ANNEXDETERMINATION OF DICHLOROMETHANE AND 1,1,1-TRICHLOROETHANE
IDENTIFICATION AND DETERMINATION OF MERCAPTOACETIC ACID IN HAIR-WAVING, HAIR-STRAIGHTENING AND DEPILATORY PRODUCTS
4.IDENTIFICATION
4.1.Identification by spot tests
4.1.2.Procedure
4.1.2.3.Characterization of sulphites by the formation of sulphur dioxide upon acidification
Proceed as described in 4.1.2.2. Bring to the boil. The sulphur dioxide is recognizable by its smell and by its reducing properties in respect, for example, of permanganate ions.