3.5 Safe Handling and Storage

Storage Facility Requirements

Iowa Administrative Code (Chapter 21-44) and the Iowa Core Manual (CS445) set clear storage standards. A pesticide storage facility must be:

• Locked and secure to prevent access by children, livestock, and unauthorized people.
• Ventilated - mechanical or natural ventilation that exhausts to the outside, so vapor concentrations stay below hazardous levels.
• Dry and temperature-controlled - most labels specify a storage temperature range; freezing can break emulsions and heat can pressurize containers or degrade the active ingredient.
• Separate from feed, seed, fertilizer, food, and food-handling equipment to prevent cross-contamination.
• Floored with an impermeable surface (concrete sealed with chemical-resistant coating) so spills can be contained and cleaned.
• Posted with warning signs at entrances.

Iowa Bulk Storage Rules

Iowa Administrative Code 21-44.7 requires secondary containment for nonmobile bulk pesticide storage (bulk = undivided quantities greater than 55 gallons liquid or 100 pounds dry). Outdoors, containment must hold at least 110 percent of the capacity of the largest container plus space for other tanks; inside an enclosed structure, at least 100 percent. New permanent storage sites must be at least 400 feet from public water supply wells and 150 feet from private wells. Bulk containers must have locking devices, and all valves must be closed and locked when the facility is unattended. Discharges into secondary containment must be recovered promptly, and spills must be reported to the Iowa DNR, county sheriff, or local police within 6 hours of discovery.

Container Rules

• Keep pesticides in their original labeled containers. The label is the legal document; an unlabeled container is a violation.
• Never transfer pesticides to food or beverage containers. A child or coworker who drinks from a soda bottle containing paraquat can die within hours. This single mistake is one of the most common and most fatal pesticide accidents.
• If you must transfer to a service container for same-day use, label it with the product name, EPA registration number, signal word, and the date.

Inventory and Records

Maintain a current inventory that lists each product, the EPA registration number, the quantity on hand, and the date received. Rotate stock so the oldest product is used first (first in, first out). Keep the inventory accessible but stored away from the pesticides themselves so it survives a fire or spill. Iowa commercial applicators must also keep application records for each job, including the site, product, rate, date, and REI.

Mixing and Loading Precautions

The mixing and loading step is the highest-exposure moment in the application process because the applicator handles concentrate.

• Work outdoors or in a well-ventilated area unless the label requires a closed system.
• Stand upwind of the container and the spray tank.
• Use a closed mixing system when the label allows it, especially for Category I products.
• Wear all label PPE plus a chemical-resistant apron for pouring.
• Do not leave the sprayer unattended while filling.
• Measure carefully using dedicated measuring equipment, not household cups.

Preventing Back-Siphoning

Back-siphoning occurs when a drop in water main pressure pulls pesticide-contaminated water back into the well or public supply. It is a serious public-health risk and a clear violation.

To prevent back-siphoning:

• Maintain an air gap of at least twice the diameter of the supply pipe (or 6 inches, whichever is greater) between the end of the fill hose and the highest possible water level in the spray tank.
• Install an anti-backflow device (check valve) on the water supply line when an air gap is not feasible.
• Never put the fill hose below the surface of the spray solution.
• Never leave a hose connected to a faucet with the other end in the tank.

Spill Response

Keep a spill kit in the storage area and on the spray rig. A basic kit contains:

• Absorbent material (cat litter, vermiculite, or commercial pads)
• A non-sparking shovel and a sturdy broom
• Chemical-resistant gloves, apron, and boots
• Goggles or a face shield
• Heavy-duty plastic bags or a labeled drum for collected waste
• The product label and SDS

If a spill occurs:

1. Protect yourself - put on PPE before approaching.
2. Contain the spill - dike with absorbent to keep it out of drains, waterways, and sewers.
3. Absorb - cover the spill with absorbent and sweep it up.
4. Decontaminate the surface with the solvent or cleaner the SDS recommends, then absorb again.
5. Package the waste in a labeled, sealed container and dispose of it as hazardous waste; do not put it in regular trash.
6. Report large spills to IDALS and, if the spill reaches a waterway, to the National Response Center at 1-800-424-8802.

Fire and Leak Preparedness

• Store a fire extinguisher rated for chemical fires (dry chemical or CO2) at the storage entrance and inspect it annually.
• Inform the local fire department of the pesticide inventory location and hazards so responders can plan.
• Keep absorbent and containment booms ready to capture leaks from damaged drums.
• If a container leaks, transfer the product to a sound, labeled service container and clean the original area.
• Never store pesticides near ignition sources, and never burn pesticide containers unless the label specifically permits it; burning can release toxic smoke.

Post-Application Safety

After the application is complete, safety work continues:

• Observe the REI and keep people and animals out of the treated area until it expires.
• Post warning signs where the label or WPS requires and remove or cover them when the REI ends.
• Clean the equipment in a dedicated wash pad; never rinse into a storm drain or surface water.
• Wash PPE separately from family laundry, using hot water and detergent, and run an empty cycle afterward.
• Shower and change clothes before eating, drinking, smoking, or going home; keep contaminated work clothes separate from the household.
• Record the application - product, EPA registration number, rate, site, date, REI, and weather conditions.

Disposal Basics

• Empty containers must be triple-rinsed (or pressure-rinsed) before disposal or recycling; the rinseate goes into the spray tank.
• Never burn pesticide containers unless the label specifically permits it; burning can release toxic smoke.
• Follow Iowa hazardous-waste rules for unwanted concentrate, banned products, and contaminated absorbent.
• Use the Iowa Pesticide Container Recycling Program where available for triple-rinsed HDPE containers.

Safe handling and storage protect you, your family, your employees, and Iowa's groundwater. Treat every container as if it could leak, and every step as if the inspector were watching - because one day, they will be.