Pesticide Labels, Formulations, and Mixing/Loading
What the label must tell you
Every label carries the brand and common name, active and inert ingredient percentages, EPA registration number, establishment number, formulation abbreviation, signal word, precautionary statements, PPE, first aid, environmental hazards, storage and disposal, and the directions for use: sites, target pests, rates, application methods, restricted-entry interval (REI) and preharvest interval (PHI). Supplemental and 24(c) SLN labels must be present and followed; they modify, they do not replace, the base label.
Formulations and their handling quirks
- EC (emulsifiable concentrate): solvent-based; can damage rubber and plastic, may cause phytotoxicity, needs an emulsifier.
- WP (wettable powder): suspension, abrasive, heavy agitation, visible residue.
- WDG/DF (dry flowable): low dust, easy measuring, still needs agitation.
- SC/flowable: liquid suspension, needs agitation.
- SL (solution): true solution, minimal agitation.
- G (granular), bait, dust, microencapsulated (slow release - higher bee hazard), and RTU products.
Mixing and loading
Do a jar test before any unfamiliar tank mix. Fill the tank half full of water, start agitation, then add products in WALES order: Wettable powders, Agglomerates/water-dispersible granules, Liquids/flowables, Emulsifiable concentrates, Solutions - then adjuvants last. Keep agitation running, never mix more than you will apply, and use an air gap or backflow preventer so the fill hose never sits in the tank or in a well. Triple-rinse and puncture containers.
Trap: confusing REI (when people may re-enter) with PHI (when crops may be harvested), and assuming two products with the same active ingredient can be stacked "for extra control."
Rule of thumb: the labeled rate range is a legal range, not a suggestion - read and follow it, and never exceed it.