scope:

This International Standard specifies flame emission spectrometric (FES) and flame atomic absorption spectrometric (FAAS) methods for determining the amounts of alkali metal oxides released from the surfaces of glassware when subjected to attack by an aqueous solution of hydrochloric acid at 100 ° C. The amount of alkali metal oxides determined is a measure of the acid resistance of the glass. This International Standard applies to pieces of glass, preferably flat but, if necessary, curved, cut from articles of laboratory glassware, from components of glass plant, pipeline or fittings or from any other articles used for purposes which may be described as "chemical". The acid resistance of glass "as delivered", i.e. the acid resistance of the original fire-polished surfaces, may be determined when the surface area of the cut and smoothed edges does not exceed 10% of the total surface area of the sample. The acid resistance of the glass "as a material" may be determined when the original surface has been removed by the hydrofluoric acid treatment described in 7.3. This preliminary acid treatment shall be applied to all samples of borosilicate glass 3.3 taken from components of glass plant, pipeline or fittings. The distinction between the acid resistance of glass "as delivered" and "as a material" may be of importance in cases where articles have been given a surface treatment during or after production.