| abstract |
Indicator inks to show the progress of sterilisation with ethylene oxide, consist of (A) hexamethylene tetramine, (B) a conjugated basic dye and (C) water or hydrophilic organic solvent. Satisfactory sterilisation, e.g. of medical instruments of rubber, platics, glass, etc., is shown by bleaching or discoloration of the ink, due to strongly basic substance produced by reaction of ethylene oxide with (A). The indicator bands or cards are not discoloured by exposure to moisture or ammonia before use. |