Acute and chronic ecotoxicity tests with lindane were carried out using the soil invertebrates Eisenia fetida, Enchytraeus albidus, and Folsomia candida. To assess the influence of soil type on the bioavailability, these tests were carried out in a standard artificial OECD soil and in sandy and loamy field soil. For each species, differences in lindane toxicity were observed for the three soil types. These differences were, however, not related to the organic matter content. The relative differences in lindane toxicity between the soils was species-specific. These results therefore indicate that the pore-water hypothesis, i.e., the pore-water contaminant fraction being the toxicological bioavailable fraction, is not always applicable for organic substances. NOEC, NEC, as well as EC10 data were subsequently used to calculate hazardous concentrations for 5% of the species; this methodology, aimed at setting environmental quality criteria, is discussed.