Which statement about pesticide equipment cleanup is false?

• A. Sprayers should be thoroughly rinsed with water detergent solution for several minutes.
• B. When getting ready to store your sprayer, add some lightweight oil in the tank before final flushing.
• C. Leftover pesticide residue in the spray tank is permitted when changing products.
• D. Rinse water should be used to flush the system until all residues are removed.

Answer: (C)

Cleaning pesticide equipment thoroughly is about preventing cross-contamination between products. You must remove all pesticide residues from the tank and system before storing or switching to another product. Leaving any residue is not acceptable because it can mix with the next product, causing crop injury, regulatory issues, or ineffective applications. The proper approach is to rinse the sprayer with water and a detergent solution for several minutes, circulate and scrub through the entire system, then rinse with clean water until no residues remain. The rinse water should be used to flush the system until residues are removed, and the equipment should be stored empty and dry after the final rinse. Some guidelines note adding a small amount of lightweight oil to the pump before storage to protect moving parts, but this oil should be flushed out as part of the final cleanup so it doesn’t contaminate future applications.