ASTM B117 Salt Spray Test

Standard: ASTM B117 Standard Practice for Operating Salt Spray (Fog) Apparatus

Scope: ASTM B117 covers the apparatus, procedure, and guidelines to create and sustain the salt spray (fog) test environment. It does not prescribe the interpretation of the results, the exposure periods to be used for the specific products, or the type of test specimen.

Products: Any product or material can be exposed per ASTM B117. The automotive industry relies heavily on this standard for evaluating various vehicle components. For building products, some examples of test specimens include fasteners (nails and screws), cold-formed steel framing (studs), and other metallic products with protective coatings. In some instances, even plastic or composite materials are tested.

Procedure: All test specimens are cleaned and then exposed to an atomized saltwater solution inside the enclosed chamber. The chamber maintains a temperature of 95°F with humidity approaching 100%. Throughout the exposure period, the salt spray is monitored for dispersion throughout the chamber as well as for concentration, temperature, and pH level of the solution.

ASTM B117 salt spray test itself does not set a required duration for exposure; other specifications or governing standards typically specify the number of hours. Alternatively, in the absence of a governing specification, the client may specify the duration.

Result: ASTM B117 does not specify any required post-exposure assessments other than an immediate visual examination of test specimens. Again, other specifications or governing standards typically specify post-exposure assessments (e.g., ASTM D1654 or ASTM D610 for evaluating the degree of rusting).