Do not use a product if the person being treated is allergic to any of its ingredients. In Ontario the most common head lice products contain permethrin or pyrethrins. Follow the directions very carefully. Do not use on children under age 2 unless directed by a physician. For older children, caution is recommended, as the potential for toxic effects is greater in the young.
Timing is important.
If the product is rinsed off too soon, lice and eggs may not be killed. If left on too long, you are causing unnecessary chemical exposure. These products should not be used near the eyes, nose or mouth. Hold a towel tightly over the eyes to protect them during treatment. When treating another person, wear plastic or rubber gloves and wash your hands well.