Originally written by Gared Shaffer, former SDSU Extension Weeds Field Specialist.
Crop damage could occur if sprayer clean-out is overlooked or not properly conducted. It is critical to always follow the procedure specified on the herbicide or commercial cleaner label to completely remove herbicide residue from the sprayer system. The following guidelines are general sprayer clean out procedures, but the best source of information is the specific herbicide label of the product and the operator’s manual of the sprayer. Most common tank cleaning solutions include water, commercial tank cleaner, ammonia, bleach, detergents, petroleum products (diesel or kerosene) or non-ionic surfactant.
General Cleaning Recommendations for Sprayer Equipment
- Make sure spray tank is empty before leaving the field or dispose of spray solution according to label.
- Always clean the sprayer in an area that will ensure no contamination of water supplies, streams, crops or other sensitive areas and away from contact with humans, pets and livestock.
- Rinse equipment thoroughly removing any visible product adhering inside of tank. Fill the tank 10% with water and the herbicide-specific suggested first solution. Agitate for 15 minutes.
- Flush first rinse through hoses, boom and nozzles for 15 minutes, then drain.
- After flushing system, disassemble, clean and flush all strainers, filters, nozzles, nozzle screens, diaphragms and boom ends where residue can accumulate. Reassemble sprayer parts.
- Fill the tank 10% with water and the second rinse solution (if applicable) while agitating. Charge booms. Let it sit preferably overnight before flushing again.
- Continue listed recommended rinses from herbicide and commercial cleaner labels by filling, agitating and flushing the system with the suggested solution each time. Could be necessary to rinse tank three more times for some herbicide products.
- Thoroughly clean the outside of equipment including tanks, booms, nozzles and tires.
