Full Description ADOPTED_FROM:EN ISO 21285:2020 This document specifies a chronic test method for evaluating the habitat function of soils and determining effects of soil contaminants and substances on the reproduction of Hypoaspis aculeifer by ? mainly ? alimentary uptake. This method is applicable to soils and soil materials of unknown quality, e.g. from contaminated sites, amended soils, soils after remediation, industrial, agricultural or other sites under concern and waste materials (e.g. dredged material, municipal sludge from a wastewater treatment plant, composed material, or manure, especially those for possible land disposal). The reproduction (= number of juveniles) is the measured parameter of the test. The test reflects the bioavailability of a mixture of contaminants in natural soils (contaminated site soils) to a species which represents a trophic level which is not covered by other ISO standards. This test is not intended to replace the earthworm (see ISO 11268-2) or Collembola (see ISO 11267) reproduction tests since this species belongs not only to a different trophic group but also a different taxonomic group (= mites; i.e. arachnids) than those used usually. Effects of substances are assessed using a standard soil, preferably a defined artificial soil substrate. For contaminated soils, the effects are determined in the soil to be tested and in a control soil. Depending on the objective of the study, the control and dilution substrate (dilution series of contaminated soil) are either an uncontaminated soil comparable to the soil to be tested (reference soil) or a standard soil (e.g. artificial soil). This document provides information on how to use this method for testing samples (soils or substances) under temperate conditions. This document is not applicable to substances for which the air/soil partition coefficient is greater than one, or to substances with vapour pressure exceeding 300 Pa at 25 °C. NOTE The stability of the test substance cannot be ensured over the test period. No provision is made in the test method for monitoring the persistence of the substance under test.