Ken Shackelton: Reading labels on herbicides and pesticides


— Reading the label is a good way to learn how and when to use an herbicide. A pesticide label can be intimidating but doesn't have to be. All pesticides used in the U.S. must be approved by the Environmental Protection Agency and must contain certain information. Learning what is in the label makes it easier to find the information you need. Some of the requirements are:

1. Classification

Classification designates whether the product is a restricted-use or general-use pesticide. General-use pesticides can be used by anyone, and no license is required. Most herbicides are general-use pesticides. Restricted-use pesticides can be used only by licensed applicators because of the potential to harm the environment or humans if they are not used properly. A label must state whether a product is a restricted-use pesticide; general-use pesticides are not marked as such.

2. Brand name, common name, chemical name, formulation and contents

The brand name is chosen by the manufacturer to identify the product. The EPA accepts the common name to describe the active ingredient. The name is specific to the active ingredient and used by all manufacturers of products containing that ingredient. The chemical name is just that - the name describing the chemical makeup of the active ingredient. For example, Tordon is a brand name, picloram is the common name of the active ingredient, and 4-amino-3,5,6-trichloropicolnic acid is the chemical name. Products with the same active ingredient may be marketed with different brand names. Sometimes the products are from competing companies and sometimes from the same company for different uses.

The amount of each active ingredient also is listed, by percentage of total volume. Always compare the common name and the amount of active ingredients when comparing competing products. The percentage of active ingredient may be the same, but in a weaker solution with less active ingredients. This either will decrease effectiveness or require more product to be used, increasing the cost.

Ready-to-use herbicides are another example of this. Manufacturers mix the product with water and sell it ready to be sprayed, often in a bottle with a squeeze pump. It is much cheaper to mix it yourself. Most of these products are marketed to homeowners for use in the yard. The convenience may be worth it for them.

3. EPA registration and establishment numbers

The registration number identifies the company and the product. The establishment number identifies which plant the product was made at.

4. Signal word

Signal words are "caution," "warning," "danger" or "danger - poison." The signal word indicates the general toxicity of the chemical. "Caution" is the least hazardous, and "danger - poison," accompanied by a skull and crossbones, is the most hazardous. The MSDS sheet and the precautionary statements on the label give more details about the specific hazards of the pesticide.

5. Precautionary statements

Precautionary statements give details about three types of hazards - "hazards to people and domestic animals," "environmental hazards" and "physical and chemical hazards." The statements also say how to minimize the risks.

"Hazards to people and domestic animals" gives specifics about the hazards to people and animals, including routes of entry and degree of risk such as "causes irreversible eye damage" or "causes eye irritation." Information then is given about how to avoid exposure, including what personal protective equipment to wear.

"Environmental Hazards" describes specific risks of environmental damage and steps to avoid the damage.

"Physical or chemical hazards" cover any fire, explosion or chemical hazards.

6. Directions for use

The directions for use tell how to use the product. This is the largest section of the label. It gives details about how to use the pesticide to achieve the desired results while minimizing problems. Included in this section are what weeds or pests the product controls and the different rates for each species, what plants it is safe to use on, replant intervals for crops if applicable, how to mix, directions for mixing with other herbicides, if a surfactant is needed and what type of surfactant.

7. General-use instructions

General-use instructions tell what type of plants an herbicide controls, such as broadleaf weeds, grass, brush, etc. and what type of sites or areas it can be used on. Any restriction around water and aquatic areas also is included.

8. Storage and disposal

Storage and disposal covers instructions on storage and disposal of unused product. The temperature at which it can be stored is important.

9. Practical treatments

Statement of practical treatment lists first-aid treatments for different types of exposure.

This is not a complete listing of what information is found on a pesticide label. The EPA requires certain information to be included, but there is leeway about how it is designed. Although most companies follow a similar pattern, there are enough differences to create confusion. Being familiar with what types of information is there helps. The basic format is similar for most labels.

The label is the law. It is against the law to use a pesticide in a manner inconsistent with the label. You can use a lower rate than is stated but cannot exceed the maximum rate. It can't be used in sites not listed but can be used on weeds that aren't on the label.

Take time to read the label, highlight sections that apply to you and mark out ones that don't.


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