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La rôle de l'expert dans l'évaluation toxicologique
1990 - IRG/WP 3589
C Boudene


Bait box technique for remedial subterranean termite contro
1995 - IRG/WP 95-10115
The bait box technique, as described in this paper, was first used as a method to apply the dust toxicant, arsenic trioxide, to large numbers of aggregated subterranean termites. Over the last twelve years or so the technique has been refined, and in recent years, gained acceptance as an alternative subterranean termite control measure by members of the Australian pest control industry. This baiting technique is particularly timely in Australia, given that the organochlorine insecticides are to be banned in termite control strategies in all states as from June 1995, except for a period of extension in the Northern Territory. Details of box construction, placement, and application of the dust toxicant are outlined. Suggestions are offered in the use of this technique with other dust toxicants, such as inclusion compounds and microbial spores pathogenic to termites, and bait toxicants.
J R J French, B M Ahmed, D M Ewart


Incomplete fixation of chromium in the pre-treated wood with a solution of copper and arsenic compounds
1995 - IRG/WP 95-50052
Ponderosa pine wood thin sections were treated with a combination of chromium, copper, and arsenic chemicals. The wood sections was analyzed by electron spin resonance spectrometry (ESR) and X-ray photoelectron spectrometry (XPS) to elucidate the mechanism of fixation of the chromated-copper preservatives. The wood subjected to the two-step treatment with copper and arsenic followed by chromium exhibited a strong Cr(V) ESR signal. However both Cr(III) and weak Cr(V) signals were observed in wood subjected to the one-step treatment containing chromium, copper, and arsenic. XPS spectra also supported the Cr(V) formation in the former treatment. The further chromium reduction from Cr(V) to Cr(III) for samples treated in two steps did not proceed very well during the fixation period of 3 months. Copper arsenate formed in the wood could disturb the interaction of chromium with the wood. These results indicate that re-treatment of wood with chromium containing preservatives may result in incomplete fixation of chromium.
J N R Ruddick, K Yamamoto, F G Herring, P C Wong, K A R Mitchell


Removal of copper, chromium and arsenic from CCA treated wood using boron compounds
2005 - IRG/WP 05-50230
This study evaluates the copper (Cu), chromium (Cr) and arsenic (As) removal from CCA treated wood using boron compounds such as boric acid, borax (sodium tetraborate), and Timbor (DOT, disodium octaborate tetrahydrate) at varying (3 and 5%) concentrations. Remediation processes were taken at 1, 5 and 10 day intervals. Metals in remediated chips or sawdust were then analyzed using ICP and XRF. Results showed that, higher level of Cu was removed followed by As and Cr. The percentage removal of metals was higher in saw dust then chips. Borax at lower concentration (3%) removed 41.4%, 18.3% and 44.9% of Cu, Cr and As, respectively, in 10 days while at higher concentration (5%) 65.8%, 55% and 55.8% of Cu, Cr, As, respectively, were removed for the same period. Boric acid removed 39.7%, 15.5% and 35.6% at lower and 50.7%, 48.9% and 50.9% of Cu, Cr, and As at higher concentration, respectively, while DOT was not an effective extractant. Distilled water extraction removed 27.3%, 23.7% and 22.8% of Cu, Cr and As respectively. In case of chips, borax removed 30.3%, 19.7% and 24.9% of Cu, Cr, and As; boric acid removed 25.5%, 12.2% and 19.5%; DOT removed 22.8%, 10.8%, 14.2% and distilled water 17.7%, 11.1% and 10.2% of Cu, Cr, and As, respectively. Increasing the concentration of solution has greater effect on elements removal. Among the three compounds tested, borax removed higher levels of metals compared to boric acid and DOT.
B Tarakanadha, T Hata, S N Kartal, W J Hwang, Y Imamura


Recovery of copper, chromium, and arsenic compounds from the waste preservative-treated wood
1991 - IRG/WP 3651
In Japan, about 40 percents of waste wood is incinerated and the residue is dumped into the landfill site. The waste preservative-treated wood, which is mixed in nontreated wood, is incinerated in the same way, too. However, it will cause the serious problems that the gases contained with high concentration arsenic compounds are discharged from the smokestacks of the incineration facilities and the toxic water with high concentrations of copper, chromium, and arsenic compounds is discharged around landfill sites because the residue contains a lot of these compounds. To solve these problems, it is necessary to develop a method to recover these compounds from the waste preservative-treated wood. In this paper, extraction experiments of copper, chromium, and arsenic compounds from treated wood were carried out and evaluated as a method to recover these compounds. Through the experiments, suitable extractant, its concentration, and extraction conditions such as the temperature, extraction time, and the size of test wood piece were obtained. As the results of these experiments, Cr, Cu, and As compounds in the test wood piece were completely recovered into the extractant under the suitable conditions.
A Honda, Y Kanjo, A Kimoto, K Koshii, S Kashiwazaki


Thermal decomposition behavior of CCA-treated wood for safe disposal and the safe recovery of heavy metals through pyrolysis
2006 - IRG/WP 06-50238
If we could estimate the chemical changes in heavy metals by temperature in chromated copper arsenate (CCA)-treated wood during pyrolysis, it is expected that we could solve the environmental problems of heavy metals, which may occur during pyrolysis, and therefore, the thermal decomposition behavior of effective elements of CCA-treated wood was examined to find a safe disposal method. First, CCA-treated wood was combusted at a temperature that prevents volatilization of arsenic compounds, and the arsenic compounds were extracted from carbonized wood. Then, it was considered how to recover heavy metals from chromium compounds and copper compounds. The Thermo Gravimetric Analysis (TGA) result of CCA-treated wood showed that arsenic (III) oxide was volatilized into the atmosphere at 300? and arsenic (V) oxide was volatilized at 800?. When heavy metals were recovered from the carbonized-treated wood after thermal decomposition of CCA-treated wood at 300?, which could suppress the volatilization of arsenic compounds, it was relatively easy to recover copper and arsenic while it was difficult to recover chromium from the carbonized-treated wood.
Dong Won Son, Dong-heub Lee, Sun-hae Cheon, Myung Jae Lee


A discussion on causes, effects and remedies of arsenic pollution of groundwater in Bangladesh
1998 - IRG/WP 98-50102
This paper includes possible causes, effects and remedies of arsenic pollution of groundwater in Bangladesh, extracted mostly from the international conference held in Dhaka in 1998. Next possible key steps have been suggested based on scientific principles and experience. The release of arsenic from underground sediment would be due to excessive mechanical forces, geochemical and geobiological reactions. Arsenic free water will cure acute patients and will save future generations. Use of suitable organic chemicals, organic matters, biological control system would be widely acceptable for supplying arsenic free water. Other natural sources of water can be used easily and safely without mechanical and chemical processes. The problems of chronic patients would be solved genetically, enzymatically and nutritionally.
A K Lahiry


Electrodialytic remediation of creosote and CCA treated timber wastes
2002 - IRG/WP 02-50190
There is a growing concern about the environmental issue of impregnated timber waste management, since an increase in the amount of waste of treated wood is expected over the next decades. Presently, no well-documented treatment technique is yet available for this type of waste. Alternative options concerning the disposal of treated wood are becoming more attractive to study, especially the ones that may promote its re-use. Inside this approach, the electrodialytic process (ED) seems a promising technique for removal of preservative chemicals from treated wood waste. The method uses a direct electric current and its effects in the matrix as the “cleaning agent”, combining the electrokinetic movement (mainly due to electromigration, but also electro-osmosis and electrophoresis), with the principle of electrodialysis. This work reports results from the application of the electrodialytic process to an out-of-service Portuguese creosote and CCA-treated Pinus pinaster Ait. railway sleeper and pole. The behaviour of the process is described and the main results discussed. The average removal rate, estimated in accordance with prEN 12490, for creosote from treated timber waste was around 40 %.. For CCA treated timber waste, experimental conditions that could optimise the process efficiency (e.g. current density, time) were studied. The highest removal rates obtained until now, in our studies, were 93 % of Cu, 95 % of Cr and 99 % of As for sawdust using 2.5 % oxalic acid (w/w) as the assisting agent. For CCA treated wood waste in the form of chips, the best removal rates obtained until now were 84 % of Cu, 91 % of Cr and 97 % of As.
E P Mateus, A B Ribeiro, L Ottosen


Laboratory decay test of Burmese in and kanyin treated with three wood preservatives
1982 - IRG/WP 3210
Laboratory decay tests were performed on samples of In (Dipterocarpus tuberculatus Roxb.) and Kanyin (Dipterocarpus alatus Roxb. and Dipterocarpus turbinatus Gaertn f.) pressure treated with three wood preservatives - copper arsenic additive (CAA - a variation of ammoniacal copper arsenate), Arquad C-33 (a waterborne quaternary ammonium formulation), and tributyltin acetate (TBTA) dissolved in ethanol. Pressure treatments with each preservative involved a 0.5 - 1 hour vacuum followed by a 4 hour period of pressure. This resulted in a very variable treatment because of the inherent difficulty in treating these woods. The decay tests entailed a slightly modified form of the AWPA M10-77 standard soil-block test using three brown-rot and three white-rot fungi. The untreated In and Kanyin samples were moderately susceptible to decay though weight losses were very variable and some samples of Kanyin (usually the densest and least permeable) were naturally resistant. At the concentrations tested CAA was the most effective in reducing weight losses incurred in the soil-block tests. TBTA was successful in controlling decay caused by all but two of the test fungi. It is suggested that preservative retentions for TBTA conforming to those included in the Candadian standard for bis (tributyltin) oxide would exceed the toxic limit for all the fungi tested
J N R Ruddick, R S Smith, A Byrne


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


Preliminary results of investigations on screening test of chemical compounds suitable for the preservation of lignocellulosic materials against biodeterioration
1976 - IRG/WP 262
This paper investigates the possibilities of reducing the time needed for the determination of the effectiveness of chemical compounds from the point of view of their eventual application to lignocellulosic materials for preservation against decay and soft-rot.
K Lutomski, S S Neyman


Dimensional stabilization of wood with dimethylol compounds
1987 - IRG/WP 3412
This study showed that a substantial degree of dimensional stability can be imparted to wood by crosslinking with low concentrations of dimethyloldihydroxyethyleneurea. It was demonstrated that by selecting the right catalyst system the cure temperature can be reduced to the point that strength loss of the treated wood is minimized.
D D Nicholas, A D Williams


Insect resistance of preservative treated tropical plywood against Lyctus
1990 - IRG/WP 1453
Seven plywood types composed of tropical wood species, vulnerable to Lyctus, were treated with various commercial water-borne and oil-borne preservatives. A wide range of preservative retentions was obtained by treating boards with dip treatment, steeping, double-vacuum and vacuum-pressure impregnations. Selected samples were subsequently tested for their insect resistance against Lyctus africanus during 6 to 8 months according to European Standard EN 20. All control samples were attacked, except one Obeche plywood exhibiting only 50% attack. Water-borne preservative solutions containing arsenic, boron or fluoride could not prevent attack at common retention levels for interior use e.g. lower than 5 kg/m³. Quaternary ammonium compounds showed no insecticidal efficiency, up to 3 kg/m³. TCMTB at 1.5-1.7 kg/m³ proved to be able to reduce slightly the susceptibility for insect attack. Organic insecticides gave the best results, with nearly no attack for plywood treated with lindane or cypermethrin. In spite of a preservative uptake of 25 to 30 kg/m³, endosulfan only could reduce attack by 50%. Protection by permethrin at 0.1% a.i. required a retention of 28 kg/m³. Besides the fact that variability in wood species and composition of the plywood are leading to different retention levels, variation in penetration and distribution of a.i., and as a consequence to a different insect resistance of the impregnated boards, some poor results were directly related to inadequate insecticidal activity and/or concentration of a.i. in some commercial formulations for Lyctus control.
J Van Acker, M Stevens, M Pallaske


Chemical compounds from Eperua falcata and Eperua grandiflora heartwood and their biological activities against wood destroying fungus (Coriolus versicolor)
2005 - IRG/WP 05-30373
The chemistry analysis of the compounds present in dichloromethane and ethanolic fraction as well as bioassays enables to understand the durability differences of Eperua falcata and Eperua grandiflora. The principal distinction between these two species is the acidic subfraction of diterpenoic extract, which is antifungic in Eperua falcata when tested in in-vitro conditions. This study also enables to show that ethanolic fraction plays an important role in the mechanism of natural durability. It also reports the first isolation of cativic acid in Eperua falcata wood.
N Amusant, C Moretti, B Richard, E Prost, J M Nuzillard, M-F Thévenon


Observations on the colonization of freshly-felled timber treated with prophylactic chemicals by mould and sapstain fungi
1989 - IRG/WP 1394
Field tests using freshly felled pine sapwood were set up to determine the effectiveness of a range of antisapstain compounds and to study the problems of colonization by mould and sapstain fungi. Differences were recorded both in the overall performance of the compounds and also their selectivity in controlling specific fungal types. These results were found to be useful in gaining a better understanding of biocide - fungal interactions.
G R Williams, D A Lewis


Leaching of copper, chromium and arsenic from CCA-treated Scots pine exposed in sea water
2000 - IRG/WP 00-50149
A laboratory leaching trial combining a static and a flowing seawater system was carried out to measure the leaching rates of copper, chromium and arsenic from the surface of Scots pine panels vacuum-pressure treated to 3, 6, 12, 24, and 48 kgm-3 CCA. Untreated and treated panels were exposed in flowing seawater for up to 8 weeks followed by 2 weeks submersion in static seawater which was taken for analysis. The study revealed a leaching hierarchy of Cu>Cr>As which supports the findings of other investigators. Over the 8 week leaching trial there was a time-related decrease in the rate of copper and chromium loss. Over the first week of leaching in flowing seawater, the rates of loss of copper and chromium decreased to between one-half and one-seventh, followed by lower rates of leaching over the remaining period of the investigation. In contrast, the rate of loss of arsenic from the wood appeared to increase slightly over the same period. The data are compared with minimal leaching rates of toxins from the surface of anti-fouling paints and are discussed in terms of the fouling communities which are established on Scots pine panels treated to similar target retentions.
C J Brown, R A Eaton


Fungicidal and termiticidal effectiveness of alkylammonium compounds
1983 - IRG/WP 3232
This paper is related to effectiveness of several AAC's against wood decay fungi and termites by Japanese standardized test methods.
K Tsunoda, K Nishimoto


Some thoughts on the future strategy for eradicating Serpula lacrymans from a building
1989 - IRG/WP 1405
We now have a clear view of the mechanism of translocation of nutrients in the mycelium of Serpula lacrymans which is one of the physiological processes underlying the remarkable capacity of this fungus to spread through a building. Here the elements of the mechanism of translocation are dissected out to suggest avenues which might be followed in the search for new ways for eradicating the fungus from buildings.
D H Jennings


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


Editorial corrections to Document No: IRG/WP/304
1972 - IRG/WP 305
Anonymous


Studies of the distribution and degradation of tributyltin naphthenate in double-vacuum treated wood
1983 - IRG/WP 3230
The effects of forced solvent evaporation by kilning redwood (Pinus sylvestris) that has been double-vacuum treated with tributyltin naphthenate (TBTN) have been investigated. Contrary to previous studies reported, it has been shown that forced evaporation can have a considerable influence on the losses of the fungicide. It has been found that, whether the solvent is allowed to evaporate slowly or the evaporation is forced by kilning, the TBTN breaks down considerably in freshly treated wood. In view of the implications of this work for the long-term effectiveness of TBTN further studies are called for.
J Jermer, M-L Edlund, W Hintze, S V Ohlsson


Fluorine compounds for wood preservation
1971 - IRG/WP 304
Fluoride compounds have gained a considerable importance in wood preservation, especially in Germany and some other countries of Europe. They are used as single compounde or in mixtures of different compounds. In the International Research Group on Wood Preservation which continues the activities of a former OECD-Group, it was moved to prepare a survey on fluorides in wood preservation together with other papers on the present state of knowledge of wood preservatives and methods of application. Monofluorides and silicofluorides have been used in the field of wood preservation for about 60 years and special development and application of hydrogen fluorides have been going on for 30 years. Much scientific work has been carried out on fluorides and much experience in practical use is available. It thus seems to be useful to briefly summarise the information on this group of compounds in wood preservation. Due to the voluminous literature, ie some 270 papers which are cited in the references, only an introduction into the problems and main results but not a detailed review of the publications is possible. The subjects dealt with in the publications are indicated in the references. With some exceptions the brief survey is limited to the compounds and mixtures without chromium which remain leachable in the wood. Questions of toxicity to human beings, animals and plants are not discussed in this paper.
G Becker


The 1999-2000 annual report for the IRG - Wood Preservation in Egypt
2000 - IRG/WP 00-40188
The wood destroying insects in Egypt are belonging to several families of Coleoptera, Lepidoptera and Isoptera. Imported woods are treated by The Agricultural Quarantine or the authorized companies. The materials used for protection as pre-treatment are the same of the treatment. They are Bromide methyl, copper or fluoride salts, organo-phosphorus compounds, pyrethroides, creosote or creosodial. Any preservative should be evaluated by the Ministry of Agriculture before recommendation. Of the preserved woods are Lumbers, sleepers and poles, woods used in constructions and furniture as well. The woods used in furniture, constructions or woodworks are mostly imported from Sweden, Russia, Finland or Korea. Several kinds of woods are imported as Picea sp., Pinus sp., Phagus sp. Local woods used are limited in kinds and amount, as Casuarina sp., Eucalyptus sp., Ficus sp., Acacia sp. Treated woods are potentially increasing in use. There are neither restriction for the use of treated woods, not any regulation concerning the desposal of these woods.
S I M Moein


Improved PEC preservatives with added biocides
1985 - IRG/WP 3322
Biocidal chemicals have been incorporated into formulations within the broad framework of pigment emulsified creosote (PEC) to provide novel potential multi-purpose preservatives. Preparations of PEC plus TCMTB, Boracol 40, copper ethanolamine nonanoate, Quatramine 80, arsenic trioxide, Troysan Polyphase, and CCA have been formulated and assessed for preserving ability in soil-jar and Accelerated Field Simulator tests. In addition, a cationic oil-in-water emulsion preservative combination of PEC and CCA (PECCA), and an anionic formulation of TCMTB with PEC (PECBUS) have been manufactured in 400 L quantities to treat hardwood pole stubs and pine posts. The results indicate the potential of these improved second generation PEC-based preservatives to provide low-creosote containing treatments able to protect commodities against biodeterioration as well as provide dry, clean surfaces.
H Greaves, C-W Chin, J B Watkins


X-ray analysis of selected anatomical structures in copper/chrome/arsenic treated wood
1973 - IRG/WP 320
Application of analytical electron microscopy to problems in wood preservation has been very limited. Indeed, less than ten workers appear to have published their results using the technique, and of these' only two papers deal with energy dispersion procedures in the scanning electron microscope; the others employ the more familiar wavelength dispersive methods of the electron probe.
H Greaves


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