Laundry study to keep pesticide applicators clean and safe

Carol Black cares about work-place safety. That’s especially true in her job as a pesticide education specialist at Washington State University.

Portrait photos of Carol Black. She's wearing a dragonfly brooch on a red sweater.
Carol Black

To keep workers safe, she and several colleagues are evaluating laundering practices on the clothing worn by professional pesticide applicators.

“We have over 24,000 licensed pesticide applicators in Washington, and the first line of protections, and most common garments, are long sleeve shirts and long pants,” Black said.

But nobody is sure that modern washing machines and current laundering techniques are keeping applicators safe from modern sprays, especially when worn over and over. So Black is working with other pesticide and textile specialists in Maryland, Brazil, and France to update laundering procedures that were last researched in the 1980s.

“A lot has changed in the past 30-plus years,” Black said. “Pesticides, including herbicides and insecticides, are different and less toxic. Clothes are made from newer fabrics and blends. And people’s laundry habits have changed.”

Pesticides include any substance used to kill, repel, or control certain forms of plant or animal life considered to be pests, according to the National Institutes of Health.

She said the earlier best practices relied on washing with hot water and using detergent that included phosphates. Now, most people wash with warm water and detergents don’t have those additives anymore. Plus, nobody knows if high-efficiency washers that use less water make a difference.

This summer, Black will work with licensed noxious weed managers who apply using back-pack sprayers. The volunteers will wear pants sewn in Brazil to correlate with other studies. The clothes will be worn and laundered throughout the spray season following their normal routine.

At the end of the spray season, Black will collect the clothes, evaluate the amount of wear, and analyze them for remaining pesticide residues.

Pesticide residue can bind to clothing, Black said, but that’s normally not a concern. The concern is if the residue becomes dislodged by things like sweat, releasing residues from the fabric and getting on the skin of the applicator. The study will evaluate water rinse, artificial sweat rinse, and solvent extraction for comparisons.

Black said she doesn’t anticipate any concerns, but true safety requires updating best management practices that are three decades old.

Standard cotton/polyester clothing will be evaluated this year.  Next year, she plans to evaluate clothing made with repellent finish since laundering habits impact the quality of the finish.