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Laboratory bioassay on the termiticidal efficacy of two ACQ formulations
1999 - IRG/WP 99-30199
The termiticidal efficacy of two ammoniacal copper quaternary ammonium formulations (ACQ) was evaluated in a laboratory bioassay using two species of subterranean termites, Mastotermes darwiniensis Froggatt and Coptotermes acinaciformis (Froggatt). Five retentions (1.0, 2.0, 4.0, 6.0 and 8.0 kg/m3 of active ingredient) of each ACQ formulation (MitrexACQ and ACQ97) were assessed in sapwood specimens of the softwood Pinus radiata D. Don and compared with the same retentions of the conventional benchmark preservative CCA (Tanalith C). All specimens (including controls) were subjected to an artificial weathering schedule prior to the bioassay. Under the conditions of the laboratory bioassay, both MitrexACQ and ACQ97 showed considerable potential as water-borne preservatives for preventing significant attack of P. radiata sapwood from two of Australia's most economically significant species of termite. At each of the retentions tested, MitrexACQ and ACQ97 performed comparably or better than equivalent retentions of CCA.
J W Creffield, A F Preston, N Chew

Surface characteristics of wood treated with various AAC, ACQ and CCA formulations after weathering
1991 - IRG/WP 2369
Wood samples treated with various alkylammonium compounds (AACs) as well as ammoniacal copper quat (ACQ) and chromated copper arsenate (CCA) have been studied in accelerated weathering experiments. Microscopic examination of the surfaces of these samples after exposure in a weatherometer revealed several different changes. Samples treated with didecyldimethyl ammonium chloride (DDAC) show considerable latewood defibration and severe earlywood erosion, while ACQ and CCA treated samples are far less prone to surface weathering than AAC treatments as well as the untreated controls. FTIR spectral data of surface material removed from these samples correlated well with the observed surface defibration. It appears that lignin components are most affected by the weathering process. The AAC counterion and chain length of dialkyl quaternaries in AAC treatments appear to influence the weathering effect.
L Jin, K J Archer, A F Preston

Biological Performance of micronized copper wood preservative formulations in field and laboratory tests
2008 - IRG/WP 08-30488
Micronized Copper wood preservative formulations with different co-biocides were exposed to brown rot fungi in an 8-week AWPA E10 soil block decay test and two AWPA E7 ground-contact decay tests in Hawaii. The micronized copper formulations performed well against decay at or above the AWPA UC3 and UC4 retentions stipulated by the ICC-ES. Micronized copper preservatives performed comparably to a conventional ACQ reference preservative. In the soil block decay test, micronized copper azole (MCA) performed similarly to ACQ-D using three brown rot decay fungi. In a 40-month ground contact decay test, southern pine stakes treated with MCA, micronized copper quat (MCQ), and ACQ-D at or above the UC4A retentions performed similarly and each rated greater than 9.0 against decay.
G M Larkin, J Zhang, D L Richter, R J Ziobro, P E Laks

Tensile stress relaxation of wood impregnated in different ACQ formulations at various temperatures
2009 - IRG/WP 09-40456
The reactions between ammoniacal copper quat (ACQ) constituents and wood components were investigated by tensile stress relaxation approach. Small wood samples were stressed and impregnated in ACQ solutions with different formulation including the ethanolamine (MEA) to copper molar ratio, copper (as copper oxide) to quat (as DDAC) weight basis, treatment temperature and also the solution concentration, and during this period the stress relaxation curves were recorded. The effect of different parameters mentioned above on stress relaxation of wood was investigated by orthogonal experiment design (OED). From the stress relaxation curves, some information concerning the reactions between ACQ constituents and wood was obtained since the formation of chemical or physical bonding between ACQ and wood would both release the stress produced in wood and then accelerate the stress relaxation process. The results showed that the stress relaxes dramatically in the initial period and then change slightly even within a long period. There are two reaction mechanisms predicted from the slopes of the regression lines obtained from the double logarithmic plots of modulus f (t) versus time (t) in the initial period of stress relaxation, which are defined as Phase I and PhaseⅡ. They correspond to physical and chemical processes respectively. The molar ratio of Cu to MEA and treatment temperature take the significant effects on the rate of reaction on Phase I, while on Phase Ⅱ, the significant factor is only the treatment temperature based on the results of range and variance analysis. It reveals that although the competitions among ACQ constituents existed, the adsorption of copper is still the major reaction in the wood.
Lili Yu, Jinzhen Cao

Organic solvent preservatives. Essays on the ecotoxicology of new formulations
1991 - IRG/WP 3642
The knowledge on the ecotoxicological profile of wood preservatives become more and more important. The acute toxicity against aquatic organisms was examined for oil-borne preservatives, based on combinations of new fungicides (Tebuconazole, Propiconazole, Dichlofluanid) and insecticides (Permethrin, Cyfluthrin). These tests were conducted with fish, daphnia and algae. In principle the different formulations showed similar effects. The results of active ingredients and solvents confirmed the high sensitiveness of daphnia as test organisms. Criteria for hazards for the environment are presented and discussed.
H-W Wegen

Evaluation of new creosote formulations after extended exposures in fungal cellar tests and field plot tests
2000 - IRG/WP 00-30228
Although creosote, or coal tar creosote, has been the choice of preservative treatment for the railroad industry since the 1920s, exuding or "bleeding" on the surface of creosote-treated products has been one incentive for further enhancements in creosote production and utility (Crawford et al., 2000). To minimize this exuding problem, laboratories such as Koppers Industries Inc., USA, and Commonwealth Scientific and Industrial Research Organization (CSIRO), Division of Chemical and Wood Technology, Melbourne, Australia, have developed changes in processing of coal tar that produce distillates with fewer contaminants. This "clean distillate" is then used to formulate "clean creosote" as a preservative. These new, unique creosote formulations are being investigated as part of a program to enhance the use of regionally important wood species in the United States. Four retention levels of each of two new creosote formulations creosote, one pigment-emulsified creosote (PEC) and one creosote formulation that meets the AWPA Standard C2-95 for P1/P13 creosote (AWPA, 1995a), were applied to two softwood species and two hardwood species. Two laboratory procedures, the soil-block and fungal cellar tests (accelerated field simulator), were used to evaluate the four creosote formulations. These procedures characterized the effectiveness of the wood preservatives. The soil-block tests were used to determine the minimum threshold level of the preservative necessary to inhibit decay by pure cultures of decay fungi. In general, the soil block tests showed there was little difference in the ability of the four creosote formulations to prevent decay at the three highest retention levels as summarized in a previous report by Crawford and DeGroot (1996). The soil-block tests will not be discussed in this report. Fungal cellar tests expose treated wood to mixtures of soil-borne fungi that promote accelerated attack. Crawford and DeGroot (1996) discussed the evaluation of the creosote formulations after 17 months of exposure in the USDA Forest Service, Forest Products Laboratory (FPL), fungal cellar. At that point in time data from the fungal cellar tests showed that softwoods are protected better than hardwoods for all four formulations of creosote tested. This report will discuss exposure of the fungal cellar stakes upto 36 months. In addition, field stake tests are being used to verify service life of the new creosote formulations in vivo. Results from accelerated tests are indicative of field performance, but the correlation between laboratory and field results is still being investigated. Field stake tests are regarded as critical, long-term evaluations that provide results most directly related to the performance of treated products in service. In this study, we report on the performance of the creosote formulations after five years of exposure in field tests.
D M Crawford, P K Lebow, R C De Groot

Current techniques for screening initial formulations against Basidiomycetes and soft rot
1978 - IRG/WP 2103
J D Thornton, H Greaves

In-ground performance of two formulations of chlorothalonil after five years of exposure at three test sites in Australia
1996 - IRG/WP 96-30101
Sapwood specimens of Pinus radiata D. Don and Eucalyptus regnans F. Muell. were each treated to three retentions of each of two preservative formulations (chlorothalonil in oil; chlorothalonil plus chlorpyrifos in oil) and installed in-ground at three field test sites in Australia. Specimens were treated with each formulation to achieve 3.2, 6.4 and 12.8 kg/m³ of chlorothalonil a.i. and 3.2 + 0.2, 6.4 + 0.4 and 12.8 + 0.8 kg/m³ of chlorothalonil plus chlorpyrifos a.i. For comparison, specimens of each timber species, treated to a commercial in-ground retention of a copper-chromium-arsenic (CCA) formulation, were also installed. Treated specimens (including controls) have been rated for their condition annually for attack by subterranean termites and fungal decay using a scale ranging from 4 (sound) down to 0 (failed). After five years of exposure, mean termite and decay scores for replicate test specimens at each site reveal that the performance of all three retentions of each formulation, particularly the two highest retentions, is comparable to CCA.
J W Creffield, T L Woods, N Chew

Progress towards controlling soft rot of treated hardwood poles in Australia
1977 - IRG/WP 289
H Greaves

The Effect of Heat on the Retention of Ammoniacal Copper Quat (ACQ-AB) onto Scots Pine (Pinus Sylvestris L.) Wood
2008 - IRG/WP 08-40390
In this study, the sapwood of Scots pine (Pinus sylvestris L.) were treated with ammonical copper quat type (ACQ-AB), which is one of the environmentally friendly wood preservatives, by using soaking method as a functions of various temperatures and time. The results indicated that the retention behaviour of ACQ onto the wood was considerably affected by temperature of ACQ solution and treatment time.
M Hakki Alma, A Mukremin Kara

Chapter 6 - Preservatives of bamboo
2007 - IRG/WP 07-10635-06
Almost all currently available oil-borne, water-borne and compound types of preservatives suitable for the preservation of bamboo or wood have been described along with their classifications, applications, formulations, merits and demerits, history of invention or discovery and development. The preservatives suitable for wood are also considered suitable for bamboo.
A K Lahiry

Inorganic wood preservative levels in soil near a noise barrier treated with different preservatives after 8 years in service
2005 - IRG/WP 05-50234
In March 1996 nine test sections of a noise barrier were installed near Stockholm Sweden. The test sections include untreated Scots pine, spruce and larch and Scots pine, treated with different wood preservatives. After 8 years in service, the untreated spruce, pine and larch boards in contact with the soil were significantly decayed, with an estimated service life of about 5-10 years, while the untreated wood above ground is stained but not visibly decayed. Some degradation was detected in wood in soil contact for some of the preserved pine sections treated to AB levels (i.e. use class 3, above ground). Soil samples were collected at three horizontal distances from the barriers (0, 7 and 14 cm) with the 7 cm sample representing the drip line under a protective wedge designed to keep water out of the joints. Samples were collected at two depths representing groundline and the depth of the barrier in the soil (7.5 – 13 cm) and directly under the barrier. Soil samples collected after 8 years showed highest contaminant levels close to the barrier and under the wedge dripline. Arsenic levels in some locations close to CCA treated panels exceeded Swedish and Canadian soil guidelines for agricultural use and copper levels were above residential/park guidelines for some locations near ACQ and Tanalith MCB treated panels.
P A Cooper, Y T Ung, M-L Edlund, J Jermer, O Söderström

Copper based water-borne preservatives: The biological performance of wood treated with various formulations
1987 - IRG/WP 3451
Wood samples treated with the various components of CCA preservative singly and in combination were tested against a soft rot organism, a copper tolerant brown rot organism and in soil burial both unleached and after leaching. The results suggest that, of the elements tested, fixed copper is essential for preventing soft rot attack and fixed arsenic is essential for preventing attack by a copper tolerant brown rot organism in leaching environments.
S M Gray, D J Dickinson

Field Test Results after Nine Years for CCA and ACQ Preservative-treated Wood Fixed in Different Climates
2003 - IRG/WP 03-30303
During assessment of the ground contact stakes in the Norwegian test field, we have frequently found that the first visual rot attack is in the zone of the stakes, where the stakes have been in contact with each other during the fixation. These parts are usually light green, caused by the lack of light during fixation, compared to the rest of the stake surface, which has a darker colour. To investigate if light on the stakes during fixation can affect the durability of the treated wood, we started a test in 1993. CCA and ACQ treated stakes were tested according to EN 252. The stakes were treated with two retentions of each salt. One according to the Nordic Class A (for ground contact i.e. hazard class 4) and one lower retention (25 % of the class A retention. This is even lower than the Nordic class AB (HC 3) retention). Before exposure they were fixed in 7 different climates: 1) Normal fixation = 60 % RH and 25 °C, light days, dark nights for 7 days, 2) Dark fixation = normal fixation without light for 7 days, 3) UV-light fixation = normal fixation with UV-light 24 hours for 7 days, 4) Hot fixation = 95 % RH and 90 °C for 2 hours, 5) Cold fixation = 50 % RH and 10 °C for 30 days, 6) Dry fixation = 10 % RH and 50 °C, for 24 hours, 7) Wrapped fixation = each stake packed in black plastic foil, 50 °C and without light for 24 hours. The colour of the ACQ stakes varied from light green to black, depending on the fixation climates. These different colours and the durability results after 5 years were reported at the 30th IRG meeting in 1999. The different fixation procedures give only small differences in durability/rot index after 9 years in field test. Hot, dry and wrapped fixations give ACQ a better durability than CCA in the Nordic class A retention. None of the ACQ stakes were rejected in the first 9 years, while the CCA stakes had a few rejected stakes after 8 and 9 years caused by sot-rot. For the low retention, ACQ gives a better durability than CCA for all fixation procedure, but both preservatives had several rejected stakes.
F G Evans

Potential toxicants for controlling soft rot in preservative treated hardwoods. Part 4: Evaluation of combined diffusion and toxicity
1979 - IRG/WP 2129
A large number of inorganic and organic preservatives were evaluated as potential soft rot control chemicals, by their degree of inhibition of fungal growth after allowing them to diffuse through a 6 mm thick wood slab. The tests were inoculated with wood powder from soft-rotted CCA treated poles. Pentachlorophenol was unable to diffuse quickly through the wood slab, although formulations with hexylene glycol showed some promise. Hydroxyisoxazole gave good results as did a number of other organic materials including "Busan 30", "Busan 52", "Permapruf T", sodium oxinate, sodium trichlorophenate, "Gloquat C", „Hyamine 1622", butyl icinol, and the commercial bandage materials "Osmoplast" and "Wolman pole bandage". Of the inorganic materials tested, good results were obtained with "Basilit BFB", with other Cu-F-B formulations including "Blue 7", and with fluoroborate and fluorosilicate preparations in general. Arsenates also showed some promise.
E W B Da Costa, O Collett

Leaching of inorganic wood preservatives – Investigating the relationship between leachability, dissociation characteristics and long-term leaching potential
2003 - IRG/WP 03-50199
Estimation of the leaching properties of preservative components is greatly affected by the leaching test method applied since not all methods equally consider the physical components responsible for leaching. These include: wetting of the wood and penetration of water (affected by dimensions, amount of end grain, permeability, duration and nature of water exposure); solution of preservative components into available moisture (affected by component solubility, wood moisture content, temperature, etc.); diffusion of components out of wood (affected by product dimensions, permeability, direction of movement, moisture content, temperature, nature of the diffusing species, etc.); and re-drying of the wood between moisture exposures. Aggressive leaching of finely ground wood provides a measure of the ultimate amounts of preservative compounds available for leaching while analysis of the equilibrium dissociation or solubility of components in free water in the wood provides information on their effective concentration which drives the diffusion process. Combining this information with a simple diffusion test should allow the estimation of potential risk from leaching over a wide range of specified conditions. In this paper, the leaching of several inorganic wood preservatives is compared and related to dissociation of preservatives within the wood structure and diffusion out of wood.
L Waldron, Y T Ung, P A Cooper

Disposal of Pressure Treated Wood in Construction and Demolition Debris Landfill
2005 - IRG/WP 05-50235
Pressure treated wood is often disposed in landfills in the US, very frequently in construction and demolition (C&D) debris landfills. C&D debris disposal facilities in many states are not equipped with liner systems to protect underlying groundwater. In this paper, issues associated with the disposal of metal-containing treated wood in C&D debris landfills are discussed. C&D debris landfills can be biological active systems, dominated by the activity of sulfate reducing bacteria. The leachate is characterized by relatively low biodegradable organic compound concentrations, high salt concentrations, a neutral pH, and a moderately to strongly reducing environment. Simulated landfills containing CCA-treated wood often show relatively high concentrations of As and Cr, but only minimal concentrations of Cu. Cu-based preservatives such as alkaline copper quaternary (ACQ) also show minimal copper leaching, suggesting that disposal of Cu-based wood preservatives posees minimal impact to groundwater from Cu leaching.
T G Townsend, B Dubey, J Jambeck, H M Solo-Gabriele

Marine performance of preservative treated Southern pine panels. Part 2: Exposure at Mourilyan Harbour, Queensland, Australia
2000 - IRG/WP 00-10337
Southern yellow pine panels treated with ACQ type B, ACQ type A, CCA type C, creosote, and copper naphthenate have been exposed at Mourilyan Harbour, north Queensland, Australia for almost 6 years. These panels have been inspected and rated for fouling and attack by Teredinid, Limnoria, Martesia, and Sphaeroma during this exposure. After 70 months exposure, overall performance of ACQ type B was equivalent to CCA type C at similar loadings, while ACQ type A did not perform as well. CCA and ACQ at 40 and 20 kg/m3 are performing similar to creosote at 430 and 200 kg/m3, respectively. The copper naphthenate treated panels did not perform as well as the ACQ panels at similar total copper loadings. Fouling of panels treated with ACQ was less than that found on CCA and creosote treated panels, but similar to that found on copper naphthenate treated panels exhibiting the same level of performance.
A R Zahora, A F Preston, K J Archer, S Kleinschmidt

Preliminary screening of diffusion formulations for the control of soft rot
1978 - IRG/WP 2104
We have an urgent need in Australia to develop in situ remedial treatments for the present population of in-service transmission poles. For various reasons we have opted for formulations which can be applied as bandage treatments and thus we are primarily concerned with assaying diffusable toxicants. Two basic approaches have been made: an assay of the formulation's toxicity; and a combination assay of the formulation's diffusibility and toxicity. Of the direct assay methods the filter-paper technique is the more rapid although with highly soluble formulations some leaching of toxicants will occur during the preparatory stages and probably during incubation also. Furthermore, filter papers are not strictly comparable to wood, and a modification we have considered is to use 'papers' prepared from mechanically beaten pulps rather than chemically degraded pulps. An additional modification would be to substitute veneers for filter papers, although this may give rise to surface concentration effects since the veneers could prove difficult to impregnate homogeneously. By far the most valuable technique for our own screening programme of potential toxicants to control soft rot in standing poles is the Petri dish/wood slab technique. While agar diffusion systems are rapid and provide valuable 'short list' data, the information obtained on diffusion rates cannot easily be applied to solid wood. Da Costa's slab technique is obviously advantageous in this respect. Furthermore, it can be so tailored that successive inocula can be sequentially assessed, thereby providing added information on component diffusion as well as total formulation movement. However, care must be taken in interpreting the data since it is not possible to distinguish directly which chemicals in a mult-component formulation have diffused first and hence which are the toxic ones. Similarly, it could be necessary to impose a time restriction on the test with certain types of formulations.
H Greaves

Effect of incising depth and density on treatment of Douglas fir, hem fir and spruce-pine-fir lumber with CCA, ACZA or ACQ
1997 - IRG/WP 97-40093
Incising markedly improves both the depth and uniformity of preservative treatment of refractory wood species, but there are few studies directly comparing the effects of incising depth and density on penetration and retention of commonly used waterborne preservatives in wood species from the western United States. The effects of two incision densities (7300 and 8900 incisions/square meter) at two depths (5 and 7 mm) were investigated using two strength classes of Douglas fir, hem fir and spruce-pine-fir lumber. In general, grade or strength class had no significant effect on treatability. Treatability markedly improved with increasing incision depth, while increased incision density produced less tangible results. Ammonia-based treatments were associated with deeper penetration reflecting the ability of the heat and/or ammonia to improve preservative penetration. Further studies are underway to evaluate the effects of incising and subsequent preservative treatment on strength properties.
M Anderson, J J Morrell, J E Winandy

Long-term protection of stored lumber against mould, stain, and specifically decay: A comparative field test of fungicidal formulations
1984 - IRG/WP 3281
The problem of decay in packaged, unseasoned lumber stored for many months has become of major importance in recent years. Large financial claims have resulted from decay in Canadian lumber stored at length in seaports and storage yards of distributors. For decades acceptable protection from moulds and sapstain was readily achieved with chlorinated phenols applied at appropriate treating levels. However, in recent years, the use of chlorinated phenols in sawmills has become controversial, out of concern for its persistance in the environment and because of its broad spectrum of toxicity to practically all organisms. Although it was realized that this toxicity to humans had been over-emphasized, the discovery of traces of chlorinated dibenzodioxins as a minor impurity of some chlorinated phenols has generated further pressure to abandon the use of the latter. Forintek Canada Corp. has done extensive laboratory and field testing of fungicides for the lumber industry. Most of the field experiments were four-month studies (1) although one dealt with a two year evaluation of preservative retention and protection (2). In June 1981, under contract to Agriculture Canada, we began a field test of five new fungicidal formulations, comparing them with sodium tetra- and pentachlorpheates (NaTCP).
A J Cserjesi, A Byrne, E L Johnson

Bioprocessing preservative-treated waste wood
2000 - IRG/WP 00-50145
Disposal of preservative-treated waste wood is a growing problem worldwide. Bioprocessing the treated wood offers one approach to waste management under certain conditions. One goal is to use wood decay fungi to reduce the volume of waste with an easily managed system in a cost-effective manner. Wood decay fungi were obtained from culture collections in the Mycology Center and Biodeterioration research unit at the USDA-FS Forest Products Laboratory (FPL), Madison, Wisconsin, and from FPL field sites. The 95 isolates had originally been taken from at least 66 sites from around the United States. Isolates were screened in a bioassay (known as the 'choice test') for tolerance to CCA, ACQ, creosote and pentachlorophenol. A tolerant rating was based on fungal growth toward or on treated wood, with 17 tolerant to CCA, 21 to ACQ, 12 to creosote and 5 to pentachlorophenol. Decay capacity of the tolerant isolates was determined as percent weight loss by the ASTM D-1413-76 soil bottle method. We identified 8 isolates for experiments on preservative remediation. Isolates of Meruliporia incrassata and Antrodia radiculosa gave the highest percent degradation of ACQ and CCA-treated wood. Several A. radiculosa isolates and a Neolentinus lepideus isolate grew on creosote-treated wood, but had only a 4-5% weight loss. In this paper we discuss the potential use of decay fungi to degrade or remediate preservative-treated wood.
B Illman, V W Yang, L Ferge

International comparison of three field methods for assessing the in-ground termite resistance of materials - highlights after two years
1999 - IRG/WP 99-20157
First-year results of a comparative study, evaluating the in-ground termite resistance of a range of materials, including CCA and ACQ-treated timbers, using the below-ground exposure, ground contact and graveyard methods against diverse termite faunas were provided in IRG/WP/98-20132. Further annual inspections have confirmed early trends and identified notable differences between sites and methods. Termites have contacted specimens more frequently at tropical sites, irrespective of the method, and in below-ground exposure trials, irrespective of site. Overall, levels of fungal decay have been low. Fungal decay was more prevalent in specimens using the ground-contact and graveyard methods. Notable levels of termite attack have been recorded for some CCA- and ACQ-treated Pinus radiata specimens at the retention of 2kg/m3, after two years or only one year (Phuket, Thailand). Some specimens of the durable timber bald cypress (Taxodium distichum) have sustained significant levels of termite attack and fungal decay.
M Lenz, J W Creffield, A F Preston, B M Kard, C Vongkaluang, Y Sornnuwat

Laboratory evaluation of borate formulations as wood preservatves to control the subterranean termite coptotermes acinaciformis (isoptera: Rhinotermitidae) in Australia
2001 - IRG/WP 01-30266
The termiticidal efficacy of Borocol (sodium octaborate tetrahydrate), boric acid, bore-ester-7 and tri- methyl borate was evaluated in laboratory bioassays against Coptotermes acinaciformis (Froggatt). Seasoned sapwood blocks of Pinus radiata D. Don, and Eucalyptus regnans (F. Muell) were impregnated with the various borate compounds. There were marked differences in mass loss and mortality rate of the termite used in the bioassay units for different boron retentions. After 8 weeks the result suggested that, borate was toxic to termites in laboratory bioassay even at 0.20% m/m BAE and caused significant termite mortality. However, termites were not deterred from attacking the borate treated timber at higher retentions of > 2.0% m/m BAE. These laboratory results indicated that the minimum borate treatment required to protect timber against termites attack and damage was > 1.0% m/m BAE.
B M Ahmed, J R J French, P Vinden

Copper leaching from Kemwood ACQ and Embalit CBC treated wood products
2000 - IRG/WP 00-50150
TNO has performed a study on the leaching of copper from Kemwood ACQ and Embalit CBC treated wood products, further referred to as ACQ and CBC. The sawn dry wood has been impregnated using an industrial vacuum-pressure process with ACQ (with or without Ultrawood 4) or with CBC, under supervision of Flexchemie B.V. After treatment samples have been transported and subjected to leaching tests at TNO. The leaching tests applied were a submersion test according to NEN 7345 and shower tests according to a fixed protocol (Havermans et al., 1993). Parallel to each shower tests two or three screening tests for leaching have been performed, according to the existing guideline (BRL 0601, 1999) and according to experimental spray and submersion protocols. The screening should indicate, if the leaching limits of the guideline are likely to be met or not. The results of the screening leaching test have been plotted against the results of the shower tests. It has shown that the existing leaching limit for the "standard" guideline screening test of 0.5 mg copper per ml. is too low and does not indicate if the wood will perform well in the shower test, for both ACQ and CBC treated wood. The experimental spray test has shown to be fairly good as prediction for compliance in the shower test. Furthermore the submersion test according to NEN 7345 has shown promising reductions with a factor 3,7 of copper leaching in ACQ and Ultrawood 4 treated Norway spruce compared to an earlier test with ACQ treated Scots pine. The copper emission in CBC treated Scots pine was a factor 2,5 higher compared to the ACQ-Ultrawood 4 treated Norway spruce.
P Esser, W L D Suitela, H Trompetter

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