ISO 10390-2021 PDF

Full title and description

ISO 10390:2021 — Soil, treated biowaste and sludge — Determination of pH. This International Standard specifies an instrumental method for routine determination of pH (range pH 2 to pH 12) using a glass electrode in a 1:5 (volume/volume) suspension of sample in either water, 1 mol·L⁻¹ potassium chloride (KCl) or 0,01 mol·L⁻¹ calcium chloride (CaCl2).

Abstract

Provides a standardized procedure for preparing test suspensions of air-dried or appropriately pretreated soil, treated biowaste and sludge, for calibrating and using a pH meter with a glass electrode, and for reporting pH measured in H2O, KCl and CaCl2. The method is intended for routine laboratory use and for comparable pH reporting between laboratories.

General information

• Status: Published / Current
• Publication date: 6 April 2021
• Publisher: International Organization for Standardization (ISO)
• ICS / categories: 13.080.10 — Chemical characteristics of soils
• Edition / version: Edition 3 (2021)
• Number of pages: 8

Metadata and edition information as published by ISO and by national/technical catalogues for the 2021 edition.

Scope

Applies to the routine instrumental determination of pH for all types of air-dried soil and treated biowaste samples and (with appropriate provisions) sludges and field-moist samples. The method uses a 1:5 suspension (sample:solution) and covers pH determination in water, in 1 mol·L⁻¹ KCl and in 0,01 mol·L⁻¹ CaCl2. Notes reference relevant sample pretreatment standards (for example ISO 11464 and applicable EN standards).

Key topics and requirements

• Instrumental method using a glass electrode and pH meter; regular calibration with appropriate buffers.
• Preparation of a 1:5 (v/v) suspension of sample in water, 1 mol·L⁻¹ KCl or 0,01 mol·L⁻¹ CaCl2.
• Measurement range pH 2 to pH 12 and procedures to ensure electrode performance and temperature control during measurement.
• Sample preparation recommendations: air-drying (or drying ≤ 40 °C), sieving (typically 2 mm) or specific provisions for untreated treated biowaste and sludges; typical test portions and volumes are specified (routine soils: small test portions, treated biowaste may require larger test portions, e.g., tens of millilitres into a larger liquid volume).
• Mixing and equilibration guidance (example practice: shake/mix for ~60 min then allow to stand for equilibration prior to measurement) to promote repeatability.
• Reporting pH result as pH in H2O, pH in KCl and/or pH in CaCl2 and noting the measurement medium and any sample pretreatment used.

These key requirements and practical details align with the EN/ISO harmonized text and typical laboratory practice for soil and biowaste pH measurement.

Typical use and users

Used by environmental, agronomy and soil laboratories, waste and biowaste treatment facilities, consultants and regulators for soil quality assessment, biosolids/sludge monitoring, compost/treated biowaste characterization, agricultural advisory services and research. Laboratories adopt this standard for routine pH determinations to ensure comparability of results between organizations and jurisdictions.

Related standards

Commonly referenced standards include ISO 11464 (preparation of samples for physico‑chemical analyses), relevant EN versions (EN ISO 10390 series/adoptions), and other ISO soil sampling and analysis documents (for example standards in the ISO 10381 series). The 2021 edition replaces earlier editions ISO 10390:2005 and ISO 10390:1994.

Keywords

pH; soil quality; treated biowaste; sludge; glass electrode; pH meter; KCl; CaCl2; suspension ratio; sample preparation; ISO 10390; soil analysis.

FAQ

Q: What is this standard?

A: ISO 10390:2021 is an International Standard that specifies an instrumental method for routine determination of pH in soils, treated biowaste and sludges using a glass electrode in a 1:5 suspension.

Q: What does it cover?

A: It covers sample suspension preparation (1:5 v/v), the choice of measurement medium (water, 1 mol·L⁻¹ KCl or 0,01 mol·L⁻¹ CaCl2), pH-meter and electrode use and calibration, equilibration/mixing practices and reporting conventions for pH within the range pH 2–12.

Q: Who typically uses it?

A: Accredited testing and research laboratories, environmental consultants, agricultural laboratories, waste/compost/sludge monitoring facilities, regulators and anyone needing standardized, comparable pH measurements of soils and treated biowaste.

Q: Is it current or superseded?

A: ISO 10390:2021 is the current edition (published 6 April 2021) and supersedes ISO 10390:2005 and ISO 10390:1994.

Q: Is it part of a series?

A: It is part of ISO technical work on soil quality and chemical characteristics of soils (ISO/TC 190) and is commonly used alongside related standards such as ISO 11464 (sample preparation) and standards in the ISO 10381 series (sampling and related analyses).

Q: What are the key keywords?

A: pH, soil quality, treated biowaste, sludge, glass electrode, KCl, CaCl2, suspension ratio, sample preparation, ISO 10390.