Hoarding Chemicals Eventually Costs More Than It Saves

Despite all the talk and the growing use of alternatives to toxicants in IPM programs, the use of toxicants is still a major player in the battle against structural pests. In the PCO's applications to areas likely to be infested, the residual life of the treatment is an important consideration. A longer residual value can mean fewer callbacks.

Costly, exhaustive tests are required to establish efficacy to satisfy the U.S. Environmental Protection Agency's strict standards. According to Sam Creeger, president of the Environmental Chemistry Institute in Pittsburgh and formerly with the EPA for 12 years, the stability of the product's chemistry is an important requirement for registration. The unopened product on a PCO's shelf must keep its integrity for at least two years, even after being exposed to temperature extremes. If it freezes and separates, the product must remain intact after being warmed and shaken vigorously. Among the symptoms of degraded pesticides are powders that are caked or lumpy, emulsion concentrates that don't turn milky white when diluted, and sludge at the bottom of the container.

If any of the concentrate's components the active ingredients, the inerts/solvent/emulsifier, or other additives are affected by extremes of temperature or aging beyond two years, the residual value of the treatment is compromised.

More sensitive to the aging than liquid concentrates is the aging of baits for rodents or insects. Foodstuff attractants are especially vulnerable to rapid degradation. Dr. Bill Jackson of Bowling Green State University in Bowling Green, Ohio, told me of an experiment in which rats were offered a choice of a fresh bait and the same bait that had been frozen for six months. They ate the fresh bait. Considering the availability of relatively fresh and nutritious waste food, how can we expect a rodent to prefer second-grade food?

With ants being so finicky about the choice of baits freshly made by researchers, we should not be surprised if they throw up their antennae and pass by the bait stations that we deploy to attract them in the field.

WHY WE DO IT. The use of old stocks by PCOs is natural. Old-timers with the Great Depression mentality can't bear to throw anything away. Others, while not concerned about wasting resources, sometimes buy excessive stocks to get a lower unit price. Occasionally, an acquisition includes an old stock of pesticides. Of course, this must be used up. If any of the packages were opened, the decomposition of the product is greatly accelerated.

Pest control operators with stocks of cans of aerosols should shake the cans occasionally to reduce the possibility of clogging the nozzle. Also, aerosols sometimes gradually lose some of their propellant over time so that the contents cannot be completely emptied. This is unfortunate, because the contents may still be good. (Heed the manufacturers' warning: "Rotate Stock!")

Among the few products that may not be affected are desiccant and borate powders. But even these can give lower performance if they are stored in cold weather or in highly humid environments for long periods of time. Condensation on dust particles can clog application nozzles or reduce their efficiency by reducing thrust. I have observed almost twice the reach of the dust in a basement steampipe tunnel after the product was set on a moderately warm radiator overnight.

OTHERS WHO HOARD. Another form of hoarding may be of interest to PCOs. Sam Creeger reported on a situation in which fleas were found infesting a dog that had just been returned from a dip treatment by a veterinarian. Creeger investigated and found that the same dip was used for many treatments over a period of several days. Apparently the toxicant was degraded with animal secretions, bacteria and other organic contaminants and had little toxic value. If this type of occurrence is commonplace, PCOs should be aware of this as a possible reason for recalls, even for flea jobs that have been done properly.

Two credible sources with much experience confirmed Creeger's opinion and told me it was a common occurrence to find pets reinfested with fleas on the same day they were returned from a dip treatment by a veterinarian. Those two sources are Bob Wright, a veteran PCO with Wrightway Termite and Pest Control, Fort Lauderdale, Fla., and Kenneth Knapp, regional inspector for the Florida Department of Agriculture, South Broward, Fla.

Many years ago I wrote that pest control operators should treat homes for fleas, and veterinarians should treat pets for fleas. Perhaps that's a Myth Conception if veterinarians or pet groomers who dunk pets in a flea-killing tub are also chemical hoarders.

It is a Myth Conception that a stock of pesticides has an eternal life. Weakening the product's performance or effectiveness by hoarding the supply to save money will only waste money with more callbacks.