ISO 9706:2025

Overview

ISO 9706:2025 - "Information and documentation - Paper for documents - Requirements for permanence" defines requirements for permanent paper intended for long‑term storage of unprinted documents in protected environments (libraries, archives, museums, public records). The second edition updates the 1994 standard and focuses on measurable paper properties that predict chemical and physical stability over long periods. It is applicable to unprinted papers (not boards) and is not intended for materials stored under hostile conditions (high humidity, heat, radiation, pollutants, or water exposure).

Key topics and technical requirements

ISO 9706 specifies a set of quantitative tests and limits to screen papers for permanence. Main technical topics include:

• Mechanical strength

  • Minimum strength assessed by tearing resistance (Elmendorf method, ISO 1974) to ensure handling and readability over time.

• Alkali reserve

  • Presence of alkaline buffering compounds (e.g., calcium carbonate) measured per ISO 10716 to neutralize acids formed during ageing.

• Resistance to oxidation (low lignin content)

  • Requirement expressed via Kappa number determination (ISO 302); the 2025 edition retains limits to control oxidizable matter that causes yellowing and loss of strength (Kappa number threshold referenced in the standard).

• pH of aqueous extract

  • Cold‑extraction pH measurement (ISO 6588‑1) to ensure the paper is not acid‑producing.

• Sampling, conditioning and reporting

  • Sampling and conditioning procedures referenced (ISO 186, ISO 187), plus requirements for test reports and labelling (conformity statement and symbol are included).

Normative references used for testing include ISO 536 (grammage), ISO 1974, ISO 302, ISO 10716, ISO 6588‑1, among others.

Applications and who uses it

ISO 9706 is used to:

• Specify and procure permanent paper for books, legal records, certificates, official files, and archival materials.
• Provide acceptance criteria for publishers, printing firms, government agencies, and cultural institutions that require documents to be preserved indefinitely.
• Guide paper manufacturers and converters in producing papers suitable for archival storage.
• Support testing laboratories and quality managers in conformity assessment and labeling of paper products.

The standard is a practical screening tool for ensuring documents remain readable and usable for long durations when stored under controlled conditions.

Related standards

• ISO 11108 - Archival paper permanence and durability (permanence + high durability for frequent use).
• ISO 20494 - Paper stability for general graphic applications (service life approach; accepts optical changes).
  See Annex D of ISO 9706:2025 for a detailed comparison.

Keywords: ISO 9706, permanent paper, paper permanence, archival paper, alkali reserve, Kappa number, document preservation, paper testing.