International Journal of Interdisciplinary Research
From: Indicator washcloth for detecting alkaline washing solutions to prevent dermatitis patients and babies from skin irritation
Type of indicator washcloth
pK a at 4 °C
pK a at 20 °C
pK a at 40 °C
IW1 (Strongly coloured)
7.32
7.31
7.24
IW2 (washed 80 times)
7.28
7.42
7.12
IW4 (Weakly coloured)
7.58
7.63
7.57