9.3 Container Rinsing, Rinsate Handling & Equipment Cleanup

Container Rinsing, Rinsate Handling & Equipment Cleanup

Core Principle: An empty pesticide container is not empty. Roughly 1 to 5 percent of the original contents clings to the walls as film, and in a 2.5-gallon jug of concentrate that residue can be more active ingredient than a homeowner would use in a decade. What you do in the sixty seconds after the last pour determines whether that container is hazardous waste or recyclable plastic.

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Rinse Immediately — Timing Is the Whole Trick

Rinse at the time of emptying, while the residue is still wet and mobile. A jug set aside "to deal with later" bakes in Arizona heat; the film dries, cross-links and bonds to the plastic, and no number of later rinses will remove it. A dried container remains a regulated waste and cannot be recycled.

Triple Rinsing

1. Empty the container into the spray tank and let it drain for 10 seconds after the flow becomes drips.
2. Fill the container one-quarter full with clean water.
3. Replace the cap and shake vigorously for 30 seconds, rotating so water contacts every interior surface, including the handle void and the shoulder.
4. Pour the rinsate into the spray tank and drain for 10 to 30 seconds.
5. Repeat steps 2 through 4 twice more — three complete cycles in total.

Pressure Rinsing

A pressure-rinse nozzle punched through the base of the container is faster, uses less water and generally removes more residue. Insert the probe, and rinse at approximately 40 psi or greater — commonly around 60 psi — for at least 30 seconds, directing the spray around the interior while the rinsate drains into the tank. Pressure rinsing has the useful side effect of puncturing the container in the same motion.

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Rinsate Is a Pesticide

This is the point candidates most often get wrong. Rinsate is diluted pesticide, and it is subject to the same label as the product it came from.

A dedicated rinsate storage tank is good practice on any operation running repeat loads of the same product. Label it clearly with the product and date; using the wrong rinsate as make-up water is a fast route to crop injury.

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Regulatory Status Under RCRA

An unrinsed container holding concentrate residue is hazardous waste. Depending on the active ingredient it may be a P-listed acute hazardous waste or a U-listed toxic waste, with the storage, manifesting and disposal duties that follow.

Complete triple rinsing or pressure rinsing decontaminates the container. Once decontaminated and punctured so it cannot be reused, it becomes ordinary non-hazardous solid waste and may be:

• Recycled through the Agricultural Container Recycling Council (ACRC) collection programme, which accepts clean, dry, punctured HDPE containers with caps and booklets removed; or
• Disposed of in a sanitary landfill, where local rules permit.

Never burn pesticide containers, never bury them, and never reuse a container for any purpose whatever.

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Cleaning the Application Equipment

Tank cleanout protects the next customer.

• Where to clean. On the mix/load pad, with the same water-protection distances that governed loading. Wash water is rinsate.
• Sequence. Drain the tank fully onto the treated site, then rinse the tank, boom and lines with clean water and spray that rinse out on the labeled site. Repeat. Scrub the tank interior if a wettable powder or flowable was used.
• Cleaning agents. Some labels prescribe a specific cleaner — household ammonia, a commercial tank cleaner, or a chlorine-based rinse. Follow it. Never mix a chlorine cleaner with an ammonia cleaner; the reaction produces toxic gas.
• Screens and nozzles. Remove suction, in-line and tip screens and clean them separately with a soft brush. Never clear a nozzle with your mouth or with a wire — a wire deforms the orifice and destroys the spray pattern.
• Sulfonylurea and growth-regulator carryover. These chemistries injure sensitive crops at extraordinarily low residues. If the sprayer will next treat cotton, grapes, melons or ornamentals after a hormonal herbicide, an ordinary water rinse is not enough — follow the label’s cleanout procedure precisely, and where the operation can support it, dedicate a separate sprayer to hormonal herbicides.

Exam Trap: "Dispose of the rinsate properly" is not a synonym for "find a drain." In every certification exam the correct disposal of rinsate is application to a labeled site at labeled rate.