The NF mark affixed to a product guarantees that it complies with the relevant standards and, where applicable, additional technical specifications requested by the market. The characteristics set out by CSTB (Centre Scientifique et Technique du bâtiment) are specified in the specifications referred to as the certification reference system, drawn up in consultation with parties concerned. The certification rules concerning acrylic sheets bear the number 116. They can be downloaded from the website evaluation.cstb.fr.
CSTB tests the products and audits the companies within the scope of this certification.