ISO 4543:1981

Overview - ISO 4543:1981 in brief

ISO 4543:1981 provides general rules for conducting corrosion tests applicable to storage conditions for metallic and other non‑organic protective coatings. It gives guidance on exposing coated specimens and production articles in heated or unheated storage rooms across a range of microclimates, with or without climatic control. The standard covers test planning, specimen preparation and marking, handling, exposure methods (including wrapped or packaged items), monitoring of environmental factors, periodic assessments, and reporting of results.

Key topics and technical requirements

• Scope: Tests apply to protective metallic, conversion and non‑organic coatings, with or without additive or temporary protection, and to specimens tested singly or in bulk.
• Specimen size & quantity: Test specimens should have a surface area of at least 50 cm² (5 cm × 10 cm); smaller articles can be combined. Use at least three specimens per evaluation when possible.
• Preparation & handling: Clean specimens with methods suitable to the surface but avoid abrasives and solvents that attack the coating. Handle specimens with clean cotton‑gloved hands.
• Marking: Durable, legible markings that do not interfere with visual assessment; methods include positional coding, stamping, numbered plates, or paint on non‑test areas.
• Exposure conditions: Place specimens where they represent actual storage conditions (on racks, shelves or frames made of corrosion‑resistant materials; avoid local heat sources or vents). Store unexposed specimens in dry, controlled atmospheres (RH ≤ 50% or sealed with desiccant). Minimum mounting height and spacing requirements apply (e.g., >0.5 m from roof).
• Environmental monitoring: Record temperature and humidity (hygrothermograph), and where relevant measure SO2, chloride content and dust/deposit rates. Annex provides recommended measurement frequencies and units.
• Test duration & evaluation intervals: Continue exposure until first signs of corrosion; typical periodic assessment intervals include 1 week, 2 weeks, 1–3–6–12–24–36–48–60 months. Evaluate visually and quantitatively where applicable.
• Reporting: Test report must list scope, specimen/substrate/coating details, preparation/application methods, packaging, exposure location/dates, monitoring data, photographic records and a concluded evaluation.

Applications and users

ISO 4543:1981 is practical for:

• Coating manufacturers validating storage durability of protective coatings
• Materials engineers specifying storage and packaging for coated products
• Test laboratories and quality control departments performing corrosion tests
• Warehouse and logistics managers assessing packaging and microclimate effects on coated goods
• Product designers choosing coating type/thickness and temporary protection for storage

Related standards

ISO 4543 references alignment with other international standards for metallic coatings evaluation and measurement methods. Users should consult applicable standards for specific test methods, metallic coating examination criteria and industry‑specific requirements.