Cardboard Charlie is all geared up in his PPE wear.
PPE is critical to ensuring safe handling of pesticides.

Pesticide mixers/loaders risk dangerous exposure since they work with concentrated (non-diluted) pesticide products.

Proper PPE

Before opening any pesticide container, by law, you must be wearing the appropriate personal protective equipment (PPE) specified on the pesticide label. Labels give minimum PPE requirements, but consider wearing additional PPE for increased face and torso safety. If splashing can occur, or when leaning across potentially contaminated equipment during a mix/load task, wear a bib-top apron made of butyl, nitrile, or foil-laminate material, preferably with built-in gloves and sleeves.

Liquid pesticides splash, dry pesticides emit dusts, and both can release invisible vapors dangerous to your body. Face shields help prevent splashes or dusts from directly contacting your face. When mix/load tasks include dangers of dust or vapors, use NIOSH/MSHA-approved dust/mist or vapor-removing respirators with tight-fit goggles or shielded safety glasses.

Mixing And Loading

Choose a well-ventilated (preferably outdoors) area for mix/load tasks away from unprotected people, animals, foods, and stored pesticides. Use a sharp pesticide-dedicated knife to open paper-based pesticide containers (don’t rip) and wash the knife immediately after use.

When pouring pesticides, keep containers and mix/load activities below face level and position yourself with your back to the breeze/wind. Prevent accidental spills by closing pesticide containers after each use. Never leave a tank unattended when filling with the label-required diluent (water, kerosene, high-grade oil, etc.). To prevent back-siphoning contamination, keep water sources (hoses, pipes) above the pesticide solution. If pumping, use a check-valve, anti-siphoning device, or backflow preventer. If you are splashed by pesticide, immediately remove contaminated clothing and wash with soap and water.

Making Mixtures

Combining different pesticides into a single mixture may be desirable for increased application efficiency. Pesticide labels will indicate illegal mixtures and may provide compatibility charts for known effective mixtures. Beyond that, mixtures are trial-and-error efforts since combining different chemistries can produce incompatibility. Mixtures that “look good” may contain compromised chemistries that reduce active ingredient effectiveness, cause unforeseen toxicity risks to mix/load/applicator personnel, or result in unintended damage to equipment and/or the target site.

Do a compatibility test before making a large-volume mixture. Wear the combined PPE dictated by all product labels involved in the mixture. Consider added safety by wearing a face shield, protective eyewear, chemical-resistant gloves, and a foil-laminate apron. Use a large, clean, clear glass container. Add diluents and pesticide products in the same proportion as intended for the larger tank mix. Unless the label states otherwise, use the W-A-L-E compatibility method:

• Add some diluents
• Add wettables (and other powders) and water-dispersible granules
• Agitate, then add remaining diluents
• Add all liquid products (solutions, surfactants, adjuvants, flowables) and mix
• Add emulsifiable concentrates last

Shake well, if capped, or vent to avoid vapor buildup. Check for heat (sign of unknown chemical reactions that might compromise pesticide efficacies) over a 15-minute period. The mixture is incompatible if scums, lumps, precipitates, gels, or excessive heat form. Don’t confuse settling of wettable powders with precipitates. If the mixture appears compatible, test-apply the sample to the target area before making larger mix volumes.

Clean Up

First, clean your equipment, then wash the exterior of gloves, arm/leg cuffs, and other obviously contaminated clothing before taking them off. Discard according to the label or seal clothing in a plastic bag until it can be washed (never with family laundry; run an empty wash cycle between loads). Immediately wash face, arms, and hands with warm water and mild detergent, and do a full-body wash as soon as possible (no later than the end of the day).

Secure all pesticides and properly dispose of pesticide-related articles (empty containers, contaminated PPE). Co-workers can clean contaminated equipment only if they have received appropriate safety training and wear the full PPE required by the label(s) for handlers, including a chemical-resistant apron. Do not “store” unused pesticide mixtures in application equipment, which can cause corrosion, clogged nozzles, reduced active ingredient efficacies, and product separations. Collect equipment rinsates and dispose of properly, preferably at a target site.

Record Keeping

Consistently document your pesticide use to show proof of correct handling and usage. Records help you save money by documenting effective and ineffective applications, and can help you develop cost-effective inventory management. At a bare minimum, records should include:

• Name of handlers and applicants
• Date and time of day of mixing and application
• Location/description of target site and weather conditions at application time
• Target surface (crop, animal, structure)
• Target pest
• Equipment used
• Pesticides used (include brand name, common name, formulation type, percentage of active ingredient, EPA registration number)
• Amount of pesticide mixed, adjuvants, diluents volumes
• Total pesticide amount applied
• Application rate and size of treated area
• Comments (any useful observations)