Certification and validation of products may sound the same, but there are significant differences. Both evaluate a product against the requirements of an ANSI/NSF standard. While validation is a one-time event, certification is an ongoing process.

After initial certification of the product to the standard, NSF conducts annual audits to ensure that the manufacturer is making the product in the same way, with the same materials. Specifics such as processing oils and potential manufacturing facility contamination are detailed. There is also a recertification process, where products are obtained either from the manufacturer or the field and tested to the standard, certifying that the product still meets the standard's rigorous requirements.

On an international level, NSF certification enables manufacturers to gain easier access to foreign markets. Third-party certification is much more recognized by international regulators because of the added credibility of testing and follow-up audits.