Why chlorine fastness is carried out for dyed goods?
A. Drinking water contains 1 ppm of activated chlorine and swimming pool water contains 5 ppm of activated chlorine, which is used for killing bacteria for disinfection. This water can cause discoloration and fading when it comes into contact with the dyed material. This is due to oxidation caused by active chlorine. This problem occurs more in cotton material as it readily absorbs active chlorine. Tests for colourfastness to chlorinated water include JIS 0084 (Strong test: 20 ppm, weak test: 10 ppm) and ISO 105 – E03 (available chlorine contains 20 ppm), both of which are widely used).
