5.4 Storage and Disposal of Pesticides and Containers

Container Rinsing: Triple-Rinse and Pressure-Rinse

An empty pesticide container is not truly empty until it has been rinsed. Residue left in the container is pesticide that you paid for, that you are legally responsible for, and that can contaminate water or injure people if it leaks. Two methods are accepted:

Triple-Rinsing

1. Empty the container into the spray tank and let it drain for an additional 30 seconds.
2. Add rinse water equal to about 20% of the container's volume.
3. Replace the cap and shake vigorously for 30 seconds so rinse water contacts every interior surface.
4. Pour the rinsate into the spray tank; let drain 30 seconds.
5. Repeat steps 2-4 two more times (three rinses total).
6. Puncture the container so it cannot be reused.

Pressure-Rinsing

A pressure-rinsing nozzle (a hollow probe with angled jets) is inserted through the bottom of the container after draining. Water under pressure sprays the interior for the time specified by the nozzle manufacturer (typically 30-60 seconds), and the rinsate drains into the spray tank. Pressure-rinsing is faster and often more consistent than triple-rinsing.

Rinsate Disposal

Rinsate from triple-rinsing or pressure-rinsing goes into the spray tank and is applied to a labeled site at or below the label rate. Never pour rinsate down a drain, into a ditch, or onto the ground.

Empty Container Handling and Recycling

After rinsing and puncturing, empty containers should be:

• Recycled through the Ag Container Recycling Council (ACRC) program or a participating Iowa ag retailer. ACRC contractors grind and process the plastic for use in industrial products.
• Disposed of in a permitted landfill only if recycling is not available and the label allows it. Many Iowa landfills will not accept unrinsed or unpunctured containers.
• Never burned or buried on the farm. Open burning of pesticide containers is illegal under Iowa and federal air rules and can release toxic dioxins or hydrogen chloride.

Paper and fiber containers should be completely emptied, rinsed if possible, and disposed of according to the label - often at a permitted landfill or incinerator.

Storage Requirements

Proper storage protects people, livestock, and the environment. Iowa adopts federal storage guidance through the pesticide label and Iowa Department of Agriculture and Land Stewardship (IDALS) rules. Key requirements and best practices:

• Locked and posted - storage buildings must be locked and marked with a warning sign (e.g., "Pesticides - Keep Out").
• Ventilated - mechanical or natural ventilation prevents vapor buildup.
• Temperature-controlled - keep products above freezing and below the label's maximum storage temperature; extreme heat can pressure-pack liquid containers.
• Separate - store pesticides away from feeds, fertilizers, seed, and water sources to prevent cross-contamination.
• Original labeled containers - never transfer pesticides to food or beverage containers; keep the EPA registration number and signal word visible.
• Secondary containment - liquid pesticide storage areas should have a curb or basin capable of holding spills.
• Dry and well-lit - moisture damages paper and fiber containers; good lighting helps applicators read labels.
• Inventory - keep a current inventory and SDS binder for emergency responders.

Bulk and Mini-Bulk Tanks

Bulk tanks (large stationary or nurse-tank volumes) and mini-bulk tanks (typically 110-300 gallon returnable containers) require additional safeguards:

• Secondary containment under IAC 21—44.7: for nonmobile bulk liquid storage located outside an enclosed structure, a volume sufficient to hold at least 110% of the capacity of the largest single container plus the space occupied by other tanks in the containment structure; inside an enclosed structure, at least 100% of the largest single container plus the space occupied by other tanks. Nonmobile bulk dry storage instead needs a minimum six-inch curb set at least three feet horizontally from the storage vessel.
• Dikes and pads made of impermeable material (concrete or synthetic liner) compatible with the stored product.
• Valves and hoses inspected regularly; shut-off valves at the tank and at the receiving vessel prevent spills during transfer.
• Labels and placards on each tank identifying the contents and emergency contacts.
• Locking valves when the tank is unattended.

Unusable Pesticide and Hazardous Waste

A pesticide becomes unusable when it is banned, expired, contaminated, off-spec, or no longer wanted. Under federal RCRA rules and Iowa DNR hazardous-waste rules, an unusable pesticide may be a hazardous waste if it is:

• Listed as a hazardous waste (some older pesticides such as certain arsenicals, organochlorines, and dioxin-contaminated products).
• Characteristic - ignitable, corrosive, reactive, or toxic under the TCLP (Toxicity Characteristic Leaching Procedure) test.

Unusable pesticide must be disposed of through a licensed hazardous-waste hauler at a permitted facility. Do not burn, bury, or dump any pesticide. Iowa periodically operates Clean Sweep collection programs for agricultural pesticides through IDALS and Iowa DNR; these programs accept cancelled or unusable products at no cost to the applicator in many cases.

Practical Storage and Disposal Checklist

• Triple-rinse or pressure-rinse every container; add rinsate to the spray tank.
• Puncture empty containers before recycling or disposal.
• Recycle containers through ACRC or a participating retailer.
• Store pesticides locked, ventilated, and away from feeds, fertilizers, and water.
• Keep products in original labeled containers.
• Size secondary containment for bulk and mini-bulk tanks to 110% of the largest container.
• Never burn or bury pesticides or containers.
• Use Iowa Clean Sweep collections for unusable product.