Quick Reference Values
Minimum Copper Sulphate (as CuSO4.5H2O) content23.5% by mass
Maximum Copper Sulphate (as CuSO4.5H2O) content26.5% by mass
Minimum Sodium Dichromate (as Na2Cr2O7.2H2O) content38.0% by mass
Maximum Sodium Dichromate (as Na2Cr2O7.2H2O) content42.0% by mass
Minimum Boric Acid (as H3BO3) content13.5% by mass
Maximum Boric Acid (as H3BO3) content16.5% by mass
pH of 2.5% treating solution2.5 to 3.5
Maximum sludging in 5% solution0.5% by volume
Practical Notes
CCB is a water-based preservative; timber must be adequately dried after treatment to prevent warping and ensure dimensional stability.
Strict adherence to safety protocols, including use of appropriate Personal Protective Equipment (PPE), is essential when handling the preservative concentrate and treated wood due to the toxicity of chromium and copper.
The effectiveness of treatment is determined by the penetration and net dry salt retention achieved, which should be specified and checked as per IS 401.