Wash with Tecnu Original to remove poison ivy, oak and sumac oils that cause the rash and spreading. Simply apply Tecnu to dry skin, rub vigorously for two minutes, and rinse with water or wipe off with a cloth. Rinsing with water is best. When used within 8 hours after exposure to poison oak, ivy or sumac, Tecnu can remove urushiol oil before the rash begins. Once the rash has started, washing with Tecnu helps remove any toxic oil on the skin; allowing the natural healing process to begin without the possible spreading of poison ivy or oak (re-contamination). If hypersensitive to poison ivy or oak it is best to apply Tecnu all over the body to remove the rash-causing oil (urushiol) that causes spreading. Poison ivy and oak oil can also spread from contaminated clothing, shoes, gloves, tools and pets. Urushiol does not evaporate and can remain on items for years at a time. Use Tecnu Original to wash off the oil and avoid a poison ivy or oak rash from secondary contact. Tecnu is sometimes misspelled as Technu.