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A method to derive environmental quality standards for soil or sediment from aquatic toxicity data and partitioning coefficients is the socalled equilibrium partitioning method (EqP-method). According to van Beelen et al. transformation of aquatic no effect concentrations to soil concentrations can be expressed as Log NOECsoil = log NOECwater - 3 + log Kp (van Beelen P, Verbruggen EM, Peijnenburg WJ."The evaluation of the equilibrium partitioning method using sensitivity distributions of species in water and soil." Chemosphere. 2003 Aug;52,7:1153-62.). The Kp for organic compounds is normalized for the fraction of organic carbon in soil (foc) in relation to the Koc: Kp = foc x Koc. The aquatic NOEC is expressed in ug/L while the resulting NOECsoil is expressed in mg/kg. For standard soil the foc is 5.8%. Logaritmic transformation gives the following equation for standard soil: Kp standard soil = log Koc - 1.237. Based on the key values for Koc the following NOECs for standard soil can be derived:

LogKoc

LogKp

NOECsoil

Unit

5.7

4.463

20328

mg/kg

6.8

5.563

255916

mg/kg

This shows that the worst case NOEC is higher than 20,000 mg/kg, a concentration far exceeding any possible environmental concentration. This means that there is no risk of environmental concentrations reaching levels toxic to soil dwelling organisms. Therefore, further testing for terrestrial toxicity is waived.