WHO accredits laboratories that are qualified to test one or several categories of products seeking prequalification. Accredited laboratories must also be able to carry out at least one of three types of product verification procedures: type-examination, independent type testing, or full quality assurance.
WHO only accredits laboratories that can demonstrate that they conform to international standards or codes of practice. The laboratory must be able to demonstrate to a competent third-party accreditation body that it meets international requirements.
At the current time only laboratories accredited by WHO can be selected for testing products for WHO prequalification. In future, WHO plans to open up accreditation to other laboratories that meet WHO accreditation criteria.