ISO 17402:2008

Overview

ISO 17402:2008 - Soil quality: Requirements and guidance for the selection and application of methods for the assessment of bioavailability of contaminants in soil and soil materials - provides a harmonized framework to select, apply and develop methods that estimate the bioavailable fraction of contaminants. The standard focuses on practical guidance rather than prescribing a single “best” method. It covers metals (including metalloids), organic contaminants (including organometal compounds) and is also applicable to sediments and naturally occurring pedo‑geochemical metal content. Results from methods described under ISO 17402:2008 can be used to refine exposure estimates within risk assessment and site‑characterisation workflows.

Key topics and requirements

• Purpose and scope: Guidance for method selection and application to characterise contaminated soil/soil materials; minimal requirements for method development.
• Method concepts: Distinguishes between chemical (e.g., extraction, leaching) and ecotoxicological (biological exposure/effect) approaches to assess bioavailability (see Clause 6).
• Pathways and receptors: Addresses exposure pathways relevant to humans and ecological receptors - ingestion, dermal contact, inhalation, groundwater leaching, plant and soil‑organism uptake (Clause 7).
• Available methods: Summarises existing chemical and biological methods and highlights promising approaches for further standardization (Clause 8).
• Selection and application requirements: Defines boundary conditions, principles, and minimal requirements for selecting and applying methods and for method development (Clause 9).
• Use in risk assessment: Emphasises translating bioavailability estimates into exposure inputs for risk‑based decision making and site‑specific remediation endpoints.
• Supplementary guidance: Includes annexes on bioavailability vs biodegradability and references to standards for sediment toxicity testing.

Practical applications and users

ISO 17402:2008 is intended for professionals involved in contaminated land assessment and management:

• Environmental consultants and site assessors conducting site characterisation and risk assessments.
• Environmental and analytical laboratories developing or validating bioavailability testing methods.
• Regulators and policy makers using bioavailability‑based approaches to set site‑specific cleanup criteria and optimize remediation decisions.
• Researchers advancing correlations between chemical extractions, bioaccessibility and biological effects.
• Remediation contractors and planners applying results to prioritize actions and reduce unnecessary remediation costs.

Practical benefits include more realistic exposure estimates than total‑concentration approaches, improved protection‑goal alignment, and support for cost‑effective, site‑specific remediation strategies.

Related standards

ISO 17402:2008 references and complements other International Standards for chemical and ecotoxicological testing and sediment toxicity methods. It provides guidance for further standardization rather than replacing existing test standards. For authoritative method details, users should consult the ISO soil‑quality standards and standardized ecotoxicity protocols cited within ISO 17402:2008.