ISO 23404:2020

Overview

ISO 23404:2020 - Information and documentation - Papers and boards used for conservation - Measurement of impact of volatiles on cellulose in paper - specifies a laboratory test method to assess how volatile compounds emitted from conservation papers and boards affect cellulose in paper-based collections. The method uses accelerated ageing in sealed glass vials and measures changes in cellulose molecular size (viscosity‑average degree of polymerization, DPv) of a purified reference paper to quantify depolymerization caused by volatiles. The standard applies to papers and boards used for conservation and storage of cellulose‑based items (not parchment) and can be extended to museum artefacts; it does not evaluate effects from direct physical contact.

Key topics and technical requirements

• Test principle: expose a pure‑cellulose reference paper to volatiles emitted by the test material at elevated temperature in closed vessels; compare DPv of exposed vs. unexposed reference paper to determine loss of DPv.
• Reference material: cellulose filter paper (cotton linter) with ≥98% alpha cellulose; specified grammage and thickness.
• Apparatus: borosilicate glass vials with airtight screw caps and inert gaskets (materials must be stable at test conditions), optional inner vessels and microtubes, viscometer compliant with ISO 5351, fan‑forced ageing chamber thermostatted at 100 °C.
• Sample handling & preparation: cleaning and oven‑drying of glassware (105 °C), conditioning samples and reference paper at (23 ± 1) °C and (50 ± 2) % RH per ISO 187, determination of dry matter by ISO 638.
• Measurements and calculations: limiting viscosity number in cupri‑ethylenediamine (CED) solution per ISO 5351 to obtain DPv; validation procedures for control and test vials; expression of results as loss of DPv.
• Quality controls: vial sealing checks, avoidance of cross‑contamination, representative sampling (ISO 186).

Applications and who uses it

• Conservation scientists and conservators assessing long‑term chemical risks of storage and conservation materials.
• Collection care managers in museums, archives and libraries specifying or approving papers and boards for storage boxes, folders and mounts.
• Test laboratories and manufacturers of conservation materials who need to demonstrate materials do not emit harmful volatiles.
• Procurement and specification authors aiming to complement ISO 16245 by adding evaluation of volatile emissions.

Related standards

• ISO 16245 (materials for archive and library containers)
• ISO 186 (sampling)
• ISO 187 (conditioning)
• ISO 638 (dry matter content)
• ISO 5351 (viscosity / DP measurement)
• ISO 14487 (standard water for testing)

Keywords: ISO 23404:2020, conservation papers, boards, volatiles, cellulose, degree of polymerization, accelerated ageing, museum conservation, archival storage.