3rd February 2012, 07:38 PM
If the indicator is cobalt chloride then, if you bathe in it for a year and eat a kilo every day, you might get a wart! Seriously, cobalt chloride is Group 2B listed as possibly carcinogenic to humans by the International Agency for Research on Cancer. You should use orange indicating silica gel, which turns a dark green when damp. Better still, use cobalt free indicator strips - especially if you are using stewart boxes for storing your metals.