Abstract: This study was focused to assess efficiency and toxicity of an oil dispersant (Adt type 3) under the laboratory conditions. Swirling Flask Test (SFT) and Baffled Flask Test (BFT) were used for effectiveness assessments using Murban crude oil (density 0.837gcm-3) as the reference oil. The locally made baffled flask was used with 100μl of oil, 4μl of dispersant and120ml of filtered seawater at 1:25 dispersant to oil ratio. The SFT was followed using1:10 dispersant to oil ratio and the dispersant efficiency was expressed as a ratio between amount of oil initially added to test flask and amount of oil extracted to dichloromethane (DCM).