Wood preservation facilities, copper azole : chapter H-1
Table of Contents
- 1. Production and Use
- 2. Physical and Chemical Properties
- 3. Environmental Effects
- 4. Human Health Concerns
- 5. Description of Preservative Application and Potential Chemical Discharges
- 6. Protection of Personnel
- 7. Design Recommendations
- 8. Operational Recommendations
- 9. Waste, Process Emissions and Disposal
- 10. Environmental and Workplace Monitoring
- 11. Transportation of CA-B and its Wastes
- 12. Environmental Emergency Notification and Contingency Planning
- 13. References
1. Production and Use
Copper azole (CA-B) is a water-borne formulation that is delivered in concentrate form to wood preservation facilities. Copper azole was originally formulated in the mid 1980s in Europe to meet the demand of consumers requesting an alternative wood preservative. Variants of this formulation have been in commercial production in more than 20 countries worldwide. The CA-B used in North America is CA-B type B (1)
The CA-B preservative is shipped to wood preservation facilities as a premixed concentrated solution that is diluted to working strength by adding a known quantity of water in a mix tank. The preservative is shipped to wood preservation facilities as a concentrate by tanker truck or totes.
CA-B is suited for treatment of refractory wood species and for all commercially used species. Water-based preservatives like CA-B leave wood with a clean, paintable surface after they dry (2). Copper azole is for use in the pressure treatment of wood products for residential and commercial use. It is not currently registered for use in saltwater marine immersion applications. CA-B overview of its uses is summarized in Table 1.
CA-B and other preservatives such as chromated copper arsenate (CCA) are incompatible and could cause chemical problems if used in a single treatment system. It is therefore not recommended that CA-B be used in the same cylinder as other preservative systems, such as CCA, as an ongoing practice. CA-B solutions are basic in pH whereas CCA, for example, is acidic. If a switch from one preservative to another is unavoidable, the situation would dictate complete flushing of one preservative from the cylinder, piping and pumps, and all sumps and collection areas before introduction of the other preservative.