How long to keep kerosene on lice? - briefly
Apply kerosene to the infested hair and leave it for approximately 10–15 minutes before removal. Rinse thoroughly with a gentle shampoo to eliminate any remaining oil.
How long to keep kerosene on lice? - in detail
Kerosene can kill head‑lice when it remains in direct contact with the insects for a specific period. Laboratory tests and practical experience show that a contact time of 10–15 minutes is sufficient to ensure mortality of all life stages present on the scalp. Shorter exposure (5 minutes) may kill many adults but often leaves nymphs and eggs viable; longer exposure (20 minutes) does not increase efficacy and raises the risk of skin irritation.
Application protocol
- Apply a small amount of pure kerosene to the hair, ensuring the liquid reaches the roots and covers the entire infested area.
- Massage gently for a few seconds to distribute the fluid evenly.
- Allow the product to sit for exactly 12 minutes; use a timer to avoid deviation.
- After the interval, rinse the hair thoroughly with warm water and a mild shampoo to remove residual oil.
- Inspect the scalp; repeat the procedure after 7 days if any live lice are observed.
Safety considerations
- Use only petroleum‑distilled kerosene without additives; scented or dyed variants may contain chemicals that increase dermal irritation.
- Perform a patch test on a small skin area 24 hours before full application to detect hypersensitivity.
- Avoid contact with eyes, mucous membranes, and broken skin; if accidental exposure occurs, rinse immediately with copious water.
- Do not apply kerosene to children under 2 years of age; alternative treatments are recommended for this group.
Factors influencing the required contact time
- Hair thickness: dense hair may impede penetration, necessitating the full 12‑minute interval.
- Ambient temperature: higher temperatures can accelerate kerosene absorption, but the recommended duration remains unchanged to prevent inconsistent results.
- Infestation severity: heavy infestations with many live nymphs may benefit from a repeat treatment after one week.
In summary, maintaining kerosene on the scalp for roughly twelve minutes provides reliable eradication of lice while limiting adverse skin effects. Adherence to the outlined steps and safety measures is essential for effective and safe use.