BS ISO 21285:2019 pdf free

BS ISO 21285:2019 pdf free.Soil quality – Inhibition of reproduction of the soil mite (Hypoaspis aculeifer) by soil contaminants
A preliminary test to find the range of mixture ratio affecting predatory mites is optional, e.g. 0 %,1 %,5 %, 25 %, 50 %, 75 %, 100 % soil, or of the test substance, e.g. 0 mg/kg, 1 mg/kg, 10 mg/kg,100 mg/kg and 1 000 mg/kg [the concentrations being expressed in milligrams of test substance per kilogram of dried control soil (see 5.2.2) and a control using 10 mites per container]. The preliminary test is conducted without replication. The duration of the range finding test is 14 d (exposure time),followed by an extraction time of two days. After a total 16 d, mortality of the adult mites and the number of juveniles is determined. Based on the results of the range finding test, the ER5o/EC50 is roughly determined by calculating the geometric mean of those two concentrations showing 0 % and 100 % mortality. The concentration/dilution range in the final test should preferably be chosen so that it includes concentrations at which juvenile numbers are affected while survival of the maternal generation is not. This, however, may not be possible for substances that cause lethal and sub-lethal effects at similar concentrations.
When no effects are observed, even at 100 % contaminated soil or at concentrations of 1 000 mg test substance/kg standard soil (dry mass), the definitive test can be designed as a limit test.
The design of the definitive test depends on the test objectives. Typically, the habitat properties of samples of a field-collected soil are characterized by comparison of the biological effects found in the soil to be tested with those found in a reference soil, or if not available or not appropriate due to toxicity or atypical physicochemical characteristics, in a standard soil. Results for the standard soil assist in distinguishing contaminant effects from non-contaminant effects caused by soil physicochemical properties. Regardless of whether a reference soil or standard soil is used for the statistical comparisons,the results from standard soil shall be used to judge the validity and acceptability of the test[27]. The duration of the definitive test is 14 d (exposure time), followed by an extraction time of two days. After a total 16 d, mortality of the adult mites and the number of juveniles is determined.BS ISO 21285 pdf free download.