Organization and Use of Standards
In the AWPA Book of Standards, the different types of Standards are presented in a logical order. First, the Use Category System Standards are shown, followed by Preservative Standards. Next, Analytical, Miscellaneous, and Evaluation methods are presented. The letters “AWPA”, the designation of its standards (e.g. U1, P25), Use Categories (e.g. UC3B, UC4A), and other AWPA nomenclature are trademarks of the American Wood Protection Association. When referring to or marking products using an AWPA Standard or associated nomenclature, that product must meet all applicable requirements of that Standard. Although these trademarks are owned by AWPA, a royalty-free license is granted to use them if, and only if, the product fully meets or exceeds the requirements of the applicable AWPA Standard.
Use Category System Standards (U1 & T1)
The Use Category System Standards are the culmination of many years’ efforts to simplify the specification of treated wood products. Under the previously used Commodity Standards (C Standards) the user would specify a different Standard for each type of product. With 36 different C Standards, there was a significant degree of error in product specifications. The Use Category System took all of the information from the C Standards, and put the information for users into Standard U1, and the information for manufacturers (primarily wood treaters) in Standard T1.
AWPA Standard U1 is the primary standard for specifiers, such as architects and engineers, but also for end users and building code officials. This Standard contains the information needed by specifiers in order to select a product that best suits their needs. It begins by defining the various Use Categories (UC), which are the service conditions to which wood and wood-based products are exposed. Section 3 of Standard U1 provides a guide to the different types of products used and lists recommended Use Categories. Sections 4 and 5 list preservatives and wood species found in the Standard. The Commodity Specifications contain the actual specifications for each type of product in the various Use Categories, with retention values for each species/preservative combination and any special requirements which may apply. The AWPA Use Category System and the various Use Categories (UC) described in AWPA Standard U1 are trademarks of the American Wood Protection Association, and a royalty-free license is granted to use the UC mark if, and only if, the product meets or exceeds the requirements of AWPA Standard U1.
Standard T1 contains the requirements for manufacturing products in accordance with Standard U1. Limitations for the different processes used to protect the wood, such as temperature and pressure limitations, incising requirements, and many other parameters are found in this Standard.
Preservatives/Protectants Standards (P)
There are several types of preservatives/protectants described in AWPA Standards. The first type is creosote-based systems, which include creosote itself, as well as the creosote solutions and creosote-petroleum solutions. There are also oilborne preservatives, which are typically an active ingredient, such as pentachlorophenol or copper naphthenate, dissolved in a hydrocarbon solvent, which acts as a carrier to transport the active ingredient(s) deep into the wood fiber. In a similar manner, waterborne preservative systems consist of an active ingredient dissolved or dispersed in an aqueous solution, where water is the primary carrier for the active ingredient(s). Common waterborne preservative systems include, but are not limited to CCA, CA, ACQ, EL2 and PTI.
Hydrocarbon Solvent Standards (HS)
These Standards provide the specifications for several hydrocarbon solvents used as carriers in organic (carbon-based) preservative systems, such as pentachlorophenol or copper naphthenate.
Analysis Method Standards (A)
These methods are useful for determining conformance of products to other AWPA Standards and specify the acceptable procedures for testing preservatives. These tests encompass methods for the determination of physical properties, chemical composition, purity of preservatives, and the results of treatment; i.e., preservative retention and penetration in the treated product.
Miscellaneous Standards (M)
These AWPA Standards are indeed miscellaneous, covering many different subjects which do not fit into other categories of Standards. A guide for the specification of treated wood products is found in Standard M1. Please note that this document is for guidance only and is not to be construed as a manufacturing requirement. Inspection requirements and quality control procedures are found in Standards M2, M3, M19, M21, M22 M23, and M25. For information on the proper use and care of treated wood products, Standard M4 provides the requirements for handling and post-fabrication procedures. When products must be branded (e.g., utility poles and piling) the requirements in Standard M6 apply. Standard M13 is a guideline document for the development of a utility pole maintenance program and is geared to the needs of utility personnel.
Evaluation Standards (E)
These research and development methods encompass laboratory and field tests for evaluation of the biological permanence, leaching and corrosion, and overall efficacy. Many of these methods are used to develop data required for submission to AWPA’s Technical Committees for adoption of a preservative system in AWPA’s Standards. For more information on the requirements for testing new wood preservative systems, consult the Appendices to the AWPA Technical Committee Regulations.