What are the active components of CCB wood preservative?

The active components are Copper Sulphate, Sodium Dichromate, and Boric Acid, with their mass percentages specified in Table 1.

What is the required pH for a CCB treating solution?

The pH of a 2.5 percent solution of the preservative in water should be between 2.5 and 3.5 (Clause 3.1).

Is CCB preservative suitable for timber in contact with the ground?

Yes, when applied to achieve the required retention and penetration levels as specified in IS 401, CCB treated timber is suitable for ground contact and exterior applications.

In what form is CCB preservative supplied?

It is supplied as a homogeneous powder or paste, which is then dissolved in water to form the treating solution (Clause 3.2).

IS 10013

: 2000

water-soluble type wood preservatives, Part 2: Copper-chrome-arsenic (CCA) wood preservative

CurrentSpecializedSpecificationBIMMaterials Science · Timber and Timber Stores

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This standard specifies the requirements for three types of Copper-Chrome-Arsenic (CCA) water-soluble wood preservatives. It details the chemical composition, preparation of treating solutions, packing/marking guidelines, and includes test methods for determining the percentage of active components.

water-soluble type wood preservatives, Part 2: Copper-chrome-arsenic (CCA) wood preservative

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

Key Formulas

Mass of Copper, percent = (V x N x 6.35) / M — Appendix A, for copper determination

Mass of Hexavalent Chromium, percent = (V x N x 1.733) / M — Appendix B, for chromium determination

Mass of Arsenic, percent = (V x N x 3.746) / M — Appendix C, for arsenic determination

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.