The toxicities of palm-based alpha-sulphonated methyl esters (SME) produced in MPOB’s SME pilot plant were consistent throughout the production period, i.e.around 1.00-1.41 mg litre^-1 . Its toxicity was comparable to two palm-based commercial SMEs whether tested in temperate or tropical environment. The surfactants were found to be less toxic when tested under tropical conditions. The toxicity is related to the carbon chain length of methyl esters used to produce SME. Higher carbon chain length will cause an increase in the toxicity of anionic surfactant as seen in palm-based SME (C_16/18) and commercial SME 1 (C_16/18). Commercial SME 2 (C_14/16) was slightly less toxic due to the lower carbon chain length. Their toxicities, however, were still within the same toxicity range, i.e. moderately toxic. Palm-based SME is not expected to cause environmental concern due to only 10% – 30% of it is used in detergent products, its biodegradability was more than 80% in only eight days and the dilution in aquatic environment will cause the local predicted environmental concentration to be very low. The use of palm-based SME will help to stimulate Malaysia’s agricultural economies and lessen our dependence on imported petroleum-based surfactants.