   Understanding Pesticide Labels - June 10, 2009 Jeff Schalau, Associate Agent, Agriculture & Natural Resources University of Arizona Cooperative Extension, Yavapai County Many gardeners will opt to use a pesticide when a pest is causing significant damage to their garden or landscape. Before doing so, it is important to correctly identify the pest, identify the appropriate pesticide, consider the short- and long-term implications of your actions, and how to protect yourself and non-target organisms in the process. All of this information is provided on the pesticide label. Many products sold today have a small booklet or folded sheet attached to the container with detailed information about that product. This is the pesticide label. You should read this document in its entirety before mixing, applying, and after application of that product. It is illegal to use a pesticide in any way inconsistent with the label. Some gardeners choose to avoid the use of pesticides. Others use pesticides and don't realize it. Examples of pesticides are: cockroach sprays and baits; insect repellents for personal use; rat and other rodent poisons; flea and tick sprays, powders, and pet flea/tick collars; kitchen, laundry, and bath disinfectants and sanitizers; products that kill mold and mildew; some lawn and garden products, such as weed killers; and some swimming pool chemicals. Organic gardeners also use pesticides. Some examples of approved organic pesticides are: rotenone, neem tree oil, and insecticidal soap. Pesticides are usually identified in reference materials by their product name (also known as trade name or brand name). This is prominently displayed at the top of the pesticide label. Product name examples are: Roundup, Weed B Gone, Neemix, Merit, etc. Many companies use the same basic product name to designate different pesticide formulations. An example is Roundup. Monsanto markets Roundup Original, Roundup Pro, Roundup Ultra, and many more. All of these Roundup products contain a common name for the active ingredient called glyphosate. The difference is in the formulation or concentration. Other companies now market herbicides containing the active ingredient glyphosate. The active ingredient(s) are always listed as a percentage by weight of the total product on the pesticide label. A chemical name is also listed for each active ingredient. These are names that may mean something to an organic chemist, but are usually unpronounceable by the rest of the population. The chemical name for glyphosate is N-(phosphonomethyl) Glycine. The signal words DANGER, WARNING, or CAUTION must appear in large letters on the pesticide label. The signal word indicates how acutely toxic the product is to humans. The signal word is always followed by the statement: KEEP OUT OF REACH OF CHILDREN. The signal words are also associated with an LD50. The LD50 is the dosage by weight of the active ingredient that killed 50% of the rats studied during the registration process of that pesticide. DANGER indicates that the pesticide is highly toxic or hazardous. The product is very likely to cause acute illness from oral, dermal (skin), or inhalation exposure, and/or cause eye damage. The LD50 for labels bearing the DANGER designation is between 0 and 50 mg/Kg of body weight. A rough estimation is that a few drops to a teaspoon could kill the average person. WARNING indicates that the pesticide is moderately toxic. The product could likely cause acute illness from oral, dermal, or inhalation exposure or could cause moderate skin or eye injury. The LD50 for labels bearing the WARNING designation is between 50 and 500 mg/Kg of body weight. Here, a rough estimation is that a teaspoon to a tablespoon could kill the average person. CAUTION indicates that the pesticide is slightly toxic or relatively non-toxic. The product has only a slight potential to cause acute illness from oral, dermal, or inhalation exposure. Skin or eye irritation it would cause, if any, is likely to be slight. The LD50 for labels bearing the CAUTION designation is between 500 and up mg/Kg of body weight. Here, a rough estimation is that a tablespoon to a pint could kill the average person. Naming of companies or products is neither meant to imply endorsement by the author nor criticism of similar companies or products not mentioned. The University of Arizona Cooperative Extension has publications and information on gardening and pest control. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 ext. 14 or E-mail us at cottonwoodmg@yahoo.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://cals.arizona.edu/yavapai/anr/hort/byg/. |