ISO 21316:2026

• Abstract:

  This document specifies the minimum requirements and test methods for Isatis indigotica root derived from the plant Isatis indigotica Fort. It is applicable to Isatis indigotica roots that are sold as Chinese material medica (whole medicinal materials) and decoction pieces derived from this plant.

• Status: Published
• Publication Date: 09-Jul-2026
• ICS: 11.120.10 - Medicaments
• Technical Committee: ISO/TC 249 - Traditional Chinese medicine
• Drafting Committee: ISO/TC 249/WG 1 - Quality and safety of raw materials and traditional processing
• Current Stage: 6060 - International Standard published
• Start Date: 10-Jul-2026
• Due Date: 05-Aug-2026
• Completion Date: 10-Jul-2026

• Revises: ISO 21316:2019 - Traditional Chinese medicine — Isatis indigotica root
• Effective Date: 08-Feb-2025

Overview

ISO 21316:2026 – Traditional Chinese Medicine – Isatis indigotica Root is an international standard that defines the minimum requirements and test methods for Isatis indigotica root, a widely used herbal ingredient in Traditional Chinese Medicine (TCM). Developed by ISO/TC 249/SC 1, this standard applies to both whole roots and decoction pieces derived from the Isatis indigotica Fort. plant.

Isatis indigotica root (commonly known as “Banlangen” in Chinese) has a long history in East Asian medicine, recognized for its role in removing heat and toxins from the body and supporting the prevention and treatment of colds and infectious diseases. Given its growing global market and varying regional quality standards, ISO 21316 ensures consistency, quality, and safety for international commerce and clinical practice.

Key Topics

The standard covers the following primary areas:

• Minimum quality requirements: Defines criteria for appearance, dimensions, texture, odour, and absence of foreign matter.
• Morphological and physical features: Establishes standards for root shape, fracture, colour, and structure.
• Chemical composition and purity: Specifies methods for determining moisture, total ash, acid-insoluble ash, ethanol-soluble extractives, and (R,S)-goitrin content.
• Identification and authentication: Describes thin-layer chromatography (TLC) and macroscopic/microscopic methods to verify authenticity and quality.
• Heavy metals and pesticide residues: Provides requirements and methodologies for measuring contaminants such as arsenic, mercury, lead, cadmium, and specific pesticide residues.
• Sampling procedures: Outlines standardized sampling and handling methods for batches and containers to ensure representative and reliable testing.
• Packaging, storage, and labelling: Details appropriate packaging materials, storage environments, and information to be included on product labels as per ISO guidelines.

Applications

ISO 21316 offers significant practical value across several domains in the supply and use of Isatis indigotica root:

• Herbal product manufacturers: Ensures the consistent quality of raw materials and decoction pieces, facilitating access to international markets and compliance with import/export regulations.
• Quality assurance laboratories: Provides standardized, repeatable test methods for verifying product safety, purity, and authenticity.
• Regulators and health authorities: Assists in establishing baseline requirements for TCM products, supporting public health, safety, and effective regulation.
• Importers/exporters and wholesalers: Simplifies due diligence by offering clear benchmarks for product acceptance and reducing trade disputes related to quality and compliance.
• Healthcare practitioners: Increases confidence in the safety and effectiveness of Isatis indigotica root used in clinical practice.

Related Standards

ISO 21316 references and aligns with several other internationally recognized standards relevant to traditional herbal products, including:

• ISO 18664: Determination of heavy metals in herbal medicines
• ISO/TS 21310: Microscopic examination of medicinal herbs
• ISO 21371: Labelling requirements for oral or topical TCM products
• ISO 22217: Storage requirements for raw materials and decoction pieces
• ISO 22258: Determination of pesticide residues by gas chromatography
• ISO 23723: General requirements for herbal raw material and materia medica

By harmonizing its protocols with these standards, ISO 21316 supports comprehensive quality management for Isatis indigotica root at every stage, from field to pharmacy.

Keywords: ISO 21316, Isatis indigotica root, Traditional Chinese Medicine, herb quality standard, herbal extractives, Banlangen, herbal material testing, (R,S)-goitrin, TCM international standard.

International
Standard
ISO 21316
Second edition
Traditional Chinese medicine —
2026-07
Isatis indigotica root
Médecine traditionnelle chinoise — Racine d'Isatis indigotica
Reference number
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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or ISO’s member body in the country of the requester.
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Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Descriptions . 2
5 Requirements and recommendations . 4
5.1 General .4
5.2 Morphological features .4
5.2.1 Appearance .4
5.2.2 Colour .4
5.2.3 Dimension .4
5.2.4 Stem residue .4
5.2.5 Texture .4
5.2.6 Fracture .4
5.2.7 Odour .4
5.3 Moisture .4
5.4 Total ash .4
5.5 Acid-insoluble ash .4
5.6 Ethanol-soluble extractives .5
5.7 Identification of marker compound .5
5.8 Marker compound(s) .5
5.9 Heavy metals .5
5.10 Pesticide residues .5
6 Sampling . 5
7 Test methods . 6
7.1 Macroscopic identification .6
7.2 Microscopic identification .6
7.3 Determination of moisture content .6
7.4 Determination of total ash content .6
7.5 Determination of acid-insoluble ash content .6
7.6 Determination of ethanol-extractives content .6
7.7 Thin-layer chromatogram (TLC) identification .6
7.8 Determination of marker compound(s).6
7.9 Determination of heavy metals contents .6
7.10 Determination of pesticide residues contents.6
8 Test report . 6
9 Packaging, storage and transportation . 7
10 Marking and labelling . 7
Annex A (informative) Determination of ethanol-soluble extractives . 8
Annex B (informative) Thin-layer chromatogram (TLC) identification . 9
Annex C (informative) Determination of (R,S)-goitrin content .11
Annex D (informative) National and regional limits of moisture, total ash, acid-insoluble ash,
(R,S)-goitrin and ethanol-soluble extractive contents in Isatis indigotica root .13
Bibliography . 14

iii
Foreword
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in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
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https://www.iso.org/foreword-supplementary-information.html.
This document was prepared by Technical Committee ISO/TC 249, Traditional medicine, Subcommittee SC1,
Traditional Chinese medicine.
This second edition cancels and replaces the first edition (ISO 21316:2019) which has been technically
revised.
The main changes are as follows:
— 5.3 to 5.6: change of mandatory requirements to recommendations;
— information updates in the document and Annex D.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
Isatis indigotica root (Banlangen in Chinese pinyin; 板蓝根 in Chinese), dried root of Isatis indigotica Fort.
(Fam. Brassicaceae), is one of the most commonly used herbs in traditional Chinese medicine (TCM). It has
a long history of use in East Asian countries to remove heat and toxins, cool the blood and clear the throat.
Clinically, Isatis indigotica root is recognized as an important traditional Chinese herb for the prevention
and treatment of colds and malignant infectious diseases, especially SARS and H1N1. At present, Isatis
indigotica root and its processed products occupy a huge share of the international market. However, many
problems, such as different quality requirements among different countries and regions, adulteration with
Baphicacanthis root derived from the dried root and rhizome of Baphicacanthus cusia (Nees) Bremek (Fam.
Acanthaceae), and different packaging, transportation and storage conditions, can affect the quality of Isatis
indigotica root.
Therefore, the establishment of an international standard is necessary to establish the quality requirements
of Isatis indigotica root to support its clinical effectiveness and safety. This document consists of a
morphology observation of macroscopic characteristics, phytochemical indexes, and standardized physical
and chemical tests (moisture, total ash and acid-insoluble ash). Glucosinolates with multi-bioactivities are
specific compositions of the plant in the Brassicaceae family. Among them, (R,S)-goitrin with high specificity
reflects bioactivities relevant to the effects of Isatis indigotica root. Using (R,S)-goitrin as the marker, TLC
identification and HPLC assay methods are established in this document.
As national implementation may differ, examples of national and regional values are given in Annex D.

v
International Standard ISO 21316:2026(en)
Traditional Chinese medicine — Isatis indigotica root
1 Scope
This document specifies the minimum requirements and test methods for Isatis indigotica root derived from
the plant Isatis indigotica Fort.
It is applicable to Isatis indigotica roots that are sold as Chinese material medica (whole medicinal materials)
and decoction pieces derived from this plant.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 18664, Traditional Chinese Medicine — Determination of heavy metals in herbal medicines used in
Traditional Chinese Medicine
ISO/TS 21310, Traditional Chinese medicine — Microscopic examination of medicinal herbs
ISO 21371, Traditional Chinese medicine — Labelling requirements of products intended for oral
...