Replace the first paragraph by: "This document specifies a horizontal reference method for the determination of emissions of regulated dangerous substances from construction products into indoor air. This method is applicable to volatile organic compounds, semi-volatile organic compounds, very volatile aldehydes and ammonia. It is based on the use of a test chamber and subsequent analysis of the organic compounds by GC-MS, HPLC, and for ammonia, subsequent analysis by spectrophotometric methods or any equivalent analytical methods (such as ion chromatography and ammonium specific electrode).".