Salt spray test

A number of standardised tests have been developed to provide a quick indication of corrosion resistance and to enable different materials or coatings to be compared in terms of their corrosion resistance. The most commonly used test is the salt spray test.

How does the salt spray test work?

The test specimens are placed in a sealed chamber where a fine salt spray is dispensed at a temperature of approximately 35°C. This mist consists of a salt solution containing 5% sodium chloride (similar to seawater). The material is exposed to the mist for a specified period. After the test, the damage is assessed: is there any rust formation, blistering of the paint, discolouration or any other sign of corrosion?

What does the test reveal?

The salt spray test provides information on:

  • The corrosion resistance of a material or coating in a marine environment
  • The quality and durability of protective coatings (paint, zinc, powder coating, etc.)
  • Comparisons between different products, treatments and suppliers

Related standards

  • EN ISO 9227 – Corrosion tests in artificial atmospheres – Salt spray tests
  • ASTM B 117 - Standard practice for operating salt spray (fog) apparatus