The acute toxicity of water accomodated fraction (WAF) of crude palm kernel oil (CPKO), crude palm kernel stearin (CPKST) and crude palm kernel olein (CPKOL) to Acartia tonsa (a marine copepod) and Skeletonema constatum ( a chain forming marine algae) was determined at three loading rates: 10,100 and 1000 mg liter^-1. WAF methodlogy was used for the toxicity tests as these palm products are poor water-soluble. Measurement of the carbon (TC) of the test medium before the start of the tests confirmed that there were low levels of stabilized material in the WAFs. The mean concentrations of TC in 1000 mg litre^-1 WAFs prepared from palm kernel oil, palm kernel stearin and palm kernel olein were 4.5, 1.0 and 5.2 mg litre^-1, respectively. All the palm products tested were not toxic to A. tonsa. Palm kernel oil and palm kernel olein were harmless to S. costatum at a loading rate of 10 mg litre^-1. They were slightly toxic at 100 mg litre^-1 and toxic at 1000 mg litre^-1. Palm kernel stearin wea harmless to S. constatum at a loading rate of 100 mg litre^-1 and only slightly toxic at 1000 mg litre^-1.