What is Sevin (Carbaryl) Pesticide?

Sevin® is a trademark for the insecticide commonly called carbaryl. One chemical name for the substance is 1-napthyl N-methylcarbamate. The "napthyl" portion of the name refers to its substituted napthalene ring. One means of manufacturing the pesticide is to react methyl isocyanate with 1-napthol. This is the reaction that so tragically caused thousands of deaths the notorious industrial accident at Bhopal, India, in 1984.¹ It was not the carbaryl, itself, that caused the disaster, but the methyl isocyanate vapors that leaked into the atmosphere outside the plant.

While horrible, the Bhopal disaster does not constitute evidence the pesticide is ineffective and should not be used. To illustrate, the electricity that illuminates our home also has been responsible for many electrocution deaths. How many of us would, for that reason, not take desire this utility?

Sevin - Store Availability

Sevin is readily available to the consumer, and is considered relatively safe to use. The Centers for Disease Control and Prevention provides a "NIOSH Pocket Guide to Carbaryl." Sevin is very commonly seen in dust form, although it is available as a granular, a liquid spray, as a hose-end formulation, and as concentrate. Each comes with instructions, which should be carefully followed. It may be applied throughout the growing season. Sevin may be purchased from hardware stores, department stores, as well as online. Additional products that contain carbaryl include Adios®, Carbamec®, and Slam®.

Effectiveness

Carbaryl affects the nervous systems of insects by blocking access to the neurotransmitter acetylcholine. The Garden Tech website says Sevin is useful against practically any insect. To illustrate: if applied to lawns, it is effective against ants, army worms, billbugs, centipedes, chiggers, crane flies, chinch bugs, cutworms, deer ticks, fleas, grasshoppers, Japanese beetles, leafhoppers, millipedes, ticks, and white grubs.

It ought to be mentioned that Sevin is perhaps a little too effective in that it kills honeybees, earthworms, and other useful insects as well as those considered undesirable. For this reason, in the vegetable garden it may be beneficial to get by with less effective insecticides if possible, such as pyrethrum or rotenone. If you choose to use Sevin, do so sparingly and perhaps away from flowers-for instance, squash blooms. After harvesting, be sure to wash the vegetables well. Sevin does not penetrate food items; neither does it build up in the environment.

¹ University of South Australia - "Bhopal, the World's Worst Industrial Disaster"

References and Resources:

Oregon State University - National Pesticide Information Center - Carbaryl

Molecular Expressions - Carbaryl