Sink represents the interface where the insect and acarid repellent, DEET, enters the aquatic surface. As a widely used commercial product, DEET comes the water through everyday human activities such as showering or bathing, and laundering of clothes has been applied with DEET. Water is the most common environmental medium in which DEET has been detected. DEET has been detected in surface water, groundwater, and drinking water. DEET is expected to be moderately mobile and has the potential to leach into groundwater.