These years-to-failure estimates bode well for the durability of wood products treated to standard retentions with the current ACZA formulation, considering that the standard retentions for critical members are greater than those evaluated in the current study.
88 (a) ACA = ammoniacal copper arsenate; ACZA = ammoniacal copper zinc arsenate; CCA = chromated copper arsenate (type A, B, or C).
Migration of metals from Douglas-fir lumber treated with ACZA
or pentachlorophenol using best management practices: Preliminary tests.
Figure 3 (left) shows a sample with both gribble and shipworm damage whereas Figure 3 (right) shows the comparative condition of PSL samples after treatment with CCA or ACZA to retentions greater than 16 kg/[m.
The Douglas-fir samples treated with higher retentions of ACZA displayed significant weight loss at a level of approximately 10 percent.
1 mm for incised sections treated with ACZA (Table 1).
The percentage of sections meeting the minimum penetration level ranged from 53 percent for incised boards treated with CU-8 to 98 percent for incised boards treated with ACZA and CCA?
According to Micklewright (1999) and the more recent 2000 Southern Forest Products Association (SFPA) treated wood survey (Wade and Mason 2002) CCA (and small amounts of ACZA
in the West and Midwest) are used to protect 80 percent of the lumber that is preservative treated for residential applications.
cycle consisted of a 2-hour initial steaming period at 115 [degrees]C followed by a 30-minute vacuum at 87 kPa.
treatment, the wood was steamed for 2 hours (11 7[degrees]C), then a vacuum was drawn for 30 minutes (66 cm Hg) and treating solution (1.
An additional 16 panels were treated with ACZA
prepared from an 18 percent commercial oxide concentrate.
These products are derived from ammoniacal copper arsenate (ACA), developed in the United States in the 1930s, and updated as ACZA
in the early 1980s.