摘要 |
An indicator which is used for indicating the completion of a sterilization process in which an article to be sterilized is exposed to formaldehyde vapor either dry or mixed with steam. The indicator comprises a mixture of preferably two amino acids and a pH indicator impregnated in a paper carrier. The amino acids and pH indicator are such that the change point of the pH indicator lies within the range of the change of pH value of the amino acid mix which occurs on exposure of the amino acids to formaldehyde vapor. |