ASTM B117 vs ISO 9227 vs JIS Z 2371: Which Salt Spray Standard Should You Use?

ASTM B117, ISO 9227 and JIS Z 2371 all describe a neutral salt spray (NSS) test: a 5% sodium chloride solution is atomised into a closed chamber held at a controlled temperature, and test samples are exposed to the resulting salt fog for a set duration.

Because the core method is so similar, a well-built salt spray chamber that meets ASTM B117 chamber and control requirements will generally also satisfy ISO 9227 and JIS Z 2371 neutral salt spray testing, since all three specify comparable chamber temperature (35°C), solution concentration and pH ranges. This is why most commercial chambers, including the models UMA Industries manufactures, are built and labelled as ASTM B117 / ISO 9227 / JIS Z 2371 compliant rather than as a single-standard machine.

ASTM B117 is published by ASTM International and is the most widely referenced salt spray standard in Indian manufacturing, especially for customers supplying to US OEMs or following American quality frameworks. It defines the apparatus, salt solution preparation, temperature control and general operating procedure for the neutral salt spray test, but it does not define pass/fail corrosion criteria — that's left to the product specification that calls out ASTM B117.

ISO 9227 is the international equivalent, commonly required by European customers and companies working to ISO-based quality systems. It covers neutral salt spray (NSS) as well as acetic acid salt spray (AASS) and copper-accelerated acetic acid salt spray (CASS) variants, which are used for more aggressive testing of decorative coatings like copper-nickel-chromium plating.

If your product needs to be tested under AASS or CASS conditions in addition to plain NSS, confirm that the chamber's temperature control and solution delivery system explicitly support those modes.

JIS Z 2371 is the Japanese Industrial Standard version of the same test, commonly specified by Japanese automotive and electronics OEMs or their Indian supply chain. Procedurally it is very close to ASTM B117 and ISO 9227 NSS testing, with only minor differences in documentation and reporting conventions.

In practice, most buyers don't choose a standard in isolation — it is dictated by a customer drawing, an export requirement, or an internal quality manual. Use this quick checklist:

Because the underlying chamber technology overlaps so heavily, it's rarely worth buying single-standard equipment. UMA Industries' Basic, ASTM B117 / ISO 9227 and Graphical Touch Screen chamber ranges are all built to support ASTM B117, ISO 9227 and JIS Z 2371 neutral salt spray testing, so the choice between models comes down to chamber capacity, automation level and reporting needs rather than standard compatibility.