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A new wood preservative based on polymerized complexes of aminotriazole with copper acetate
1998 - IRG/WP 98-30169
This paper presents the results of preliminary fungitoxicity tests as carried out on new polymerized complexes of aminotriazole with copper acetate (PCC) against Coniophora puteana and Trichoderma viride. Laboratory tests on wood confirmed the findings arrived at in the screening test on agar medium. Deep penetration into pine wood of compounds studied was observed and particularly so at humidity above the point of fiber saturation (up to 10 mm in manual treatment), as well as good fixation in wood. Together with quaternary ammonium compounds (QAC) a strong synergistic effect towards the microorganisms tested was evident. The formulations investigated in the present study seem promising for future use in the wood preservation. Their practical implementation may enable effective control of wood destroying agents.
K J Krajewski, A Lukasiewicz, J Wazny


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


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


Copper based wood preservative - A new approach using fixation with resin acids of rosin
2000 - IRG/WP 00-30249
Copper soaps with carboxylic acid groups of resin acids of rosin were shown to be potential long-term wood preservatives. The principle involved is the attachment of copper to the network formed by the inorganic part of the preservative (rosin) through the -COOH groups. The mechanisms of fixation have been studied, and it has been shown that this association could be obtained : (1) by forming the salt (a mix of rosin and NaOH where CuSO4 is added), and then impregnate (with a vacuum/pressure system) the wood with this product dissolved in ethanol, or (2) by using a double impregnation system with water solutions of the mix rosin-NaOH first, and a CuSO4 solution second, the salt being then formed within the timber. The biocidal mechanisms are based on the realease of Cu2+ by hydrolysis of the -(COO - )2Cu2+ when very humid conditions occur, this being reversible when wood moisture content is decreasing. Treated wood mini-blocks have shown good performances when leached, and biological tests assessed the good durability of such treated and leached timber.
C Roussel, J P Haluk, A Pizzi, M-F Thévenon


Efficacy of a novel copper-based organic solvent preservative in laboratory and fungus cellar tests
1995 - IRG/WP 95-30071
The efficacy of Chemicca 4, a novel copper-based organic solvent preservative, was compared with that of other LOSP in pure culture laboratory decay tests and with that of CCA and TBTO in a fungus cellar exposure. It was markedly superior to copper and zinc naphthenates at equivalent metal retentions in laboratory decay tests, and similar in activity to TBTO. After 60 months' fungus cellar exposure, Chemicca 4 at a retention of 0.03% mass/mass copper showed similar effectiveness to CCA at a retention of 0.31% mass/mass total active elements and was superior to TBTO at a retention of 0.09% mass/mass Sn. At 80 months' exposure Chemicca 4 at 0.16% mass/mass Cu was superior to CCA at 0.55% mass/mass total active elements. Extensive world-wide field testing of Chemicca 4 in above ground and ground contact environments both as an LOSP (above ground and ground contact) and in P9 oil (ground contact) is currently being undertaken.
M E Hedley, P N Maynard


Corrosiveness of metal by copper-based preservatives
2006 - IRG/WP 06-40329
The corrosive rates of 4 types of metal as well as epoxy-coated metal by a variety of preservatives derived from different copper source and ingredients were conducted in this paper. The main results shown that: CCA is less corrosive to red brass and Q235A steel than other copper formulations; Copper-based preservatives such as ACQ and copper azole derived from basic cupric carbonate or cupric hydroxide are much less corrosive to Q235A steel than these from cupric sulfate; Ethanolamine is less corrosive to Q235A steel than ammonia in ACQ derived from cupric hydroxide, while other ingredients are same; Epoxy resin coating could be used for protecting red brass, Q235A steel as well as zinc hot galvanized steel from preservative corrosion.
Ying Zhang, Mingliang Jiang


Use of the Digital Refractometer for the On-site Analysis of Copper-based Preservative Systems
2007 - IRG/WP 07-20371
In some counties, there are no on-site chemical analysis methods available for treatment plants to use to determine the key active ingredients in the preservative treatment solutions. The complexity of the sophisticated methodology; cost of analytical instruments and training required for operating these instruments in treating plant level are the reasons for lacking such practice. In this paper the development of a copper based preservative solution measurement method using a portable digital refractometer is presented. This method allows a very quick, easy and economical way to determine the preservative concentration of a treating solution at user sites for quality control purposes with reasonable accuracy. Discussion of the advantages and limitations of this method is included.
L Jin, T Cashman, A Preston, J Trompetter, H Trompetter


Termite resistance of copper-based preservative supplemented aspen strandboards
2012 - IRG/WP 12-30594
Termite resistance of aspen strandboards treated with various copper-based preservative systems was evaluated in field exposure tests. Five copper-based chemicals or zinc borate were blended into aspen furnish at three retention levels prior to pressing. Tebuconazole or 4,5-dichloro-2-N-octyl-4-isothiazolin-3-one (DCOI) were added as co-biocides to selected copper-based treatments. Sections from the panels were exposed to a colony of Formosan termite (Coptotermes formosanus) in an American Wood Protection Association Standard E21 test. Incorporating some combinations of copper-based preservative systems with organic co-biocides markedly improved the termite resistance of aspen oriented strandboard.
J J Morrell, C Vidrine, A Preston, L Jin


Scale-up of a chemical process for copper-based preservative-treated wood wastes recycling
2012 - IRG/WP 12-50286
In recent years, the development of appropriate wood waste disposal options has been encouraged by severe regulations and expensive fees associated with wastes landfilling or burning. An efficient and economically attractive leaching process was developed at laboratory scale (200 mL) for CCA-, ACQ- and CA-treated wood wastes recycling. This leaching process consisted of three leaching steps of 2 hours each, at 75°C with a sulfuric acid concentration at 9.8 g/L followed by three water-rinsing steps. The objective of this study was to investigate a possible application of this process to various mixtures of copper-based preservatives-treated wood wastes at pilot scale (80 L). The mixture of copper-based preservative-treated wood wastes was defined in order to represent wood waste stream evolution in the next decades. At the end of the leaching process, more than 98% of arsenic, 89% of chromium and 99% of copper were removed from a mixture of treated wood. Metal concentrations of the effluents produced during leaching steps were higher than regulations for effluents discharge in urban sewer. Leachate treatment by precipitation-coagulation was highly efficient and achieved more than 98% metal removal. The remaining arsenic, chromium and copper concentrations of the final effluents satisfied Quebec City municipal effluent discharge regulations. Chemicals consumption (sulfuric acid, ferric chloride, sodium hydroxide) depends of the mixture composition of treated wood. Remediation costs (total direct, indirect and general costs) ranged from $140 to $180 per metric ton of treated wood (ttw) depending on percentage of CCA-treated wood in the mixture. The use of wood residue for energy production represents an operating income estimated at $155/ttw (considering an energetic value of $13 per GJ).
L Coudert, L Gastonguay, J F Blais, G Mercier, P Cooper, P Morris, A Janin, N Reynier


Performance of untreated wood and wood impregnated with copper-ethanolamine based preservative solutions in Northern Adriatic Sea
2013 - IRG/WP 13-30623
Sea water applications of wood are among the most challenging ones. Impregnated wood is exposed to leaching and to variety of marine borers, Limnoria sp. and Teredo sp. being the most important. In the present research, durability of pine wood impregnated with copper-amine based preservative solution (Silvanolin) of different concentrations, exposed to the sea water, was investigated according to the EN 275 standard. Performance of Silvanolin treated wood was compared to performance of naturally durable wood (Quercus sp., Castanea sativa, Larix decidua). After 10 months, 18 months and 32 months of exposure, the samples were isolated and assessed. From the presented results it can be clearly seen, that durable wood species were completely degraded after 10 months of exposure. On the other hand, it is evident that Silvanolin prolongs the service life of exposed wood in the sea. The specimens impregnated with the lowest concentration of the preservative solution (cCu = 0.31 %) were only slightly decayed. At specimens, impregnated with higher concentrations of copper (cCu > 0.31 %) almost no defects were observed as a results of exposure to marine borers.
M Humar, M Petrič, J Adamek, B Lesar


An investigation of the effects of pre-steaming on the treatment of sawn spruce timber with Celcure A, a copper-chrome-arsenic preservative
1981 - IRG/WP 3150
Difficulties in the treatment of spruce using standard vacuum/pressure techniques with both water-borne and organic solvent preservatives are well known. We have evaluated the influence of steaming on treatability with a waterborne CCA preservative.
C R Coggins


Performance of Tebbacop in laboratory, fungus cellar and field tests
2000 - IRG/WP 00-30222
A novel organo-copper wood preservative ("Tebbacop") has been exposed to 12 years fungus cellar testing and 6 years above ground field testing. In the fungus cellar, Tebbacop at a retention of 0.053% Cu m/m oven dry wood out-performed CCA at a retention of 0.55% m/m oven dry wood. In above ground tests, L-joints treated to a Tebbacop retention of 0.012% Cu are performing as well as joints treated with TBTN to a retention of 0.08% Sn. In a slightly more severe decking test, 0.016% Cu as Tebbacop was more effective than 0.08% Sn as TBTN.
M E Hedley, D R Page, B E Patterson


Light organic solvent preservative treatment of glue-laminated radiata pine
1986 - IRG/WP 3380
The high permeability of radiata pine (Pinus radiata D. Don) is associated with ray-tissue and in particular the cross-field pits linking ray-tissue to tracheids. This pathway is absent in the tangential grain direction, leading to poor preservative penetration when treatment is restricted to the radial face - for example, timber fabricated into glue-laminated beams.
P Vinden


Conforming to european standards for preservative-treated timber: Specifying with confidence
2000 - IRG/WP 00-20194
A four-year collaborative study between four industrial partners and BRE has assessed timber treated by current UK industrial practices in the light of current European Standards. Data were collected for CCA and creosote treated timber components, and compared with the requirements laid out in EN351-1 and -2. A number of difficulties were encountered that have been described in previous IRG papers (98-20150, 99-20156), such as the poor reproducibility of chemical analyses and variable timber density. This paper describes the conclusions of our collaboration, focusing on the application of the findings and how to overcome any difficulties encountered. The data collected allowed the calculation of figures that have been submitted for inclusion into the UK's proposed national code for preservative-treated timber (DD239). An example is the recommendation of new minimum retention figures for creosote-treated commodities. This paper describes the factors that will enable UK specifiers to use the European Standards with confidence and greater understanding of how they map onto traditional methods of specification. In addition valuable lessons have been learnt applicable to the industry world wide.
E D Suttie, R J Orsler


Soft rot and bacterial decay in preservative treated eucalypt power transmission poles
1982 - IRG/WP 1155
Bacterial type decay was observed in CCA and PCP treated eucalypt power transmission poles. Detailed observations made with the SEM revealed bacterial colonisation and decay, especially in fibres. Plug samples taken from poles throughout Queensland were examined for preservative retention and presence of soft-rot decay. The severity of decay was different according to location, retention and species.
L E Leightley


Leaching of Active Components from Preservative Treated Timber. Stage 1: Semi-Field Testing
2004 - IRG/WP 04-20302
The project is aiming at finding realistic leaching rates from preservative-treated wood in use class 3 (above ground). The project focuses on developing a field trial method for investigating leaching. Panels are subjected to outdoor exposure under natural weather conditions at a test field at the Danish Technological Institute. The leachate is collected and monitored by chemical analysis of the active ingredients. The project is ongoing and the paper presents results from approximately 12 months’ of exposure. The study includes commercially available organic and inorganic fungicides using 4 different application methods: vacuum-pressure-, double-vacuum-, flow coat and supercritical treatment. Different test set-ups examine the influence of a number of different parameters. The results obtained from outdoor exposure will be compared with a laboratory test method (proposal of CEN/OECD, DOC TC38 WG 27 N039). The method investigated has proved to be useful in characterising the leaching behaviour from preservative-treated wood. The results from the present project are intended to serve as part of the basic documentation according to Directive 98/8/EC (The Biocidal Products Directive, BPD) for leaching of active ingredients in use class 3.
N Morsing, B Lindegaard


Proposed test procedure to determine the effect of timber substrate on the effectiveness of a copper/chrome/arsenic preservative in seawater
1975 - IRG/WP 411
R A Eaton


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


A wood preservative for the future: Copper dimethyldithiocarbamate
1994 - IRG/WP 94-30045
The development of a new wood preservative, copper dimethyl-dithiocarbamate (CDDC) is reviewed in this paper. CDDC is formed in situ by dual pressure treatments. Laboratory and field efficacy trials, physical and chemical properties of the preservative solutions and treated wood, and plant handling characteristics of the system are examined.
D K Stokes, M H Freeman, T L Woods, R D Arsenault


The influence of previous anti-blue-stain preservative treatments on the fixation of CC in spruce
1997 - IRG/WP 97-30134
Freshly cut and kiln dried spruce boards were treated with 4 different anti-blue stain preservatives (ABP). After a period of 10 days allowing the samples to dry and fixate, the samples were treated with CC (chromium, copper formulation) using a vacuum pressure cycle. After impregnation the wood was steam fixed. A submersion leaching test showed differences in the leachable quantity of copper and chromium. When related to the retention of both salts after impregnation, no differences could be found between samples previously treated with anti-blue-stain preservatives and untreated samples. However, the retention of CC diminished significantly by application of quaternary ammonium compounds.
M Van der Zee, W J Homan


Lignin-copper, a new wood preservative without arsenic and chromium
1992 - IRG/WP 92-3702
A more environmentally sound treatment for wood with preservatives containing no arsenic or chromium, has been developed and studied on a laboratory scale. The method involves a first step impregnation with an aqueous solution containing modified, water-soluble kraft lignin followed by a second step involving impregnation with a copper salt solution to give fixation of the lignin into a water-insoluble form and to achieve complementary protection. The two steps can be performed without intermediate drying of the wood in a conventional reactor for vacuum-pressure impregnation. The treatment has been shown to give good protection against degrading fungi, tunnelling bacteria and termites, and a lower growth of mould on the wood surface. Field tests (NTR test) indicate, after 4 years of exposure, very good protection gained by this new treatment. Fibre and particle boards made from wood fibres and wood particles, treated with this method show increased dimensional stability and rot resistance.
B Ohlsson, R Simonson


Copper based water-borne preservatives: The use of a thin section technique to compare the protection of wood by copper based preservatives against soft-rot and bacterial decay
1987 - IRG/WP 2286
This paper describes the techniques developed and gives examples of results obtained for the performance of copper based wood preservatives against both the bacterial and fungal hazards.
A M Wyles, D J Dickinson


The effective control of moulds on freshly impregnated wood
2004 - IRG/WP 04-30352
Beside natural timber it is known, that moulds can also groth at the surface of impregnated wood. This material shows “defects” like resistant dark spots or color changes and causes complaints. During the last years, the problem by moulds seems to increase. Laboratory studies were carried out to show the effect of impregnations against moulds. Wood samples (Pinus sylvestris L.) were impregnated by vacuum process using two industrial chromium-free copper based wood preservatives and a CCA-salt. Furthermore fungicides of isothiasoles as “mould-protection-chemicals” were added to the impregnation solutions. To consider an aging effect of this chemicals the modified solutions were stored at temperatures of 20°C or 40°C for 7 days. Direct after impregnation or after 4 weeks of conditioning the samples a mixture of moulds (Aspergillus niger, Penicillium cyclopium, Penicillium funiculosum, Paeciliomyces varioti, Trichoderma viride) were used to infect the impregnated material. The growth of moulds were observed after different times. The intensity of the growth of moulds was different during the first days, but already after 10 to 14 days all samples had complete moulds at the surface. Therefore none of the wood preservatives was protecting the samples against moulds. In the case of sample impregnations using wood preservatives with additional mould-protection-chemicals a various resistance of the impregnated wood on mould infection was found. The resistance depends on the combination of the type of wood preservative and the fungicide used. Differences caused by the aging test could be observed. It can be deduced from these results that this investigation method can help to answer questions concerning necessity, suitability and the appropriate type or content of mould-protection-chemicals in impregnation solutions.
G Cofta, K Lutomski, P Jüngel


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


A study of salt imbalances observed in recycled copper/chrome/arsenic preservative solutions in commercial practice
1987 - IRG/WP 3461
The study reported monitored tank solutions, sludge and other by-products using a standard CCA solution, when recycled. This recycling of the CCA solution is quite usual in between any commercial treatment schedules. Salt imbalances were observed and the possible reasons for such phenomena were studied. The paper discusses the procedure followed, the method of sampling the liquid after the charge and the analysis, to arrive finally at an aggregation and conclusion from the data.
V R Sonti, S Sonti, B Chatterjee


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