CCA and CCB

Copper Chrome Arsenic (CCA): water-borne fixing type:
It is a heavy duty broad spectrum preservative patented as AsCu; the
formulation consists of arsenic pentoxide and copper sulphate with
sodium dichromate as the fixative in the ratio 1:3:4. CCA has been found
to provide protection for 50 years or more. Due to the arsenic component
only exterior applications are recommended. Though no study has
revealed adverse effects due to exposure to treated products, it must
nevertheless be handled with special care.

Copper Chrome Boron (CCB): water-borne fixing type:
It is a broad spectrum preservative containing boric acid, copper sulphate
and sodium dichromate in the ratio 1.5:3:4. It is a good alternative to
CCA but less effective with a lower degree of fixation, of the Boron
component.