How long does poison ivy oil last on clothing?

Poison ivy oil, specifically urushiol, can remain active on clothing for varying lengths of time, typically for several weeks to months if not properly cleaned. The oil can adhere to fabrics, and even a small amount can cause allergic reactions. It's essential to wash contaminated clothing thoroughly with hot water and detergent to remove the urushiol. If the clothing is not washed, the oil may remain potent until it eventually degrades.