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Weathering of copper-amine treated wood
2000 - IRG/WP 00-40155
Copper ethanolamine (Cu-EA) treated southern pine (SP) were artificially weathered with a QUV Weathering Tester. The weathering regime was composed of a continuous UV-light irradiation for 2 hours followed by a water spray for 18 minutes for a total time of 1200 hours. The changes on the surface of the weathered samples were characterized by Fourier transform infrared spectroscopy (FTIR) analysis, color and contact angle measurements. FTIR indicates that Cu-EA treatment can retard the surface degradation during weathering. The reduction of the peak intensity at 1510 cm-1, characteristic of the wood lignin was less pronounced for Cu-Ea treated wood than for untreated or ethanolamine treated wood. This reduction in 1510 cm-1 intensity decreases with the increase of copper EA retention in treated wood. The color change expressed by the value of DE indicated that untreated and Cu-EA treated wood change color rapidly during the first 200 hours irradiation and the color change remained relatively constant thereafter. The values of DE for untreated and ethanolamine treated sample were higher than the values of Cu-Ea treated. Changes in the lightness of wood samples were also observed with the duration of irradiation. The lightness of untreated and Cu-MEA treated samples decreased during the first 100-hour weathering. These samples regained their lightness after 100 hours irradiation. For samples treated with copper concentration above 0.25%, the change in lightness was rather small. The contact angle measurement indicates that the wettability of wood surface increases with the duration of QUV exposure. Untreated and MEA treated wood samples changed contact angles rapidly, and The contact angle of untreated and ethanol amine treated samples dropped from about 75"5 degree to zero after 600 hours artificial weathering. Treatment with Cu-MEA can slow the decreasing in contact angle. After 1200 hours, the contact angle of Cu-EA treated wood dropped from 100 to a minimum between 25 and 60 degree. As the copper concentration increases, the rate of changing contact angle decreases. This study suggests that a copper amine treatment increases the hydrophobic and the resitance to photodegradation.
J Zhang, D P Kamdem


Microwave treatment to Accelerated fixation of copper-ethanolamine (Cu-EA) treated wood
2004 - IRG/WP 04-40271
This study evaluated the use of microwave post-treatment to accelerate fixation of copper-ethanolamine (Cu-EA) treated 19 mm southern yellow pine sapwood cubes. Cubes were pressure treated at 3.2 and 6.4 kg/m3 Cu retention target, after which they were microwave post treated during different duration periods. An accelerated AWPA leaching test was conducted during 300 hours to determine the amount of copper leached after the microwave treatment. The amount of copper leached was reduced 40 % after 5-min microwave treatment. The moisture content and the temperature of the cubes were monitored during the microwave treatment. This study clearly demonstrated that post-microwave treatment could be used effectively to reduce the amount of copper leached after 300 hours accelerated leaching test. Further work is needed to determine the effect of the sample size, the power and duration of the microwave treatment on copper leachability.
Jinzhen Cao, D P Kamdem


Microdistribution of Copper in Copper-Ethanolamine (Cu-EA) Treated Southern Yellow Pine (Pinus spp.) related to density distribution
2004 - IRG/WP 04-40270
The relationship between copper absorption and density distribution in wood cell walls was investigated in this study. The density distribution on layer level was obtained from two approaches: (1) calculation by using data obtained from literature; (2) microdistribution of carbon and oxygen atoms in the wood cell. The microdistribution of carbon and oxygen in untreated southern yellow pine (Pinus spp.) sapwood, as well as copper in cell walls of copper-ethanolamine (Cu-EA) treated wood was determined by scanning electron microscopy coupled with energy dispersive X-Ray analysis (SEM-EDXA). Both approaches for density distribution led to the same result: the density was higher in the compound middle lamella (ML) and cell corners (CC) than in the secondary wall. The concentration / intensity of Cu, C and O in the cell wall follow the same trend as the density distribution; suggesting that density may play a major role in SEM-EDXA study of the distribution of metal-containing wood preservatives within the wood cell wall.
Jinzhen Cao, D P Kamdem, E Pasek


FTIR characterization of copper ethanolamine - wood interaction
1999 - IRG/WP 99-20154
The interaction of copper ethanolamine (Cu-EA) and wood components was studied by using Fourier transform infrared spectroscopy (FTIR). In Cu-EA treated wood, significant reduction was noticed on the band attributed to carbonyl vibration from carboxylic groups at 1735±5 cm-1 and an increase in band intensity was obtained from carbonyl in carboxylate at 1595±5 cm-1. The same observation was made in Cu-EA treated holocellulose. Cu-EA treated lignin resulted in a reduction in the aromatic ester band at 1710±5 cm-1 and an increase in carbonyl from carboxylate at 1595±5 cm-1. Bands at 1370 cm-1 and 1221 cm-1 assigned to phenolic hydroxyl groups, exhibited a decrease in intensity after the treatment. From these data, it is concluded that Cu-EA interact with carboxylic groups, phenolic hydroxyl groups and ester groups from lignin to form copper carboxylate and phenolate complexes.
Jun Zhang, D P Kamdem


Comparison of Different Methods for Assessing the Performance of Preservatives in the BAM Fungus Cellar Test
1998 - IRG/WP 98-20149
The fungus cellar test is a common means to get reliable data on the long term performance of treated wood in soil contact. A constantly high humidity and a suitable of water holding capacity for a range of micro-organisms provide high decay rates in untreated wood and produce intensive microbial pressures on wood treated with biocides. Presently a range of biocides are under test in the BAM fungus cellar and the results will be presented for the following types of biocides: Tebuconazole in combination with copper and boron (5 years fungus cellar), quats with copper and boron (5 years fungus cellar) and Cu-organic compound combined with copper and boron (3 years fungus cellar). Figures will be shown on the development of the Modulus of Elasticity (MOE) over the years and on an assessment of the stakes according to EN 252.
I Stephan, M Grinda, D Rudolph


Collaborative soft rot tests: PRL tests of Cu/Cr/As preservative using method of Document No: IRG/WP/208
1973 - IRG/WP 223
These tests were undertaken as a preliminary to the next series of collaborative soft rot tests. An interim report has already been presented at Berlin in 1972 as Document No: IRG/WP/211
J K Carey, J G Savory


Cu, Cr and As distribution in soils adjacent to CCA treated utility poles in Eastern Black Sea Region of Turkey
2004 - IRG/WP 04-50214
In this study, the main objective was to asses the distribution of Cu, Cr, and As in soils adjacent to CCA treated utility poles in Eastern Blacksea Region of Turkey (Trabzon, Rize and Artvin ) and determine the influence of soil composition. Surface (0-5cm), subsurface soil samples (30-40cm) were collected near CCA-treated utility poles and control soil samples away from CCA-treated utility poles were also collected. Water holding capacity, pH, mechanical properties of soil samples were determined for both depth levels. Results showed that Cu, Cr and As concentration in soil samples taken from all three cities in 0-5cm depth was higher than soil samples taken from 30-40cm depth. Cu, Cr and As concentrations were much higher in soil samples taken from city of Rize.
E D Gezer, Ü C Yildiz, A Temiz, S Yildiz, E Dizman


Evaluation of wood treated with copper-based preservatives for Cu loss during exposure to heat and copper-tolerant Bacillus licheniformis
1999 - IRG/WP 99-20155
Copper-based wood preservatives need to be effective against exposure to all types of microorganisms. Wood treated with six copper-based preservatives was exposed to 121°C and 20 psi pressure for 15 minutes under standard autoclave conditions and the copper-tolerant bacterium, Bacillus licheniformis CC01, for 10 d at 28°C and 150 rpm. Sixteen to 37 percent of the copper was released from the wood during autoclaving, with copper citrate demonstrating the highest percent loss. Forty-four to 82 percent of the copper remaining in the samples following autoclaving was removed during exposure to the bacterium in liquid culture; copper naphthenate in oil and ACQ-D had losses of eighty percent or greater of the remaining copper. The bacterium removed as much or more total copper in 4 of 6 gas-sterilized samples (85-94%) than the cumulative effects of steam-sterilization and the bacterium on treated samples. Copper loss from in-service treated wood compromises the efficacy of copper-based wood preservatives.
D M Crawford, C A Clausen


Collaborative soft rot tests: Interim report on PRL tests of Cu/Cr/As preservative using method of Document No: IRG/WP/208
1972 - IRG/WP 211
Preservative: Tanalith CT.106 - Results obtained with beech are given in the table and indicate a toxic limit of 16.7-19.2 kg/m³ - The initial soil moisture content was adjusted to 27.8% (the water holding capacity). Noticeable drying out has occurred in some of the test bottles.
J G Savory


Migration of active ingredients from treated timber into fresh water
1991 - IRG/WP 3669
Spruce roundwoods and segments were treated with three different wood preservatives. Two of them containing copper and chromium the other one free of chromium. After fixation (3 weeks, 20°C) the specimens were leached by using artifical rain or by shaking the segments for one hour in contact with demineralized water. The water was analysed for the relevant elements of the preservative tested. Leachability of the components from the copper-chromate treated wood decreases. After 4-8 leaching cycles an almost constant migration of wood-preservatives, depending on the leaching method and the pH-value of water applied, was determined for the chromate containing preservatives. In the course of leaching cycles a constant rate of migrated copper from the preservative free of chromium was determined after 4 - about 17 leaching cycles. After 16 leachings of the segments the leached copper as calculated on the copper retention was determined to 1.6 - 5% for the chromium containing preservatives and about 22% for the tested variation of the new type of preservative.
H Klipp, H Willeitner, K Brandt, A Müller-Grimm


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


An appraisal of methods for environmental testing of leachates from salt-treated wood (2)
1998 - IRG/WP 98-50110
For wood preservatives for use in hazard class 4 information on the ecotoxicity of preservatives and ingredients as well as on the effect of losses from impregnated timber is needed for a proper environmental risk assessment. In the evaluation of a suitable test procedure the leaching behaviour of copper-based formulations was studied using analytical and ecotoxicological test methodology. These studies included an analytical comparison of end grain sealed and not sealed wood blocks. Using sensitive bioindicators in ecotoxicological studies, real effects of the leachates gained from EN 84 were measured. The possibility to use a laboratory test procedure based on the leaching according to EN 84 is shown and discussed for the risk assessment of treated timber.
H W Wegen, A Platen, G M F Van Eetvelde, M Stevens


EPR investigations of interactions between ammoniacal Cu(II) octanoate and wood
1996 - IRG/WP 96-30110
Ammoniacal solutions of copper(II) octanoate [ C u . h l f . 2 . r h l f.(O2CC7H15)4], interactions of these solutions with wood and wood components, and leaching of copper(II) octanoate from impregnated wood samples, have been studied by electron paramagnetic resonance (EPR) method. It is still not clear if in the Cu(II) octanoate - water - ammonia system, Cu(II) remains in a (copper(II) octanoate - ammonia) complex. The majority of leached Cu(II) with distilled water and a solution simulating acid precipitations was washed out in the first five hours of leaching procedure (up to 35% of initial Cu(II)). Time dependence studies of interactions of ammoniacal Cu(II) octanoate with wood, cellulose and brown rotted lignin showed, that the fastest and most significant was the reaction with lignin. Cu(II) is immobilised also on cellulose. A significant contribution of ammonia evaporation to the fixation mechanism of the preservative was observed as well.
F Dagarin, M Petric, F Pohleven, M Sentjurc


The course of fixation of Cu-Cr-As wood preservatives
1972 - IRG/WP 307
Copper-chrome-arsenic (CCA) preservatives in contact with wood result in an instant extensive increase of pH, because of ion-exchange and adsorption reactions with the wood. During precipitation of the active elements the pH continuously increases but reaches a maximum, when all chrome is consumed. Some of the early reaction products are unstable and slowly convert via dissolution into stable compounds. The conversion proceeds by proton liberating as well as proton consuming reactions. The pH therefore alternatively decreases and increases until the reactions cease after several months. The final equilibrium fixation products are: ion-exchange fixation of Cu to the wood CrAsO4, Cu(OH)CuAsO4 and Cr(OH)3. The chrome fixation is 2nd order with respect to hexavalent chrome in the liquid phase, four regions with distinct chrome fixation rate constants were found. A hypothesis is given for the mechanism of fixation.
S-E Dahlgren


Health hazards and environmental aspects when using Cu-HDO-containing wood preservatives in vacuum pressure plants
1993 - IRG/WP 93-50001-11
Apart from the biological efficacy of wood preservatives, the health and environmental aspects concerning the utilisation of wood preservatives, the use of treated timber and the disposal of impregnated wood are of high significance today. Therefore, information on a possible aerial concentration of wood preservatives, on the mobility of active substances in soil leached from treated timber in service and on the composition and toxicity of thermal decomposition gases releasing on combustion of impregnated wood, are of absolutely fundamental interest. Measuring procedures relevant for the practical application will be presented, and the results concerning the utilisation of Cu-HDO-containing wood preservatives will be described. With the proper use of Cu-HDO-containing wood preservatives, the aerial concentration at workplace falls distinctly below the maximum permissible limit. If vacuum pressure treated timber is used properly, no active substances will seep into the ground water as a result of the leaching process of impregnated wood in service. The composition measured and the acute toxicity of the thermal decomposition gases released on combustion of impregnated wood may axtually be compared to those of untreated timber.
W Hettler, S Breyne, M Maier


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


The effect of wood preservatives on the relation between the electric resistance and moisture content in scots pine (Pinus sylvestris L.) sapwood
1998 - IRG/WP 98-20142
The effect of two types wood preservatives (TBTO and CuHDO) on moisture content measurements with an electric resistance meter in pine sapwood is assessed. High and low concentration impregnated pine sapwood is climatized at different relative humidities. Once climatized the samples are weighed and the moisture content is measured with an electric resistance meter by fixed stainless steel, isolated measuring pins. Subsequently the wood is dried for 48 hours at 103°C and weighed to gain the correct climatized moisture content. The reading values of electrical moisture content measurements are compared to the actual moisture content. Compared to the original correction lines for pine, an increase in concentration of metal ions leads to a steeper slope, i.e. the conductivity of the treated wood increases. The change in conductivity is so small that electrical resistance measurements are still practicable. However, for precise measurements new correction lines, which depend on concentration and type of preservative, need to be established.
B W Holleboom, W J Homan


Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 5: Effect of wood species and preservative composition on the leaching during storage
1975 - IRG/WP 354
Conversion reactions during storage of CCA treated wood take place even at and below the fiber saturation point as long as ion transport is possible. Increase in drying temperature increases the final pH of the treated wood and the leachability of Cu and decreases slightly the leachability of Cr, while the leachability of As is not affected. This temperature effect is considered to be of no technical importance, but may be of importance when preparing material for biological testing. The length of the wet fixation period before the drying does not influence the results. The presence of alkali sulfates in some preservatives affects the pH of the unleached wood but not the leachability of the active elements. The natural pH of the wood determines to a considerable extent the final pH and the leachability. A correlation was established between the leachability of Cu and As versus the final pH in wood. When treated with 2-2.5% preservative solutions some wood species: Douglas fir, Ponderosa pine and to a lesser degree Southern yellow pine, showed unexpectedly high As leachability, while on doubling the concentration normal leachability data were obtained. The study included three commercial CCA preservatives: Boliden K33, Celcure AP and Tanalith C, and one experimental variety of Celcure AP without sodium sulfate.
S-E Dahlgren


Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 6: The length of the primary precipitation period
1975 - IRG/WP 359
The end of the primary precipitation fixation period of CCA preservatives coincides with the first peak in pH versus time. This offers a simple way of estimating the duration of the period. The duration is determined by a number of factors and their interactions, the most important of which are: wood species (anatomy, natural pH, accessibility of reducing agents), preservative type, preservative concentration and temperature. For interpretation of experimental data the effect of these factors is discussed in the light of the chemistry and the mechanism of fixation of CCA preservatives. For a proper handling of the treated timber, knowledge of the duration in actual working conditions is essential.
S-E Dahlgren


The fate of salt preservatives in facility yard soils and decontamination of soils and drainage waters
1993 - IRG/WP 93-50001-25
Extensive studies during the past 10 to 15 years revealed that noticeable amounts of preservative components may be released in the environment by dripping off or by rain prior to fixation unless adequate precautions are taken. Therefore, soil and groundwater contamination especially from chromium-VI compounds but also from other inorganic and organic constituents exist in impregnation plants, possibly endangering the soil and groundwater ecosystem. The actual risk potential originating from chromium-containing wood preservatives in a practical situation are to be studied in the frame of a comprehensive research programme sponsored by the German Ministry of Research and Technology (BMFT). Accompanying laboratory investigations are performed with the aim of assessing the various types of water-soluble wood preservatives with respect to whether or possibly which compounds remain mobile und thus bio-available in the soil. Special attention is drawn to the question as to which effective constituents are adsorbed to soil particles depending on the mineralogical-geological composition of the soil, and at what situation the retention capacity for effective components of different soils would be exceeded. The results of the pilot study and of parallel running laboratory tests serve as a basis of deterioration analyses for grading and assessing the endangering potential in the ecosystem and shall provide a basis for the choice of adequate remedial concepts and measures to avoid such environmental impacts.
R-D Peek, H Klipp, K Brandt


Electrochemical removal of Cu, Cr and As from CCA-treated waste wood
2001 - IRG/WP 01-50166-18
CCA-treated waste wood poses a potential environmental problem due to the content of copper, chromium and arsenic. This paper presents the results obtained by electrodialytic remediation of CCA-treated waste wood. It is found that more than 90% Cu, and approximately 85% Cr and As was removed from the wood during the remediation. Thereby the concentration of copper in the wood is reduced from app. 426 ppm to app. 25 ppm, chromium is reduced from app. 837 ppm to app.135 ppm and the arsenic content decreases from app. 589 ppm to app. 151 ppm. After remediation the removed metals are collected into liquids. The use of ion exchange membranes to separate the wood from the electrolytes result in a distribution of the metals after remediation that makes the collection of the metals easier, and reuse of the metals, for e.g. new CCA, may be possible.
I V Kristensen, L M Ottosen, A B Ribeiro, A Villumsen


Susceptibility of antisapstain fungicides to rain wash-off
1994 - IRG/WP 94-30046
Results of trials using miniature timber packets and simulated rain wash-off are described. Six fungicidal actives in five commercial antisapstain formulations were involved, and a clear influence of rainfall timing after antisapstain treatment was demonstrated. Differences between actives and formulations were most marked where water-spray was applied in the first hour after treatment, though even when applied after a 48 hour delay there were up to ten-fold differences in the percentages mobilised. Possible mechanisms of fixation are discussed in relation to known formulation properties. Results from a full scale trial at a sawmill are also given, and comparison made with the small-scale packet experiments. It is concluded that the results were very similar. The work is extrapolated to the 'real-life' sawmill situation, and conclusions drawn as to the likely results of heavy rain exposure at different times after fungicidal treatment of timber.
R N Wakeling, D J Cross, D R Eden, P N Maynard


Environmental fate of copper-based wood preservatives in different soil substrates - Part 1: Screening of the metal adsorption potential
1998 - IRG/WP 98-50101-21 a
In treatment plants, spillage of wood preservatives onto soil may be of environmental concern. This potential soil contamination served as an objective for a screening study. Three different mineral soils, a mineral substrate and two horticultural substrates are examined for their sorptive potential of copper through mixing with wood preservative solutions. Depending on the soil/substrate characteristics and the chemical nature of the preservatives used, copper is adsorbed to a higher extent with increasing concentration of the test solution. Soils with low organic matter and clay content show an upper limit of adsorption, irrespective of the product tested. The other soil types clearly exhibit a levelling-out effect from 2 to 4 hours on, often correlating with the initial metal concentration of the product though dependent on the chemical nature and buffering capacity of the active ingredients.
G M F Van Eetvelde, J M Mwangi, F Tack, R Hartmann, M Stevens


Microwave digestion of preserved wood for the determination of Cu, Cr, As, B and P in quality control
1991 - IRG/WP 2364
A microwave digestion method for the determination of copper, chromium, arsenic, boron and phosphorus in preserved woods is described. Samples were digested with nitric acid in pressure-relief type teflon PFA vessels by microwave heating in a commercial laboratory microwave oven. Fast, efficient and complete digestion was achieved within 29 min for 12 samples. The digestion time compared favourably with the 2 h required for conventional procedures. Furthermore the consumption of reagents was reduced significantly. The resulting solutions were analysed by inductively coupled plasma atomic emission spectrometry, but the solutions are also suitable for atomic absorption spectrometry.
N Bernth, L B Sheard


Formation of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) during the combustion of impregnated wood
1995 - IRG/WP 95-50040-19
Wood waste and industrial wood residues often contain various preservatives. The waste management for these residuals can be recycling, deposition or combustion. Among the three possibilities, combustion seems to be the most efficient way of disposal. To obtain detailed information about emissions of organic compounds with environmental impact, especially polychlorinated dibenzo-p-dioxins (PCDD) and furans (PCDF), different impregnated wood materials were incinerated in two furnaces after mixing with non-treated wood in a ratio of 1:4. The combustion process of residues containing organic or inorganic preservatives is influenced by the elementary composition of the preservative and the thermal and oxidative reaction paths in the flame. It was found that the concentrations of PCDD and PCDF in the exhaust gas can be kept low under good combustion conditions. However, a non-regular incineration process strongly supports increased emissions of PCDD and PCDF.
T Salthammer, H Klipp, R-D Peek


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