Cross-contamination in pesticide applications is best described as:

• A. The unintended transfer of residues to non-target areas.
• B. A term for accidental mixing of two pesticides on the same day.
• C. Pesticide shelf life.
• D. Cross-contamination occurs only during irrigation.

Answer: (C)

Cross-contamination means residues from a pesticide application end up where they weren’t intended—non-target areas such as nearby crops, water sources, soil, or even equipment and clothing. This can happen through spray drift carried by the air, residues left on sprayers or PPE that are then transferred to other sites, or contaminated wash water and containers. It’s about unintended transfer of residues, not about how long a product lasts, not about mixing different products on the same day, and not something limited to irrigation events. To prevent it, clean and rinse equipment thoroughly between uses, calibrate the sprayer to apply labeled rates, use dedicated equipment when possible, implement drift-reduction practices, and follow proper storage and handling procedures.