ISO 11268-1:2012

Overview

ISO 11268-1:2012 - "Soil quality - Effects of pollutants on earthworms - Part 1" - specifies a standardized laboratory method to determine the acute toxicity of soils, soil materials and chemicals to earthworms (Eisenia fetida / Eisenia andrei). The test evaluates the habitat function of soil by measuring earthworm survival after dermal and alimentary exposure to contaminated or amended soils, using either a reference soil or a standard (artificial) soil as control.

Key topics and technical requirements

• Test organisms: Adult Eisenia fetida or Eisenia andrei (≥3 months, with clitellum), selected for homogeneous size and mass.
• Endpoints: Survival, reported as mortality, NOEC (no observed effect concentration) and LC50 (median lethal concentration after test period).
• Test duration: Effects assessed after 7 and 14 days; a preliminary test determines appropriate concentration ranges and a definitive test establishes dose–response (10–90% mortality targeted). A single-concentration limit test is allowed when preliminary mortality is absent.
• Sample handling: Field soils sieved at 4 mm, air-dried if needed, stored per ISO 10381-6; key soil properties (pH, texture, water content, water‑holding capacity, cation exchange capacity, organic carbon) must be measured.
• Mixtures and controls: Test mixtures expressed as percentage of contaminated soil (dry mass); controls must be either comparable uncontaminated soil (reference) or standard soil.
• Exclusions and caveats: Not applicable to volatile substances (Henry’s constant or air/water partition coefficient > 1, or vapour pressure > 0.0133 Pa at 25 °C). The method does not account for chemical degradation during the test.
• Documentation & analysis: Requirements include experimental design, preparation, test conditions, reference substance use, calculation methods, validity criteria and statistical analysis.

Applications and users

ISO 11268-1 is used by:

• Environmental testing laboratories conducting soil ecotoxicity assays
• Regulators and risk assessors evaluating contaminated sites, land‑disposal suitability and remediation outcomes
• Remediation practitioners monitoring biological recovery after treatment
• Pesticide and chemical manufacturers performing acute toxicity screening under temperate and tropical conditions
• Researchers in soil ecology and ecotoxicology

Practical benefits include standardized, comparable acute toxicity data (LC50, NOEC) for decision-making on site management, remediation prioritization and chemical hazard assessment.

Related standards

Key normative references and complementary standards:

• ISO 10381-6 (soil sampling/storage)
• ISO 10390 (pH)
• ISO 10694 (organic carbon)
• ISO 11260 (cation exchange capacity)
• ISO 11277 (particle size distribution)
• ISO 11465 (water content)

Keywords: ISO 11268-1, soil quality, earthworm toxicity test, Eisenia fetida, Eisenia andrei, acute toxicity, LC50, NOEC, contaminated soils, artificial soil, ecotoxicology.