate for you?

Pesticides come in a variety of formulations. Products that will be mixed with water and sprayed onto surfaces include wettable powders, flowable liquids, and emulsifiable concentrates. Granular forms are intended to be scattered over a surface, or to settle in clumps in water. Baits often come in granular form. Dusts are not commonly used today. They are applied (dry) with special equipment that causes them to settle on surfaces. Pressurized cans (“aerosol bombs”) are handy, but are not designed to leave a significant chemical residue on surfaces. They can be very effective for flying insects. Fumigant strips are designed to be placed in enclosed areas, and the volatile pesticide fumes penetrate to fill the space.

Why spray if a swatter will do?

If the pests are easy to handle with fly swatters, why purchase expensive chemicals that might pose risks to yourself or others? Other nonchemical options, such as practicing good garden sanitation, planting resistant varieties and using barriers (such as floating row covers over plants), can be easy, effective ways to control insect pests. Th ere’s no need for chemical controls if other options are effective. Please think carefully before you buy a pesticide. Pesticides are easy to buy, but difficult to dispose of properly.

Download the resource for the complete fact sheet.


Former Entomology & IPM State Specialist, Emeritus
Phone: 603-862-1734
Office: Cooperative Extension, Spaulding Rm 252, Durham, NH 03824