Corrosion Testing Standards

The test standard summaries are for general guidance only. Though believed to be accurate at the time of writing, this may change over time. So this information should not be used as a substitute for referring to a complete test standard, at an appropriate revision level.

Note: the terms salt spray, salt mist and salt fog are all in wide spread use within corrosion test standards. In this context they can be considered to be equivalent and interchangeable terms.

ISO 7253

Paints & varnishes – determination of resistance to neutral salt spray (fog)

Can be used to test the relative resistance to corrosion of paints and varnishes, when exposed to a salt spray (fog) climate at an elevated temperature.

Test specimens are placed in an enclosed chamber and exposed to a continuous indirect spray of neutral (pH 6.5 to 7.2) salt water solution, which falls-out on to the specimens at a rate of 1.0 to 2.5ml/80cm²/hour, in a chamber temperature of +35C. This climate is maintained under constant steady state conditions. The test duration is variable.

Chamber volumes of less than 400 Litres are not permitted by this test standard.

This test is also referred to as a Neutral Salt Spray or NSS test.

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Note; many ISO test standards have been harmonized with other European standards and these are now prefixed ‘EN’ (Euro Norm) or ‘** EN’ – where ** are the letters representing a European country/language code, for example ‘BS EN’ for a harmonized British standard in English language.