This European Standard specifies tolerances, flatness, edgework, fragmentation and physical and mechanical characteristics of monolithic flat thermally toughened alkaline earth silicate safety glass for use in buildings. Information on curved thermally toughened alkaline earth silicate safety glass is given in Annex A, but this product does not form part of this European Standard. Other requirements, not specified in this European Standard, can apply to thermally toughened alkaline earth silicate safety glass which is incorporated into assemblies, e. g. laminated glass or insulating units, or undergo an additional treatment, e. g. coating. The additional requirements are specified in the appropriate product standard. Thermally toughened alkaline earth silicate safety glass, in this case, does not lose its mechanical or thermal characteristics.