• ensure the credibility of the BASTA system among suppliers and users
• feed back experience from the practical application of the system to the continued development of the BASTA system. With the aim of obtaining clear and robust terms of qualification and uniform assessments in qualification.

The validation function is based on an audit being made of a selection of the participating suppliers to check the supplier´s capacity and ability to fulfil the terms of qualification by examining:

• Organisation, delegation of responsibility
• Assured access to the necessary expertise
• Document management routine for construction products
• The supplier´s marketing of the BASTA-registration according to the terms of agreement
• Basis of qualification for a selection of registered construction products

Auditors are attached to the BASTA system through annual agreements. These auditors are to be impartial in their work in relation to the object of the audit. The selection is made so that the group of auditors together provides the necessary broad expertise. Each individual auditor has to firstly meet all applicable requirements for basic competence and secondly have experience of practical work in one or more of a number of areas of specialist expertise. In addition, a number of ethical rules apply, which are the same as those drawn up by the Association of Swedish Environmental Auditors (MIS).