ISO 21285:2019

Overview

ISO 21285:2019 - Soil quality: Inhibition of reproduction of the soil mite (Hypoaspis aculeifer) by soil contaminants specifies a chronic ecotoxicological test method for assessing the habitat function of soils. The standard measures reproduction (number of juveniles) of the predatory soil mite Hypoaspis aculeifer as an endpoint to determine the bioavailability and toxic effects of contaminants in soils, amended materials and wastes. It is designed for temperate conditions and applies to contaminated site soils, remediated soils, industrial/agricultural sites, and wastes considered for land disposal. The method complements other soil organism tests (earthworms, Collembola) by covering a different trophic and taxonomic group (mites/arachnids).

Key topics and requirements

• Test endpoint: inhibition of reproduction (juvenile count) of H. aculeifer as a measure of chronic effects and bioavailability of contaminant mixtures.
• Scope of materials: natural soils, artificial (standard) soils, soil amendments and wastes (e.g., dredged material, sewage sludge, compost, manure).
• Test design elements: experimental design, range-finding, definitive and limit tests, preparation of test mixtures, addition of biological material, feeding, survival and juvenile counting, calculation and expression of results, validity criteria and statistical analysis.
• Control and reference: use of either a comparable uncontaminated reference soil or a defined artificial soil for controls and dilution series.
• Exclusions/limitations: not applicable to substances with air/soil partition coefficient > 1 or vapour pressure > 300 Pa at 25 °C. The standard does not include monitoring of test-substance persistence during the exposure.
• Supporting guidance: annexes cover rearing techniques, water-holding capacity determination, pH adjustment of artificial soil, extraction and counting methods, and basic biological information on H. aculeifer.
• Referenced standards: includes related soil property and sampling standards (e.g., ISO 10390 pH, ISO 11465 water content, ISO 18400‑206 sampling).

Applications

• Site risk assessment and ecological evaluation of contaminated lands and brownfields.
• Pre‑ and post‑remediation testing to verify remediation effectiveness on soil habitat function.
• Ecotoxicological characterization of wastes and materials proposed for land disposal.
• Laboratory testing to support regulatory assessment of soil contamination and non‑target organism impacts.
• Research into mixture bioavailability and trophic-level effects in soil ecosystems.

Who should use this standard

• Environmental laboratories and ecotoxicology testing facilities
• Soil scientists and environmental consultants assessing contaminated sites
• Remediation contractors and waste managers evaluating land disposal suitability
• Regulatory agencies and risk assessors developing soil quality and protection measures
• Researchers studying soil food‑webs, bioavailability and effects of contaminants on soil arthropods

Related standards

• ISO 11268‑2 (earthworm reproduction test)
• ISO 11267 (Collembola reproduction test)
• ISO 15799 and ISO 17616 (guidance on ecotoxicological test selection)
• OECD protocols for predatory mites (reference for comparable methods)

Keywords: ISO 21285:2019, soil quality, Hypoaspis aculeifer, soil mite reproduction test, ecotoxicology, contaminated soils, bioavailability, standard soil, chronic test method.