Overview
ISO 3298:1994 - “Photography - Processing chemicals - Specifications for glacial acetic acid” defines purity criteria and test methods for glacial acetic acid intended for photographic processing. The standard sets minimum chemical quality limits, prescribes analytical methods (or references them), and gives handling and safety guidance relevant to laboratory use. Tests are performed on samples “as received” to reflect material actually used in processing solutions.
Key topics and technical requirements
- Purity (titre): Minimum content of acetic acid is 99.5% (m/m). Titration methods are used where applicable as both purity and identity checks.
- Non‑volatile matter: Maximum 0.005% (m/m). Example procedure: evaporate a measured sample and dry residue at 105 ± 2 °C for 1 hour; residue mass must not exceed the specified limit.
- Heavy metals: Maximum 0.002% (m/m) (e.g., lead). Determination is by methods referenced to ISO 10349‑5.
- Iron (Fe): Maximum 0.001% (m/m), with test procedures referenced to ISO 10349‑5.
- Appearance: Solution must be transparent and colourless on comparison with water after specified dilution.
- Physical characteristic: The standard includes a melting point check during one of the procedures (acceptance note indicates a melting point not lower than about 15.7 °C).
- Safety & handling: Notes that glacial acetic acid causes severe skin burns and is toxic by ingestion; laboratory PPE and safe practices are required (see ISO 10349‑1 for hazard codes and handling guidance).
- Test method precedence: Where advanced instrumental methods are used as substitutes, correlation with the specified methods is the user’s responsibility; if results conflict, the standard’s methods prevail.
Applications and users
ISO 3298 is intended for:
- Photographic chemical manufacturers and suppliers certifying glacial acetic acid for photographic use
- Quality control and analytical laboratories testing incoming chemicals
- Photographic processors, film and paper labs, and conservation studios that require assurance of chemical purity to avoid image defects
- Procurement and compliance teams specifying chemical quality for photographic processing workflows
Practical value: using ISO 3298 helps prevent unwanted photographic effects (staining, fogging, precipitates) caused by impurities, and ensures consistent, reproducible processing performance.
Related standards
- ISO 10349‑1: General methods and safety symbols for photographic quality chemicals
- ISO 10349‑5: Methods for determination of heavy metals and iron referenced by ISO 3298
Keywords: ISO 3298, glacial acetic acid, photography processing chemicals, purity specifications, non‑volatile matter, heavy metals, iron content, ISO 10349.