Your search resulted in 402 documents. Displaying 25 entries per page.
How to Document the Performance of Super-Critical Treated Wood in above Ground Situations?
2005 - IRG/WP 05-20316
The paper presents practical experiences from the preparation of a new preservative treated wood product for introduction to the market. The product in question is Superwood™, which is treated with organic biocides using CO2 in a supercritical state as a solvent. The question is how to evaluate the performance of a new product such as Superwood™ in order to get an acceptance on the market and fulfil the formal requirements. In the European Union countries, the EN 599-1 is the standard that needs to be complied when approving a new product for the market, but it only focuses on the toxic limit against representative decay fungi according to EN 113. However, decay test, above ground and other forms of field tests are optional, this is not in line with the traditional test philosophy in the Scandinavian countries. The open question is to which extent treatment to the level of the toxic threshold value also ensures a long service life and expected performance of the treated commodity. Superwood™ is evaluated using a strategy, in which basic laboratory tests are done to get the toxic value (according to EN 599-1) and in addition a number of field tests are done including accelerated testing in the tropics. These tests are focussed on the evaluation of the performance criteria such as durability and service life and maintenance requirements. These questions must be answered by the producer without having a full record of performance test for their new products. A short status on the test performed on super-critical treated wood (Superwood™) is presented. Based on a comparison between field test in Scandinavia and in the tropical Malaysia a service life of more than 25 years for a specific supercritical treated product is estimated. It is stated that the existing European standardisation system is insufficient when it comes to service life prediction. A number of important questions need to be addressed by the European standardisation system as soon as possible because the market and the public opinion change quickly due to environmental concern.
N Morsing, A H H Wong, F Imsgard, O Henriksen
Studies on accelerated ageing procedures with TBTO-treated wood
1985 - IRG/WP 2244
The efficacy of various procedures for accelerated ageing of organotin based wood preservatives in treated wood has been investigated. It was found that leaching of the treated wood samples in water according to the European Standard EN 84 was not satisfactory for organotin based preservatives and is probably also unsuitable even for other types of organic solvent preservatives. Keeping tributyltin oxide (TBTO) treated samples in a heating cabinet at 70°C for five weeks, however, had a considerable effect on the breakdown of TBTO and the subsequent decay test. Therefore, an ageing procedure involving a heating period should be considered for all organic solvent wood preservatives. The investigation also confirmed that elevated temperatures accelerate the degradation of TBTO and that there is a strong correlation between the percentage of TBTO in the wood and its resistance against decay.
J Jermer, M-L Edlund, B Henningsson, W Hintze
Accelerated ageing of preservatives in treated wood
1988 - IRG/WP 3476
New preservatives are tested in the laboratory and often in field tests before they are used commercially. Some preservatives, however, tested in the laboratory do not show the expected stability when used in service. The differences between laboratory tests and practical use can never be completely eliminated but must be minimized as far as possible by relevant testing methods. Studies of the effect of different accelerated ageing procedures on the chemical degradation and the wood preserving capacity of six different fungicides or combinations thereof have been carried out. Chemicals tested were tributyltinoxide (TBTO), tributyltin naphthenate (TBTN), furmecyclox, benzalkoniumchloride (AAC) + guazatin and pentachlorophenol. The ageing procedures included exposure of test specimens in a wind tunnel (according to EN 73), in an oven at 40°C, 60°C and 70°C, leaching (according to EN 84) and combinations of these procedures. The influence of the different accelerated ageing procedures on the chemical degradation and toxic effect of different fungicides was obvious and, for some procedures and chemicals, comparable with experiences from practice.
M-L Edlund, B Henningsson, B Jensen, C-E Sundman
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
Rapid leaching test
1991 - IRG/WP 2367
An accelerated test which is suitable for measuring the extent of metal fixation in both chromium and non chromium containing preservatives is described.
J A Cornfield, M Bacon, A Lyman, C Waldie, M R Gayles
The potential for accelerated ageing to determine the persistence of active ingredients in timber
2006 - IRG/WP 06-20323
Fast screening methods for evaluating the persistence of active ingredients in timber are proposed. This is an outline proposal which is intended to provoke discussion and further development of the methods. Reliable and accurate analytical methods are key to these tests.
L D A Saunders, M R Powell
Leaching of copper, chromium and arsenic from CCA-treated slash pine heartwood
1994 - IRG/WP 94-50020
Drying green slash pine with any of three high temperature drying schedules produced a product in which both the sapwood and the heartwood could be penetrated with CCA using a modified Bethell treatment schedule. Required H3 retentions were achieved in both sapwood and heartwood, from 200 litres per m³ charge uptake. Post-treatment fixation/drying was accomplished by three different regimes, including an accelerated fixation. Although acceptable preservative penetration and retention was achieved in the heartwood, arsenic fixation (as determined by both AWPA procedure E11-87 and U.S. EPA TCLP procedure) was inferior to that attained in the sapwood. TCLP leachates from 1 cm³ heartwood blocks contained up to 4.5 mg/l arsenic, very close to the maximum value (5.0 mg/l) currently permitted in Australia for arsenic waste disposal. Though there are clear advantages in achieving heartwood penetration, caution must be exercised to ensure that this step does not compromise the accepability of the product. No process modification could be accepted if it introduced possibilities of exceeding safe disposal limits for sawdust and offcuts, or building site contamination.
M J Kennedy, G Palmer
Délavabilité de bois ronds traités avec un sel CCA dans des conditions réelles de stockage. Incidence pratique de la fixation accélérée par étuvage. Impact effectif sur l'environnement
1993 - IRG/WP 93-50001-23
Un essai de terrain a été organisé pour mesurer concrètement, dans des conditions aussi proches que possibles des conditions réelles de terrain, les pertes effectives en produit de traitement lorsque le bois traité est soumis à des intempéries. L'essai a été conduit sur des bois ronds (poteaux), traités en autoclave par procédé Bethell avec un sel CCA de type C, avec comme finalité l'évaluation de la nature et des quantités de composés délavés en pratique, pour évaluer ainsi leur impact réel sur l'environnement au niveau du site de traitement. Compte-tenu des propriétés fixantes de ce type de produit, il était interessant d'identifier ces pertes à différents stades de la fixation, ainsi qu'après fixation compléte. Utilisant également les divers travaux et constats disponibles à ce jour sur les possibilités d'accélérer la fixation par l'étuvage, nous avons voulu observer et quantifier cette amélioration dans les mêmes conditions de terrain. Cet essai a été organisé et exécuté conjointement par le CTBA et la société FRANE BOIS IMPREGNES. Il conduit à 3 constatations principales: - Les pertes pratiques sont quantitativement nettement moins importantes que celles obtenues à partir des méthodes et échantillons de bois utilisés en laboratoire. - A l'issue et surtout au cours de la fixation les divers métaux se comportent de façon très différente, et on peut penser que la nature de la formulation a une importance notable sur ce comportement, même si dans tous les cas les quantités concrètement délavées restent faibles. - L'éuvage en sortie de traitement et dans des conditions adaptées permet d'obtenir spontanément, un résultat analogue à celui obtenu par un cycle de fixation traditionnel.
M Rayzal, F Larroze
Leaching of preservative components from pine decking treated with CCA and copper azole, and interactions of leachates with soils
2001 - IRG/WP 01-50171
Radiata pine decking was treated with CCA and copper azole preservatives to Australian H3 retention using conventional and modified Bethel schedules, and air-dried. Treated decking boards and durable hardwood controls were subjected to leaching in weather-exposed decks, and matching 19mm cubes were leached in extended AWPA E11-97 lab tests. Deck runoff and E11 leachate water was analysed after rain events and E11 change points. After 10 months, decks had lost up to 700mg Cu, 175mg Cr, 600mg As, 750mg B, 10 mg tebuconazole or 18000 mg tannin per square meter of deck, but flux rates had not yet reached zero for any component. Leaching from E11-97 blocks was much faster and greater than from the decks. Extending the leach period from 14 days to 50 days increased the amount of leaching by up to 40%. Even after 50 days, flux rates were measurable for most components. Deck leachates were applied to three soils using the draft OECD soil leaching column procedure. After elution, the soil was segmented and analysed. Although boron was more mobile than others, components tended to be retained in the topmost (first contacted) layer.
M J Kennedy, P A Collins
Leaching of active components from preservative-treated timber. Stages 2 & 3: Laboratory testing and comparison with semi-field testing
2004 - IRG/WP 04-20303
This part of the project is focussed on leaching from preservative-treated wood obtained by the laboratory test method CEN/OECD draft guideline, February 2003 ”OECD guideline for the testing of chemicals proposal for new guideline XXX. Estimation of Emissions from Preservative-treated Wood to the Environment: Laboratory Method for wood held in the storage yard after treatment and for wooden commodities exposed in Use Class 3 (not covered, not in contact with the ground).” Preservative-treated test specimens are emerged in water. The specimens are immersed two days a week in a 60 days period. On each immersion day 3 immersions are carried out. One sample is immersed in water 18 x 3 times. Each immersion takes one minute. Between each immersion the specimens are stored in climate chambers. Water (emissate) is retained for chemical analysis for active ingredient to determine the leaching. The study includes commercially available organic fungicides using vacuum-pressure treatment as an application method. The preservative used is the preservative used in Nordtest project 1582-02 named M1. The investigation includes two different periods of fixation, one with a long fixation period and one with a short fixation period of the active ingredient before the immersion testing. The results obtained from laboratory testing are compared with the semi-field exposure. The method developed for in-service testing has proved to characterise the leaching behaviour from preservative-treated wood. However, there is no good correlation between field-testing and the CEN/OECD laboratory testing method for the product involved.
N Morsing, B Lindegaard
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
Stability, performance and distribution of propiconazole (R 49362) in acceleratedly aged wood
1991 - IRG/WP 3647
The permanency of propiconazole (R 49362 - WOCOSENÔ technical - Janssen Pharmaceutica) in wood was examined in an 18 month storage test, an evaporative ageing study (EN 73), a volatilization stress experiment, and water-leaching studies (EN 84). The biological efficacy against two brown rot fungi: Coniophora puteana BAM Ebw. 15 and Gloeophyllum trabeum BAM Ebw. 109 was assessed according to the European Standard EN 113 with and without acceleratedly aged blocks of Scots pine sapwood (Pinus sylvestris L.). Propiconazole proved to be leach-resistant from treated wood. Evaporative ageing had very little effect on its biological performance. Chemical analyses of various Scots pine sapwood (Pinus sylvestris) samples used for EN 113 testing, showed that the concentration gradient in the outermost shell of the wood specimens was not altered by accelerated ageing stresses and that the active ingredient is evenly distributed in the wood substrate. These results indicate that propiconazole is suited for further development as a fungicide for pressure-treated timber.
A R Valcke, M Stevens
Comments on leaching in view of accelerated testing
1977 - IRG/WP 294
We developed an accelerated test for leaching at elevated temperatures (75-85°C). This test was used for the examination of 11 preservative formulations containing Cu, Zn and As. The data obtained from these experiments were compared with data on some formulations tested by ASTM standard leaching test. The method consists in making a large surface to volume ratio of wood from a treated block by cutting into sections approx 40 µm thick and in cyclic extracting preservative salt with a total of 250 ml of distilled water at the elevated temeratures for 24 hours. In conclusion, the new accelerated teet proved to be a fast method which provided reproducible dala on the leech-resistance of various inorganic preservatives. The data are comparable with data of traditional leaching tests at room temperature.
Comparative study on the leaching of wood preservatives between natural exposure and accelerating laboratory conditions
1999 - IRG/WP 99-50134
Impregnated specimens with CCA, ACQ, and BAAC were subjected to leaching tests. Specimens of 2x2x1 cm3 in size were used for the laboratory leaching test for 10 days according to JIS K 1571. Specimens of 25x1 x1 cm3 were used for outdoor leaching test for 6 months. Total leaching amounts of boron per cm3 of specimens treated with BAAC were 325 µg in the laboratory test and 206 µg in the outdoor test through the leaching periods. Those of Cu from ACQ and CCA treated specimens were 400 µg and 41 µg in the former test and 97 µg and 16 µg in the latter test. Leaching amounts in the laboratory test was much higher in every elements than those in the outdoor test without exception.
K Yamamoto, S Motegi, A Inai
Proposal for further work on accelerated ageing
1988 - IRG/WP 2314
A rapid field bioassay technique with subterranean termites
1983 - IRG/WP 1188
Details are summarised of a field procedure which is designed to ensure continuous exposure to a replenishing termite biomass. After pre-baiting to determine the presence and identification of a termite hazard, test specimens (35 x 35 x 250 mm³) are installed vertically in the ground adjacent to and in contact with bait specimens of the same dimensions and interconnected by susceptible feeder strip.
C D Howick, J W Creffield
Influence of different fixation and ageing procedures on the leaching behaviour of copper from selected wood preservatives in laboratory trials
2003 - IRG/WP 03-20264
The paper focuses on the role of different parameters, such as fixation, sample size, wood species, and leaching in internationally standardized ageing procedures for wood preservatives from Europe, Japan and the United States. The leaching protocols used were EN 84, JIS K 1571 and AWPA E11 protocols. The wood species were Scots pine, Sugi and Southern Yellow Pine respectively. Three types of commercially important copper-based wood preservatives were used as model formulations, namely copper/copper-HDO, ammoniacal copper/quat and CCA. The most important factors determining the extent of copper leaching in the different lab trials were the sample size (volume/surface ratio) and the fixation conditions prior to leaching. On the other hand, the wood species and the leaching protocol itself were found to have only minor influence on the copper leaching rate in the test methods included in this study.
J Habicht, D Häntzschel, J Wittenzellner
IRG Working Group II. Co-operative leaching test (letter to collaborators)
1974 - IRG/WP 240
J W W Morgan
Japan's comments on ISO/DIS 12583-1/2
1996 - IRG/WP 96-20100
The paper describes an accelerated field test for the evaluation of timber preservative formulations against subterranean termites. The method has been adopted by the South African wood preservation industry as a screening method for the approval of wood preservatives for use under SA conditions. The method which is based upon the fungal cellar test offers a rapid means of evaluating the comparative performance of new wood preservative formulations in an environment that accurately reflects field conditions.
P Turner, D Conradie
Leaching of the new boron based biocide from coated wood
2001 - IRG/WP 01-30267
We investigated leachability of the new boron based biocide - a complex of an amine and boric acid - from vacuum impregnated spruce wood samples. It was determined by the standard ENV 1250-2 procedure that the new biocide is susceptible to leaching so from the water borne as well as from the ethanol borne boron containing preservative treated wood. Leaching may be retarded by application of surface coatings. The ability of a surface finish to prevent leaching is correlated to its water vapour permeability.
M Petric, M Pavlic, F Cadez
The accelerated field simulator (= fungal cellar)
1982 - IRG/WP 2170
G C Johnson, J D Thornton, H Greaves
Effect of water repellents on leaching from CCA treated wood
1995 - IRG/WP 95-50044
CCA treated fence boards brushed with a water repellent finish had consistently lower leaching losses of all CCA components compared to the rate for matched samples without the water repellent. These results are after 12 cycles of simulated rainfall in the laboratory (1800 mm rainfall total) and four months of natural rain exposure in Toronto.
P A Cooper, R MacVicar
Problems of fixation of CCA-preservatives in palm-wood
1985 - IRG/WP 3338
Palm-wood may be used for posts and poles where it needs proper treatment for long time use. Based on observations by W. Killmann on low CCA-fixation in palm-wood, samples of Jubaea-palm grown in a Greenhouse at Hamburg, have been treated in two different series with a 4% solution of CCA-type B. After 1-16 weeks of storage the blocks were split into sticks of 1-2 mm² and leached. In all series 50% of the chromium and copper content of the individual blocks was leached independent of the time of storage, whereas simultaneously treated pinewood samples showed complete fixation after 4 weeks of storage.
H Willeitner, K Brandt
Leaching of components from water-borne paints and fungitoxic effects
1995 - IRG/WP 95-20062
Water-borne model paints, acrylics and alkyd emulsion paints, of known composition were leached according to a procedure modified in accordance with ASTM 6271.1. The effectiveness of fungicidal compounds in the painted specimens before and after leaching was evaluated with a biotest in which Penicillium brevicompactum was used as a test fungus. The leaching of the fungicide Troysan Polyphase according to the biotest varied to a high extent depending on differences in paint composition. Fungicide efficiency in relation to paint formulation and fungicide mobility in a paint film is briefly discussed.
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