How do you make a spray for lice?

How do you make a spray for lice? - briefly

Combine a mild surfactant such as liquid dish soap with distilled water and a few drops of an essential oil that repels lice, then pour the mixture into a spray bottle. Apply to hair and scalp, let act for ten minutes, and rinse thoroughly.

How do you make a spray for lice? - in detail

Creating an effective lice‑removing spray requires a combination of proven insecticidal agents, safe carriers, and stabilizers. The formulation must target the nymph and adult stages of Pediculus humanus capitis while minimizing irritation to the scalp.

The base solution typically consists of distilled water and a mild surfactant to improve spreadability. A recommended proportion is 90 % water to 10 % surfactant, such as sodium lauryl sulfate, measured by volume. The surfactant reduces surface tension, allowing the active ingredient to penetrate the exoskeleton of the insects.

Active components commonly employed include:

• 1 % permethrin (synthetic pyrethroid) – neurotoxic to lice, low toxicity to humans when used as directed.
• 0.5 % dimethicone (silicone oil) – suffocates lice by coating their respiratory spiracles.
• 0.2 % piperonyl butoxide – synergist that enhances the efficacy of permethrin.

To prepare the spray:

1. Warm distilled water to approximately 30 °C; temperature assists dissolution of surfactant.
2. Add the surfactant slowly while stirring; continue until a clear, homogeneous mixture forms.
3. Introduce the active ingredients one at a time, maintaining constant agitation to avoid precipitation.
4. Incorporate a preservative, such as 0.1 % phenoxyethanol, to extend shelf life.
5. Adjust pH to 5.5–6.0 using citric acid or sodium hydroxide; this range is compatible with scalp skin.
6. Transfer the final solution into a clean, amber‑colored spray bottle equipped with a fine‑mist nozzle.

Application guidelines:

• Apply a generous mist to dry hair, ensuring coverage from scalp to tips.
• Allow the spray to remain for 10 minutes before rinsing with lukewarm water.
• Repeat the procedure after 7 days to eliminate newly hatched lice.

Storage recommendations:

• Keep the bottle in a cool, dark place.
• Use within 3 months of preparation; observe any changes in odor or clarity as indicators of degradation.

Safety precautions:

• Avoid contact with eyes; rinse immediately with water if exposure occurs.
• Conduct a patch test on a small scalp area 24 hours before full application to detect possible hypersensitivity.