ISO 10312-2019 PDF

Full title and description

ISO 10312:2019 — Ambient air — Determination of asbestos fibres — Direct transfer transmission electron microscopy method. This international standard specifies a reference method using transmission electron microscopy (TEM) with direct-transfer specimen preparation for identifying and quantifying airborne asbestos fibres and related structures in ambient atmospheres (including indoor atmospheres).

Abstract

ISO 10312:2019 defines a TEM-based reference procedure to determine the presence, types and dimensional characteristics (length, width, aspect ratio) of asbestos fibres and fibrous structures in a wide range of ambient-air situations. The method provides identification and measurement rules and records the degree to which identification criteria were met for each counted structure; it does not always discriminate asbestos from non‑asbestos amphibole cleavage fragments. The document is the second edition (2019) and updates earlier provisions for specimen handling, reporting and permitted analytical practices.

General information

• Status: Published (confirmed).
• Publication date: October 2019 (Edition 2, 2019-10).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 13.040.20 — Ambient atmospheres; ISO/TC 146/SC 3.
• Edition / version: 2 (2019).
• Number of pages: 72 pages (ISO official record).

Key bibliographic and status details are recorded on the ISO catalogue entry for ISO 10312:2019.

Scope

Specifies a reference TEM method (direct-transfer preparation) for determination of airborne asbestos fibres and fibrous structures in ambient atmospheres, including indoor air. The standard covers specimen preparation for several filter types, TEM operating and imaging conditions, morphological classification and mineralogical identification procedures, counting and sizing of structures, recording of identification confidence levels, and reporting options (including options to report concentrations of fibres/bundles longer than 5 µm or PCM-equivalent fibres under defined conditions). The method is intended for environmental surveys and detailed atmospheric evaluations rather than routine occupational PCM monitoring.

Key topics and requirements

• Direct-transfer TEM specimen preparation (filter clearing / collapse and transfer to EM grids) with specified reagents and procedures to preserve collected particles for TEM imaging and analysis.
• Requirements for sampling (filter type, pump stability and face velocity ranges) and acceptable particulate loading on TEM specimens; guidance for overloaded samples and use of indirect-transfer methods when appropriate.
• TEM imaging, measurement and classification rules: measurement of lengths, widths and aspect ratios; coded recording of structure morphology and identification confidence to allow later re-evaluation.
• Mineralogical identification guidance (where needed) using TEM features and ancillary analytical techniques to discriminate asbestos types, with notes about limitations in distinguishing asbestos from some non-asbestiform amphibole fragments.
• Reporting and reporting options (including permitted reporting of fibres/bundles >5 µm or PCM-equivalent fibre concentrations, and revised reporting/uncertainty conventions introduced in the 2019 edition).
• Quality control, blanks, and laboratory practices to ensure reliable counts (including use of field blanks and specimen acceptability checks).

Typical use and users

Used by environmental and analytical laboratories, occupational and environmental hygiene professionals, regulatory agencies, consultants and researchers conducting detailed asbestos surveys, environmental exposure assessments, forensic investigations, and method development. Laboratories performing ISO 10312 analyses commonly participate in quality assurance programs and may be accredited to relevant laboratory competency standards.

Related standards

Closely related and complementary documents include ISO 13794:2019 (Indirect-transfer TEM method for ambient air asbestos analysis) and the withdrawn earlier edition ISO 10312:1995 (replaced by the 2019 edition). National and sector methods (for example NIOSH TEM methods such as Method 7402 and EPA/NIOSH guidance) are also used alongside ISO 10312 for occupational and regulatory applications. Laboratories often follow ISO/IEC 17025 for analytical competence when offering asbestos TEM testing.

Keywords

asbestos; ambient air; transmission electron microscopy; TEM; direct-transfer; specimen preparation; fibre counting; fibre sizing; ISO 10312:2019; ambient atmospheres; ISO/TC 146/SC 3.

FAQ

Q: What is this standard?

A: ISO 10312:2019 is an international reference method that specifies a direct-transfer TEM procedure for identifying and quantifying asbestos fibres and related structures in ambient air.

Q: What does it cover?

A: It covers sampling and specimen preparation (direct-transfer), TEM imaging and measurement, structure classification and identification, counting and reporting rules, and quality-control practices for ambient‑air asbestos analyses. The standard also notes limitations in distinguishing certain non-asbestiform amphibole fragments from asbestos.

Q: Who typically uses it?

A: Environmental and occupational hygiene laboratories, exposure assessors, regulatory and public‑health bodies, consultants and researchers who need a TEM-based, high-resolution method for asbestos identification and quantitative characterization in ambient atmospheres.

Q: Is it current or superseded?

A: ISO 10312:2019 is the current (second) edition, published October 2019; ISO records show the publication was reviewed and confirmed in 2025 and remains current. It replaces the 1995 edition.

Q: Is it part of a series?

A: Yes — it is part of the family of ISO standards for ambient-air asbestos TEM methods (for example ISO 13794:2019 for indirect-transfer TEM) and is used alongside regional/national TEM and PCM methods (e.g., NIOSH methods) for comprehensive asbestos assessment strategies.

Q: What are the key keywords?

A: Asbestos, ambient air, TEM, direct-transfer, fibre counting, fibre sizing, identification, ISO 10312, ambient atmospheres.