PURPOSE: Section 280.050 states that the director shall promulgate rules to establish standards for preservatives used in the treatment of timber products. This rule establishes these standards to be used by anyone selling or offering for sale treated timber products in the state of Missouri.

Editor’s Note: The secretary of state has determined that the publication of this rule in its entirety would be unduly cumbersome or expensive. The entire text of the material referenced has been filed with the secretary of state. This material may be found at the Office of the Secretary of State or at the headquarters of the agency and is available to any interested person at a cost established by state law.

1. (1) The preservatives and preservative solution used shall meet the American Wood Preservers’ Association (AWPA) Standard P- Preservatives, as published in the AWPA Book of Standards (1985).

2. (2) Standards for Treatment of Coniferous, Softwood Species. The requirements for retention and penetration of preservatives used shall not be less than the American Wood Preservers’ Association Standards except that—

   1. (A) For ponderosa pine, red pine and southern yellow pine wood for farm use under standard C16, the minimum net retention levels of copper naphthenate shall be 0.04 pounds per cubic foot copper as metal for above ground use and 0.06 pounds per cubic foot copper as metal for ground contact use. (The copper naphthenate solution used for the treatment of wood products under these standards shall be in conformance to AWPA standard P8 as required under section
3. (1) of this rule.) All other requirements under AWPA standard C16 shall apply. This section shall expire when AWPA C16 standards for copper naphthenate are established and thus the AWPA standards will take precedence.

4. (3) Standards for Treatment of Deciduous, Hardwood Species. The requirement for retention and penetration of preservatives used shall not be less than the AWPA Standard except that—

   1. (A) For standard C2 the minimum net retention for oil-borne pentachlorophenol in the treatment of hardwoods, other than white oak, shall be 0.20 pounds of active ingredient per cubic foot or equal to 4.0 pounds of five percent (5%) solution. This standard shall become effective April 1, 1988. White oak shall be treated to refusal;
   2. (B) For standard C2 the minimum net retention for water-borne copper chromated arsenate in the treatment of hardwoods, other than the white oak, shall be 0.264 pounds of active ingredient per cubic foot if treated under AWPA ground contact standards or 0.25 pounds of active ingredient per cubic foot if treated under AWPA above ground standards. White oak shall be treated to refusal;
   3. (C) For standard C2 the minimum net retention for copper naphthenate in the treatment of hardwoods, other than white oak, shall be 0.033 pounds per cubic foot copper as metal. White oak shall be treated to refusal;

   4. (D) Effective April 1, 1988, all hardwoods, four inches (4") and greater in thickness, and treated according to subsections (3)(A)–(C) or up to the levels of AWPA standards C2, shall be labeled with a tag as follows:

      1. 1. Hardwoods listed in the AWPA man-

ual shall be labeled with a tag stating the percentage of AWPA ground contact or above ground contact retention level guaranteed and a statement of treatment to refusal for white oak. For example, a mixed bundle of white and red oak timbers, five inches (5") in thickness and greater, treated with a five percent (5%) solution of pentachlorophenol to 0.20 pounds of active ingredient per cubic foot, for ground contact, shall be tagged “Treated to 66% of AWPA Ground Contact Standards. White Oak Treated to Refusal.” Furthermore, the same mixed bundle of white and red oak timbers, treated under the same conditions to 0.25 pounds of active ingredient per cubic foot could also be tagged, “Treated to 100% of AWPA Above Ground Contact Standards. White Oak Treated to Refusal;”

1. 2. Hardwoods not listed in the AWPA

manual shall be labeled “Treated with a wood preservative but not recommended for structural purposes;” and 2 CSR 70-40

1. 3. All products as defined by this rule

shall be labeled with a tag in accordance to the following requirements:

1. A. Tags shall remain attached at each

point of sale and may only be removed by the final purchaser;

1. B. Each tag shall be placed on the sur-

face of each product so that it is readily visible to the purchaser;

1. C. Each tag shall be legible;
2. D. Tags shall bear the required infor-

mation in print of not less than ten (10)-point type;

1. E. Tags shall be constructed of water

resistant material; and

1. F. Tags shall have minimum dimen-

sions of one inch (1") in width and two inches (2") in length;

1. (E) For the treatment of hardwood posts, other than white oak, the minimum net retention for oil-borne pentachlorophenol shall not be less than 0.20 pounds of active ingredient per cubic foot or equal to 4.00 pounds of five percent (5%) solution. White oak posts shall be treated to refusal;
2. (F) For standard C2 the minimum net retention levels for copper naphthenate, except as modified in subsection (3)(C), in the treatment of hardwood species, other than white oak, shall be 0.04 pounds per cubic foot copper as metal for above ground use and 0.05 pounds per cubic foot copper as metal for ground contact use. White oak shall be treated to refusal. (The copper naphthenate solution used for treatment of wood products under these standards shall be in conformance to AWPA standard P8 as required under section (1) of this rule.) All other requirements under AWPA standard C2 shall apply. This subsection shall expire when AWPA C2 standards for copper naphthenate are established and thus the AWPA standards will take precedence; or
3. (G) For the treatment of hardwood posts, other than white oak, the minimum net retention for copper naphthenate shall be 0.033 pounds per cubic foot copper as metal. White oak posts shall be treated to refusal. (The copper naphthenate solution used for the treatment of wood products under these standards shall be in conformance to AWPA standard P8 as required under section (1) of this rule.)

1. (4) Other Treatment Standards. All other standards for treatment of timber or timber products with preservatives not covered by 2 CSR 70-40.015(2)(A) and (3)(A)–(G) shall not be less than the AWPA specifications.

AUTHORITY: section 280.050, RSMo 1986.* Original rule filed Oct. 10, 1980, effective Feb. 1, 1981. Amended: Filed Sept. 15, 1984, effective Jan. 2, 1985. Amended: Filed Dec. 16, 1985, effective March 13, 1986. Amended: Filed March 14, 1986, effective June 16, 1986. Amended: Filed March 18, 1987, effective April 1, 1988. Amended: Filed Jan. 12, 1990, effective April 16, 1990. *Original authority: 280.050, RSMo 1961, amended 1979, 1984, 1993, 1995.