Etofenprox, the mosquito-killing pesticide that Allegheny County sprayed along roadways this summer to combat the spread of West Nile virus, is widely used and considered safe by many municipalities. That doesn't mean it comes with no warnings.
Here are the precautions on the material safety data sheet for Zenivex E20, the trade name for etofenprox:
• Hazardous to humans and domestic animals.
• Harmful if swallowed.
• Causes moderate eye irritation.
• Avoid contact with eyes, skin, or clothing.
• Wash thoroughly with soap and water after handling and before eating, drinking, chewing gum, using tobacco, or using the toilet.
• Remove contaminated clothing and launder before reuse.
• Repeated exposure to etofenprox can cause skin irritation.
Zenivex E20 is not regulated by the Occupational Safety and Health Administration, the data sheet says. It is not a carcinogen, has no adverse effects on reproduction and does not cause mutations. It is, however, toxic to aquatic organisms, including fish and invertebrates. It's also toxic to bees exposed to direct treatment.
No pesticide is risk-free, according to the Pennsylvania Department of Health, and adverse health effects depend on the concentration and duration of exposure.
Guillermo Cole, Allegheny County Health Department spokesman, said the county uses a low volume -- 1 to 3 ounces per acre, applied with a ultra-low volume sprayer -- and that the spray is regarded as harmless to people and pets.
"We do residential streets and neighborhoods, and there's never been a notice for people to stay indoors during the spraying," he said. "I don't think it's considered necessary."
He said the county keeps spraying until the first frost -- which has reportedly occurred this month in most parts of the region.
Sally Kalson: firstname.lastname@example.org or 412-263-1610.