Making cobalt chloride paper
Read our standard health & safety guidance
Refer to CLEAPSS Hazcard 25 and CLEAPSS Recipe Card 46.
a Dissolve 5 g of hydrated cobalt(II) chloride in 100 cm3 of water (solution is Toxic).
b Soak filter paper in this solution, drain and dry in an oven (set at no more that 100°C), so that it is a definite blue colour.
c The filter paper can be cut into small strips and stored in a desiccator with dry silica gel.
Cobalt chloride is Toxic and a Danger to the environment and May cause sensitisation. The indicator papers should be handled as little as possible and hands washed after use.
Health and safety checked, November 2007
Updated 3 Dec 2007
