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.
CCA treatment produced shallower preservative penetration than did ACZA for wood from both of the drying cycles (Table 4).
Average preservative penetration of conventionally dried boards treated with ACZA was more than double the required depth, and 83 percent of the boards met the required 10-mm penetration.
Treatment of posts with ACZA
produced markedly better preservative penetration.
The surfaces of the samples treated with ACZA
were strongly colored blue-green .
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.
Treating solutions of ACZA
and ACQ-B were also prepared by dil uting concentrates with deionized water, but the concentration of ammonia in each treating solution was also adjusted to a multiple of the a.