Pesticide Safety and Human Health
How toxicity is communicated
Signal words come from acute toxicity categories: DANGER (Category I, with DANGER-POISON and a skull and crossbones when oral LD50 is 50 mg/kg or less or dermal LD50 is 200 mg/kg or less), WARNING (Category II), and CAUTION (III and IV). LD50 is the dose that kills half a test population, so a lower number means a more toxic product. Units are milligrams per kilogram of body weight, meaning a 70 kg adult and a 10 kg child reach a toxic dose at very different amounts.
Exposure routes and PPE
For applicators the dermal route dominates, followed by inhalation and oral. Label PPE is a minimum: chemical-resistant gloves (not leather or cloth), long sleeves and pants, boots, eyewear, and a respirator where specified. Fit-test respirators, change cartridges on schedule, and never store PPE with pesticides.
Florida heat
Heat illness is a real hazard and its early signs (headache, nausea, dizziness, confusion) mimic pesticide poisoning. The classic trap is blaming the flu or the chemical. Move the person to shade, cool them, and hydrate; do not send a symptomatic worker back into PPE.
Poisoning and first aid
Cholinesterase-inhibiting insecticides (organophosphates and carbamates) cause salivation, lacrimation, urination, diarrhea, and pinpoint pupils. Keep the national Poison Control number, 1-800-222-1222. First aid: remove contaminated clothing, wash skin with soap and water, flush eyes for 15 minutes, and take the label to the medical provider. Never induce vomiting unless the label directs it.
Worked example
A product with an oral LD50 of 40 mg/kg carries DANGER-POISON. For a 70 kg applicator, the lethal dose is about 40 x 70 = 2,800 mg, or 2.8 g, which is why a single splash into an open cut matters.