Reference method for measuring emissions of nitrogen oxides from stationary sources: chapter 7
7 Safety precautions
7.1 The glass sample collection flask, which is evacuated during the sampling procedure, must be covered with tape or foamed plastic to avoid injury in case of implosion or breakage.
7.2 The fuming sulphuric acid used in preparing the phenol-disulphonic acid reagent is highly corrosive and fumes in moist air. Protective gloves, apron and face shield should be worn and the reagent preparation carried out in a hood.
7.3 Concentrated acids and bases are used throughout the laboratory procedure. Care should be used when adding them to other solutions to avoid overheating and skin contact.
7.4 Phenol is absorbed rapidly through the skin; exercise extreme caution during handling.