How much dichlorvos is needed for lice? - briefly
A 0.1 % dichlorvos solution applied at about 0.5 mL per 100 g of hair (roughly 5 mL for an adult) provides the standard effective dose for lice control.
How much dichlorvos is needed for lice? - in detail
Dichlorvos, an organophosphate insecticide, is applied to lice infestations as a liquid concentrate that must be diluted before use. The standard preparation for human treatment is a 0.5 % solution, achieved by mixing 5 mL of the 100 % concentrate with 995 mL of water. For a single head, the recommended volume is 10 mL of the diluted mixture, applied evenly to the scalp and hair, ensuring contact with all lice and nits. The solution should remain on the hair for 10 minutes before rinsing with water; repeat the procedure after 7 days to eliminate newly hatched insects.
Key points for safe and effective use:
- Prepare the dilution in a clean container; never apply the concentrate directly.
- Use a calibrated dropper or spray bottle to measure 10 mL accurately.
- Apply to dry hair; avoid contact with eyes, mucous membranes, and broken skin.
- Wear disposable gloves during application; wash hands thoroughly afterward.
- Keep children and pets away from the treated area until the hair is rinsed and dried.
- Store the concentrate in a locked, child‑proof cabinet, away from food and drink.
Toxicity considerations demand strict adherence to the dosage. Ingesting or inhaling the undiluted product can cause cholinergic poisoning, characterized by muscle weakness, excessive salivation, and respiratory distress. If accidental exposure occurs, seek immediate medical attention and provide the product label for reference.
For individuals with known hypersensitivity to organophosphates, or for pregnant and nursing persons, alternative treatments such as permethrin 1 % lotion or ivermectin oral therapy should be considered, as they present lower systemic risk.