Treatment Chemicals

Copper Azole Treating

For most treated wood applications we use CA-type C , which is a major copper based wood preservative that has come into wide use in Canada, the US, Europe, Japan and Australia following restrictions on CCA. Its use is governed by national and international standards, which determine the volume of preservative uptake required for a specific end use.

Copper azole is a dissolved copper preservative augmented by two organic azole co-biocides which are also used to protect food crops. The azole co-biocide yields a product that is effective at lower retentions than required for some other arsenic free preservatives. The general appearance of wood treated with copper azole preservative is similar to CCA with a green color.

The AWPA standard retention for Type C copper azole, denoted as CA-C, has been introduced under the Wolmanized brand. The AWPA standard retention for CA-C is 0.06 lb/ft3 for above ground applications and 0.15 lb/ft3 for ground contact applications. It is approved for all outdoor applications, both above ground or ground contact.

We can provide CA-C lumber and timbers or we can provide TSO with this safe effective treatment.

Chromated Copper Arsenate

CCA is a very effective and time tested preservative that has been used for lumber and timber treatment since the mid-1930s. It is a mix of chromium, copper and copper arsenate oxide, and is recognizable for the greenish tint it imparts to the treated wood. CCA was invented in 1933 and was awarded its first patent (British) in 1934. It was a safer and more effective treatment than the Creosote and Penta that were used prior, and replaced them in nearly all applications.

CCA is known by many trade names and is the world’s most widely used wood preservative. It is manufactured to national and international standards depending on the country of intended use, including AWPA P23-10 for the USA and SANS 673 for South Africa, and each manufacturer needs to comply with these standards.

A number of countries have reviewed CCA during recent years and have restricted its use in residential situations. These restrictions were a precautionary move due to public pressure after the publication of some studies suggesting that CCA could pose a risk to children. Subsequent studies found this not to be the case. However, in response to the pressures at the time, the wood preservation industry in 2003 in the USA and Canada volunteered not to use CCA for the treatment of residential lumber. On 31 December 2003 the production of CCA-treated wood for such applications became a violation of the manufacturers’ labels approved by the United States Environmental Protection Agency.

Today CCA is restricted for use only in industrial or agricultural applications such as:

CCA Utility Poles
Foundation Piling
Highway Uses
Salt Water Marine Treated Wood
Permanent Wood Foundations
Agricultural Timbers & Poles
Plywood
And a few other specialized uses.

Call us to discuss your use and we can tell you if CCA use is allowed.

For more information go to: http://www.koppersperformancechemicals.com/cca/