How long should tar soap be left on for lice? - briefly
Tar soap should stay on the scalp for «10–15 minutes» before rinsing. A second application after «7–10 days» helps eliminate any newly hatched lice.
How long should tar soap be left on for lice? - in detail
Tar‑based soap acts as a neurotoxic agent that disrupts lice metabolism. The product must remain on the scalp long enough for the active compounds to penetrate the exoskeleton but short enough to prevent excessive skin irritation.
Typical guidance recommends a contact period of 10 to 15 minutes. For infestations with known resistance, extending the exposure to 20–30 minutes may improve efficacy, provided the scalp shows no adverse reaction. Exceeding 45 minutes increases the risk of dermatitis and should be avoided.
Practical protocol:
- Apply a generous layer of «tar soap» to dry hair, ensuring coverage of the entire scalp and hair shafts.
- Massage gently for 30 seconds to distribute the formulation evenly.
- Allow the product to remain for the chosen duration (10–30 minutes), monitoring for redness or itching.
- Rinse thoroughly with lukewarm water; avoid hot water that could open pores and increase absorption.
- Comb hair with a fine‑toothed lice comb immediately after rinsing to remove dead insects and eggs.
- Repeat the treatment after 7 days to target newly hatched nymphs.
Safety considerations:
- Do not apply to broken skin, eyes, or mucous membranes.
- For children under 2 years, seek medical advice before use.
- Discontinue if severe irritation or allergic response occurs; wash scalp immediately and consult a healthcare professional.