How long should dichlorvos be left on hair to kill lice? - briefly
Leave the solution on the scalp for approximately 10 minutes before rinsing thoroughly. This exposure time is sufficient to eliminate head‑lice infestations.
How long should dichlorvos be left on hair to kill lice? - in detail
The exposure period required for dichlorvos to be effective against head‑lice is limited to a few minutes. Manufacturer data and regulatory guidance specify a contact time of 10 ± 2 minutes before rinsing. Extending the interval beyond this window does not increase mortality and raises the risk of systemic toxicity.
Key points for proper use:
- Apply the solution to dry hair, ensuring full coverage of the scalp and shafts.
- Maintain the product on the hair for 10 minutes; a timer is advisable.
- Rinse thoroughly with lukewarm water and a mild shampoo.
- Repeat the treatment after 7–10 days to eliminate any newly hatched nymphs.
- Use protective gloves and avoid inhalation; work in a well‑ventilated area.
- Do not exceed the recommended duration; prolonged exposure can cause cholinergic symptoms such as headache, nausea, muscle twitching, or respiratory distress.
Safety considerations:
- Dichlorvos is an organophosphate; it is not approved for routine scalp application in many jurisdictions.
- Children, pregnant women, and individuals with respiratory conditions should not be treated with this agent.
- In case of accidental ingestion or prolonged skin contact, seek immediate medical attention and provide the product label to healthcare providers.
Alternative options with lower toxicity include permethrin 1 % lotion, ivermectin oral therapy, or silicone‑based lice‑removal devices. These alternatives avoid the systemic risks associated with organophosphate exposure while offering comparable efficacy when applied according to label instructions.