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Performance of treated fence posts after 6 years in five test plots in the State of Sao Paulo - Brazil
1976 - IRG/WP 376
Fence posts treated with creosote, pentachlorophenol and creosote/ pentachlorophenol mixtures showed good performance after 6 years of exposure in five test plots located in the State of Sao Paulo - Brazil. Good results were also achieved with copper sulphate/sodium arsenate and copper sulphate/potassium dichromate mixtures. Fungi and termites were the main destroying agents found attacking the posts.
M S Cavalcante


The leaching of copper, chrome and arsenate from CCA-impregnated poles stored for ten years in running water
1978 - IRG/WP 3122
There is no evidence to indicate that the chromium and copper components are leached from the outermost 5 mm of sapwood in poles impregnated with Boliden K33 and Tanalith C and stored in running water for ten years. The arsenic component, however, seems to be leached out during the first few months to an extent of about 20% of the initial amount. The leaching time is dependent on the preservative used.
F G Evans


An introduction to environmental aspects of groundwater arsenic and CCA treated wood poles in Bangladesh
1997 - IRG/WP 97-50081
The environment comprises biosphere, lithosphere, atmosphere and hydrosphere. Therefore, environmental science is a multi-disciplinary study, includes life sciences, physical sciences, chemical sciences, geology, geography, meteorology, forestry, agriculture, soil science, hydrology, ecology, public health, engineering etc. Tremendous industrial and mining activities, deforestation and population explosion are threatening the very existence of life on earth.Groundwater is used for irrigation, drinking and other domestic purposes where other sources of water are not plenty. Groundwater contain different metals resulting from soluble minerals, deposited in ground during its origin. Thus concentration of metals in surface soils and water are increased day by day by lifting of groundwater. Surface soils and water also receive metals from industries and mines and as a result of multipurpose use of products from those. Deforestation is controlled by plantation and preservation of forest products by different wood preservatives. Recently groundwater in some underground rocks of Tertiary and Quarternary age in Bangladesh is very often known to contain arsenic (As) above permissible limits . On the other hand chromated copper arsenate (CCA) impregnated wooden poles has been used for rural electrification in Bangladesh since 1979. It is an attempt to find out through research and review of literatures that whether the groundwater As is contaminatable from As used in wood poles and whether the components of CCA cause environmental problems. Possible way of purification of arsenic containing groundwater for drinking have been suggested.
A K Lahiry


Performance of chromated copper arsenate-treated aspen fence posts installed in Forintek's Eastern test plot from 1951 to 1963
1984 - IRG/WP 3272
Aspen poplar fence posts were pressure treated by the full cell process using three formulations of copper chrome arsenate wood preservative. A total of one hundred and fifty nine of the posts were installed in service in Forintek's Chalk River post plot from 1951 to 1962. During the 1982 general inspection of the post plot all 159 posts were still in service. A groundline inspection was carried out on the material to determine the extent to which decay had progressed during this period. Samples were taken from the surface of tanalith C treated posts and subsequent microscopic examination revealed that soft rot attack was present in the outer portion of posts. The groundline area of posts treated with (K 33), CCA type B and (greensalt) CCA type A were in generally good condition after 22 years and 31 years respectively. Rate of decay was highest for CCA-C tanalith treated posts at 0.3 mm per year with a retention of 3.04 kg/m³ oxides.
C D Ralph


A laboratory soil-block decay evaluation of plywoods edge-treated with preservatives
1982 - IRG/WP 2174
Preservative-treated plywood used under conditions or severe decay hazard frequently has its original, or cut edges, protected by the application of a field-cut preservative. This study uses a laboratory test method to compare the efficacy of four commercial preservative treatments against two commonly occurring brown-rot fungi. The results are not meant to indicate the service life of such treated plywood.
R S Smith, A Byrne


Migration of Metals from Douglas-fir Lumber Treated with ACZA or Pentachlorophenol Using Best Management Practices: Preliminary Tests
2005 - IRG/WP 05-50224-4
The potential for migration of preservative components from ammoniacal copper zinc arsenate (ACZA) and pentachlorophenol treated Douglas-fir lumber in non-soil contact exposure was assessed in a simulated rainfall device. Metal levels from ACZA treated wood were elevated for the first 30 minutes of rainfall and then declined sharply. Repeated cycles of rainfall led to declines in initial metal losses suggesting that surface metals were gradually depleted from the wood. Penta losses were also initially high, but then declined at rates related to rainfall level. The results suggest that preservative losses from treated wood in above ground exposures can be predicted.
J J Morrell, Hua Chen, J Simonsen


Treatability of Siberian larch and spruce with chromated copper arsenate
1996 - IRG/WP 96-40060
Heartwood of Siberian larch (Larix gmelini) and spruce (Picea jezoensis) was pressure treated with chromated copper arsenate (CCA) Type B using a full cell process. Larch heartwood was somewhat difficult to treat than the spruce, although both species did not meet a minimum requirements of penetration and retention specified by the American Wood Preservers' Association (AWPA) for difficult to treat wood species in ground contact. To improve the preservative treatability of refractory larch and spruce, end matched heartwood lumber had been incised using either a conventional or a double density incising pattern, and then pressure treated with CCA Type B. The use of double density incising is necessary for spruce heartwood in order to acheive adequate treatment with CCA; however, the increase in incision densities and/or the use of high treating pressure may be required for adequate treatment of larch heartwood.
Gyu-Hyeok Kim, Woo-Gue Jee, Jae-Jin Kim


A Soil Bed Test of the Effect of CCA Penetration on the Performance of Hem-fir Plywood
2004 - IRG/WP 04-30332
An accelerated decay test was set up to compare the performance of CCA-treated Western hemlock/amabilis fir plywood treated to meet the preserved wood foundation (PWF) retention standard with various patterns of preservative penetration. Short lengths of treated plywood and comparable untreated material were installed in a soil bed. After eleven years of exposure, the CCA treatments were all sound regardless of penetration, while the untreated material had failed due to decay within three years.
P I Morris, J K Ingram


Fixation of chromated copper arsenate (CCA) wood preservative in Australian hardwoods: A comparison of three Eucalyptus species
1996 - IRG/WP 96-30107
New environmental guidelines for the management of CCA treatment plants were released in Australia in 1995. This has stimulated interest in techniques for controlling or accelerating the fixation of CCA in freshly treated timber products. The ability to understand, then effectively control and/or accelerate fixation of CCA in treated timber products can be an economic, technical and environmental advantage. Data available on fixation of CCA in timber commodities however, is mainly on softwood not hardwood species. In this paper, the rate of fixation of CCA Type C Oxide in poles of three species of Australian Eucalyptus was monitored over a six week period following treatment. These results will assist in the design of adequate drip pad and undercover storage area for pole treaters in South East Queensland.
J Holmes


Effect of treatment process on performance of copper-chrome-arsenate. Part 2: Field stake tests
1995 - IRG/WP 95-40046
Pinus radiata sapwood stakes 20 x 20 x 400 mm³ were treated with CCA Type C using a range of concentrations and three treatment processes; Bethell, Lowry and Rueping. Preservative retention was determined by chemical analysis of treated material. Following fixation stakes were installed in a randomised plot in the Whaka graveyard located on the FRI campus. Stakes were inspected at yearly intervals using AWPA M-10 standard procedure. After 5 years' exposure performance was strongly correlated with preservative retention expressed either as copper retention or total element (Cu+Cr+As) retention. Treatment process had very little effect on performance and confirmed results obtained from similar material exposed in fungus cellar tests. Implications of these results for commercial treatment operations are discussed.
M E Hedley, J Anderson, J B Foster, B E Patterson


Preliminary studies on cellulase production by selected Basidiomycetes and the effect of copper-chrome-arsenate on these enzymes
1980 - IRG/WP 1122
The growth of wood-destroying fungi on ligno-cellulosic materials depends on the production of many enzymes, of which probably the most important is the multi component cellulase system. Within this system, at least three different kinds of enzym are believed to be involved in crystalline cellulose decomposition. These are endo-1,4-glucanase, exo-1,4-ß glucanase and ß-glucosidase. Most of the recent research on cellulases has concerned isolation, purification and characterisation of the enzymes and their application in the utilisation of cellulosic waste. Information on the chemical inhibition of cellulases is available but there is little reference to the interaction of wood-attacking cellulases and the preservatives which are used to protect wood. The objective of this work is to study the production and activity of cellulases of selected basidiomycetes and to observe the effect of wood-preservatives on these enzymes. Preliminary studies with copper-chrome-arsenate (CCA) are reported here
O Collett


Wood Preservatives Science Issues: US EPA’s Perspective
2005 - IRG/WP 05-50224-2
The USEPA Office of Pesticide Programs (OPP), Antimicrobials Division (AD), regulates the use of chemicals registered as wood preservatives in the United States. An overview of the registration and re-registration process is presented. The wood preservatives data requirements include toxicological, human exposure, ecological, and environmental fate data. A detailed discussion of wood preservatives data requirements is presented. Currently, the three heavy duty wood preservatives (Pentachlorophenol, Chromated Copper Arsenate, and Creosote) are undergoing the re-registration process. This process is mandated by Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The re-registration process ensures that older pesticides meet contemporary safety standards and data requirements. The challenges of regulating the treated wood will be discussed.
N Elkassabany


Effectiveness of copper/chromium salts as wood preservatives against Limnoria tripunctata Menzies in laboratory tests
1977 - IRG/WP 431
During the last joint meeting of IRG and COIPM a co-operative programme of tests with copper/chromium salts as wood preservatives against marine borers was discussed and agreed. In this connection the results of a laboratory test in the BAM with Limnoria tripunctata Menzies will be of interest. But as the respective paper is written in German (H. Kühne; G. Becker: Laboratoriumsversuche über die Wirkung kupferhaltiger Schutzsalzgemische auf die Holzbohrassel Limnoria tripunctata Menzies) (Material u. Organismen 5 (1970) No 4, 307-319) a comprehensive summary is given in English for IRG-COIPM members.
H Kühne


Safe application of copper-chrome-arsenate preservatives
1975 - IRG/WP 377
All wood preservatives contain biologically active substances and must, by design, be in some measure toxic to man. There is nothing fundamentally difficult, however, about using a wood preservative with complete safety. It depends on knowing the risks to health and/or the environment, which the preservative may present, and planning application accordingly. In this paper we examine these and other factors for copper-chrome-arsenate (CCA) preservatives applied in vacuum/pressure plants. We review briefly the toxicological properties of the components and their joint action; the contribution which design and the operation of plant make to safe treatment; also the training of plant operators, to ensure that the potential risks in applying CCAs are fully understood. We shall consider the functions of product labelling; to advisc others - concerned with transport - of the nature of preservatives, especially concentrates. The importance is emphasised of being able, by prior planning, to act swiftly and effectively to deal with any unforeseen emergencies, however infrequent these may be. This paper is not concerned with any risks to man and other animals arising from use of CCA-treated wood. After treatment, fixation leaves the preservative components less readily available as contaminants of the environment.
I N Stalker, P B Cornwell


Effects of surfactants and ultrasonic energy on the treatment of wood with chromated copper arsenate
1977 - IRG/WP 3108
Sugar pine stakes 1'' x 1" x 16" were treated by a hot-water bath followed by soaking in cold CCA solution for 10 to 30 minutes. A similar number of stakes were treated by a cold-cold bath. Half of the stakes were subjected to ultrasonic energy during the CCA bath. The mean absorption for stakes given the hot-cold bath was 18.52 pcf (297 kg/m³) and 4.64 pcf (74 kg/m³) for those given the cold-cold bath. The rates of absorption were o.323 pcf (5 kg/m³) per minute and 0.053 pcf (0.85 kg/m³) per minute, respectively. The relationship between absorption in pounds per cubic foot (Y) and soaking time in minutes (X); Y = 12.27+0.323 X, was linear and significant. The linear relationship for the cold-cold treatment was poor (r = 0.305). Neither ultrasonic energy, nor its interaction with soaking time, had a significant effect on solution absorption for either the hot-cold or cold-cold treatments. In a second series, the stakes were treated in the CCA solution with a 3-minute dip, a 48-hour cold soak, and Lowry pressure. Half of the stakes were treated in the solution to which a surfactant had been added. The interacting effect of surfactant and method of treatment was significant. The highest absorption was obtained when the specimens were treated with the solution containing the surfactant by the Lowry method, 35.13 pcf (563 kg/m³). In comparison, the absorption was 22.55 pcf (361 kg/m³), 36 percent lower, when surfactant was not used. The surfactant had a beneficial effect on the results of the 3-minute dip, but not the 48-hour soak.
C S Walters


Relative performance of copper/chrome/boron (CCB) and copper/chrome/arsenate (CCA) in ground contact
1992 - IRG/WP 92-3694
The performance of four retentions each of an oxide CCA formulation and a salt formulation of CCB in radiata pine and European beech was compared after 18 years' field exposure. In radiata pine CCA oxide was more effective (4 failures out of 40) than CCB (9 failures out of 40). However, in European beech CCB was substantially more effective (22 failures) than CCA oxide (all failed). Analysis of failed stakes showed that up to 85% of arsenic had been lost from below ground portions of CCA oxide-treated beech stakes compared with 75% of boron from CCB-treated beech stakes. Percentage losses of copper and chromium were less.
M E Hedley


Equilibrium distribution of toxic elements in the burning of impregnated wood
2001 - IRG/WP 01-50172
The current work focuses on predicting the behavior of arsenic, chromium, and copper in the burning of impregnated wood. A theoretical method is used to study the chemistry of the system, with special interest directed towards the vaporization tendency of the potentially toxic elements. The core of the study is the global equilibrium analysis that simultaneously takes into consideration all chemical reactions. The results of the present study indicate that chromium and copper are unlikely to volatilize at combustion temperatures. Arsenic appears to be more volatile. Nevertheless, the prediction showed that it may be captured by calcium of the wood ash, and small amounts are likely to dissolve in the slag-phase of the ash. It may also form non-volatile compounds with magnesium, copper, and chromium and other elements of the impregnated wood, which efficiently hinders its emissions as gaseous species.
K Sandelin, R Backman


Soft-rot control in hardwoods treated with chromated copper arsenate preservatives. Part 3: Influence of wood substrate and copper loadings
1977 - IRG/WP 2100
The hypothesis is proposed that hardwoods need more chromated copper arsenate (CCA) than softwoods to protect them from soft-rot attack mainly because hardwoods are more readily consumed by soft-rot fungi. Simple model systems, using copper-supplemented agar or groundwood pulp treated with CCA showed that fungi tolerated more toxicant (copper) as more available substrate (malt) was provided. Soft-rot tests with CCA-treated hardwood blocks provided typical dosage-response curves when results were expressed as a ratio of substrate to toxicant (wood to copper). Furthermore, hardwoods needed 10 to 20 times more copper as CCA than softwoods to prevent soft-rot attack. When CCA was substituted by ammoniacal copper arsenate in 5 hardwoods, similar threshold values for soft-rot attack were obtained in terms of a wood-to-copper ratio. Hence, CCA may be behaving poorly against soft-rot fungi in our hardwood specimens mainly because the substrate contained too little copper. The practical implications of these results are discussed.
M A Hulme, J A Butcher


A survey of the incidence of decay in copper-chrome-arsenate treated trellis support posts used in horticulture in New Zealand
1984 - IRG/WP 1225
Copper-chrom-arsenate treated softwood posts used as trellis support structures in 5 major horticultural districts of New Zealand were systematically examined for presence of decay. Principal crops on properties examined were grapes and kiwifruit; a minority of properties grew hops, boysenberries, and dwarf apples. Occurrence and severity of decay were variable within specific age classes of posts on individual properties and also between properties in the same region which had posts of similar age. Incidence of decay was higher in posts set in soils which were highly moisture retentive than in posts in drier areas or set in freely draining soils. Cross-sectional size and age of posts showed little correlation with frequency of severe decay, although the percentage of posts free of decay increased with decreasing age.
M E Hedley, J A Drysdale


Characterization of checks and cracks on the surface of weathered wood
2000 - IRG/WP 00-40153
The surface roughness of unweathered and untreated pine; unweathered copper chromium arsenate type C (CCA) - treated pine; weathered CCA-treated pine; and weathered CCA-plus-water-repellent (WR) - treated pine was evaluated by a stylus tracing method. Surface roughness parameters Ra, Rz, Rmax, Rk, Rpk, and Rvk were measured. Ra, Rpk, and Rvk were the most appropriate parameters for describing modifications on the wood surface. Ratios of the roughness parameters of the exposed (top) and unexposed (bottom) surfaces of the untreated, CCA-treated, and CCA + WR - treated wood samples were used to estimate the extent of the weathering damage on the exposed surface. The parameter ratios for the top and bottom surface were used to estimate the extent of the damage created by rain and sunlight on each piece of wood. This study shows that the stylus technique is appropriate to estimate the number and size of checks and cracks on wood surfaces after weathering.
D P Kamdem, Jun Zhang


Performance of Paraserianthus falcataria treated with ACZA, ACQ, CC or CCA and exposed in Krishnapatnam harbour, India
2005 - IRG/WP 05-30382
Paraserianthus falcataria (=Albizia falcataria) treated to two retentions with ammoniacal copper zinc arsenate (ACZA), ammoniacal copper quaternary (ACQ), ammoniacal copper citrate (CC) and chromated copper arsenate (CCA) was assessed over 34 months in a tropical marine waters at Krishnapatnam harbour on the east coast of India. ACZA treatment showed comparatively better resistance than CCA, ACQ and CC, while CC provided the least resistance to marine borer attack. Eight species of borers i.e. Martesia striata, M. nairi, Teredo furcifera,T. parksi, Lyrodus pedicellatus, Nausitora hedleyi, Bankia campanellata and B. rochi were recorded on test panels. Of these, M. striata, L. pedicellatus, T. furcifera and B. campanellata were the dominant species, while other species settled sporadically. The results suggest that copper based preservatives are less likely to perform well under extreme tropical exposures without arsenic.
B Tarakanadha, K S Rao, J J Morrell


Laboratory studies of CCA-C-leaching: influence of wood and soil properties on extent of arsenic and copper depletion
2002 - IRG/WP 02-50186
The extent which a wood preservative leaches is important for efficacy studies and environmental concerns. However, little information exists on the effect soil properties have on leaching. This study investigated leaching of stakelets which had been cut from five different southern yellow pine (SYP) sapwood boards then treated with CCA-C to a target retention of 6.4 kgm-3 (0.4 pcf). All stakelets were leached for 12 weeks by a common laboratory method in five different soils or water, with five replicate stakelets per board/soil. The physical and chemical properties of the five different soils were determined and the average leaching of the individual components of CCA was correlated with the various soil properties. Unfortunately, migration of a soil component (likely iron) into the stakelets from at least one of the five soils interfered with Cr determination by X-ray fluorescence; consequently, Cr depletion was not studied. Stakelets cut from one board tended to have lower Cu and As losses than the average of the other four boards for all five soils and water, and stakelets from another board tended to have higher Cu losses. Stakelets from all five boards had similar initial Cu and As levels, suggesting that the board effect was not due to differences in initial retentions. Cu loss was approximately equal to or greater than As loss for stakelets exposed to all five soils, but for wood leached in water the As loss was about twice the Cu loss. The soil property which was most statistically correlated to Cu loss was % Base Saturation (r2 of 77%), with Soil Acidity (pH) also important as a single predictor, and the Cr and Cu Soil Contents important as secondary predictors. The relationship between % Base Saturation (or Soil Acidity) and % Cu leached was not linear, however. A negative correlation was observed between Soil Cu Content and the metal leached from wood. The best factor to predict As loss was the Soil Cu Content, with Exchangeable K and % Silt also contributing to give an overall r2 of 72.3%. The % Organic Matter and the Soil As Content were also important as secondary predictors. We conclude that depletion of CCA is extremely complex and that Cu and As depletion appears to be influenced differently by the soil properties. Furthermore, extent of leaching can vary between different wood samples of the same species and even samples cut from the same board; thus, leaching data are not precise. Recommendations are given for a standard laboratory method for ground-contact leaching.
D Crawford, R F Fox, D P Kamden, S T Lebow, D D Nicholas, D Pettry, T Schultz, L Sites, R J Ziobro


Water repellency of wood treated with alkylammonium compounds and chromated copper arsenate
2000 - IRG/WP 00-30231
The comparative water sorption properties of southern pine treated with CCA and several alkylammonium compounds was evaluated for freshly treated wood and for wood after exposure in a fungus cellar. It was found that CCA imparts considerable water repellency to wood which is reduced somewhat after exposure to wet soil. With the exception of a long chain (C20 -C22) compound, the alkylammonium compound treated wood exhibited an increased water sorption rate and also exhibited increased total swelling.
D D Nicholas, A Kabir, A D Williams, A F Preston


Rapid fixation of Chromated Copper Arsenate (CCA) wood preservatives by microwave treatment
2000 - IRG/WP 00-40184
Rapid microwave heating of freshly chromated copper arsenate (CCA) treated timber indicates that rapid preservative fixation is possible within approximately 40 seconds. The leaching of CCA was evaluated using simulated rainfall. Cost analyses indicates that microwave fixation using an on-line conveyor belt fixation process with an output of 4m3/hour using a microwave power supply of 230 kW costs approximately AU$ 16/m3 for electricity costs of AU$ 0.077/kW-h. When electricity cost are AUS$ 0.017/kW-h the treatment costs are reduced to AU$ 10/m3.
G Torgovnikov, P Vinden, E Mapanda, P R S Cobham


Diffusion and interaction of components of water-borne preservatives in the wood cell wall
1988 - IRG/WP 3474
This study investigates the rates of diffusion and ultimate distributions of copper and arsenate components of wood preservatives in wood cell walls following vacuum treatment. Adsorption studies of copper on red pine (Pinus resinosa) and trembling aspen (Populus tremuloides) wood confirm the importance of cation exchange reactions on the ultimate distribution of copper in the wood substance and its strong dependence on pH of the treating solution. Formulations containing both copper and zinc preferentially adsorb or exchange copper relative to zinc. Under high pH conditions, the arsenate anion is significantly adsorbed into the cell wall. The combined adsorption and fixation of low pH CCA solutions is much slower than adsorption of high pH ACA and CZA formulations, but the reaction with wood is more complete. Diffusion coefficients were estimated for the movement of copper and arsenate components of ACA in cell wall material of both aspen and pine sapwood using a simple membrane model for non-steady state diffusion. The longer diffusion paths inherent in the diffuse porous hardwood (aspen) resulted in much slower equalization of the solute in the cell wall matrix than in red pine. However, in both species, equalization was achieved in a relative short time compared to accepted fixation times for conventional waterborne wood preservatives.
P A Cooper


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