no observed effect concentration | NOEC
SAINMHÍNIÚ the highest concentration tested in an experiment that does not show any effect on the organism and is expressed as concentration (mg/l) or (mg/m3) TAGAIRT EuroChlor. Abbreviations used in (Eco)toxicology http://www.eurochlor.org/upload/documents/document61.pdf [14.6.2010]
NÓTA In a given study, the actual safe or no effect concentration lies between the NOEC and the lowest-observed effect concentration (LOEC). For algal toxicity tests, the NOEC value will always be lower than the median effective concentration (EC50) value but the LOEC may be either higher orlower than the EC50 value (Adams et al., 1985). The determination of NOEC is highly dependent on the test design, e.g., the selection of test concentrations, the number and spacing of tested doses, the endpoints measured, and the number of replicates (Koolijman et al., 1996; Chapman et al., 1998). In addition, quantification of the NOEC depends critically on the variability of an experiment: less precise experiments lead to high values for NOEC, which could result in wrong decision making (Hoekstra and Van Ewijk, 1993).<BR>Not to be confused with NOEL which is expressed as dose.