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Characteristics and quantity of impregnated wood waste in Germany
1995 - IRG/WP 95-50041
The disposal of wood waste in Germany is one of the main problems not only for the wood preservation industry but also for all concerned with wood waste. Data on characteristics and quantity of wood waste are still needed. Based on criterions given in a previous paper (IRG/WP 93-50006), several assortments have been characterized with regard to their hazardous potential and their logistical aspects. Results show that mixed assortments are those with the highest quantities. Each year about 2 Mio t of wood from demolition of buildings and from building sites have to be disposed. This accounts much more than the whole field of timber from landscape (ca. 220.000 t/a), crossties (ca. 6085.000 t/a) and poles (ca. 25.000 t/a). Timber from landscape, however, has a high hazardous potential and is hard to collect because of its broad distribution (e.g. private households). For assortments with small annual quantities (e.g. cooling towers, wooden silos) specific disposal structures are not realistic. At present most of the assortments cannot be reused or recycled either due to their hazardous potential or to their unfavourable disposal structures. For timber from landscape as well as for timber from demolition of buildings incineration in specific plants should be preferred.
A Voss, H Willeitner


Possibility and problems of characterizing treated wood after service with regard to disposal
1993 - IRG/WP 93-50006
For the disposal of wood waste under ecological conditions, information about its hazardous potential and the logistic aspects for its handling is needed. The main criterion to evaluate the hazardous potential besides the determination of the type and quantity of active ingredients in the wood will be the degree of mixture with different treated or untreated timber. Assortments can be homogeneous (e.g. creosoted ties), partial homogeneous (e.g. poles with various chromium containing types) and mixed (e.g. wood from demolition of buildings). To improve the possibilites of re-using, recycling or disposal, a comprehensive survey on the structure of ownership, the kind of accumulation and the quantities of waste wood will provide with basical information. The evaluation of these logistical aspects can help for example to avoid mixed assortments, to decide whether separation as well as concentration may be useful and possible and to choose a suitable disposal method. As conclusions unsolved problems are identified.
A Voss, H Willeitner


Screening potential preservatives against stain and mould fungi on pine timber in Zimbabwe
1995 - IRG/WP 95-30063
The search for environmentally and toxicologically safer chemicals for use in the timber preservative industry against stain and mould fungi has been intensified during the past few years. Results of field tests with two chemicals previously evaluated in the laboratory are presented. The conventional sodium pentachlorophenate was the more efficacious chemical against stain and mould fungi, providing up 90% control at a concentration of 2.5%. A potential alternative, Stopstain a borate-based chemical, gave results only slightly better than the untreated control timber, at a concentration of 5%. Unless the environmental cost and toxicological hazards of traditional chemicals are highlighted the newer and safer chemicals will be reluctantly accepted by industry as they are regarded as being prohibitively expensive.
A J Masuka


Possible regulatory status of treated wood waste and implications
1998 - IRG/WP 98-50101-07
In relation to the European Community or the French regulations, treated wood waste can get two different regulatory status: <<recycled product or fuel>> or <<waste>>. Then, into the waste status, two categories are possible for these residues: <<domestic waste and assimilated>> or <<hazardous waste>>. These different status and categories are important for the environmental issue of treated wood waste management. But they also can have strong economical implications, linked to the waste management cost on one hand and on the materials image on the other hand. On the basis of the EC regulations, up to now, no treated wood waste is namely quoted as <<hazardous waste>>. However, through the classification criteria defined by different EC directives, creosote or heavy metals treated wood waste could be to considered that way. The technical arguments for such a classification and the practical implications are discussed.
G Deroubaix


Recent soft-rot research in softwoods and hardwoods
1980 - IRG/WP 1108
The purpose of this paper is to describe briefly the current status of our research on soft-rot fungi. The work to be discussed is still in progress and any results described must be regarded as provisional.
J A Butcher


Report of field test results for dichloro-n-octyl-isothiazolone: A potential new wood preservative
1988 - IRG/WP 3495
In a previous report (IRG/WP/3306) we presented preliminary laboratory test results on 4,5-dichloro-2-n-octyl-4-isothiazolone (RH 287). Laboratory data indicated toxic threshold values for RH 287 ranging from 0.37 to 0.50 kg/m³. In this report we present field test results on an IRG L-joint test and an in-ground stake test for RH 287, pentachlorophenol and biocide free test units. (a) L-joint test: After 39 months exposure (Starkville MS.) units pressure treated with 0.05 kg/m³ RH 287 rated 9.7 out of 10. Units dip treated in a 0.5% ai solution of RH 287 rated 10 out of 10. Biocide free controls exposed in the same series rated 5.3 out of 10 after 39 months (b) Stake test: After 48 months exposure in two southern US test plots stakes treated with neat RH 287 in toluene at 4.6 kg/m³ rated between 8.6 to 8.8 out of 10 for decay and 9.1 to 9.8 out of 10 for termite attack. Biocide free control stakes rated O out of 10 for decay and 1.1 to 4.8 out of 10 for termite attack after 48 months. RH 287 continues to show promise as a potential new wood preservative. Results to date were obtained in samples treated with neat RH 287, Formulation of RH 287 into treatment systems specifically designed for above ground or ground contact applications should only improve the already excellent activity seen with RH 287.
D E Greenley, B M Hegarty


The potential of 2-deoxy-D-glucose as an active ingredient in wood preservation
1999 - IRG/WP 99-30205
2-deoxy-D-glucose (2-DOG) is a potential active ingredient against wood decaying fungi. When dissolved in water, it can be used in pressure treatment of wood. Thereby the wood is protected from attack by wood decaying fungi. A concentration of 1.5% (mean retention 9.7 kg/cubic meter sap-wood) is adequate for brown rot fungi, and 3% (mean retention 19.5 kg/cubic meter sapwood) will also provide protection against white rot fungi. 2-DOG is easily soluble in water, and is therefore easily leached from the wood upon completion of the preservation process. Different types of fixa-tion methods have been tried and evaluated. It is possible to produce 2-DOG by the hydrolysis of chitin, a constituent of the exterior skeleton of shellfish and insects. There is a potential for exploita-tion of this waste product provided by the crab and shrimp industry. The yield of 1 kg of fresh shrimp is 75 g of 2-DOG.
O V Frederiksen, A P Koch


Screening potential termiticides: Some thoughts and suggestions on methodology
1988 - IRG/WP 1363
While laboratory bioassays on the efficacy of potential termiticides against subterranean termites continues both to dominate and influence research efforts, suggestions are presented for the need to develop laboratory bioassays that more closely simulate "natural conditions". Not only is this considered desirable, but it will offer more confidence in laboratory and field evaluations and their analyses.
J R J French


Investigation of the fixation in wood of chromated zinc chloride and copperised chromated zinc chloride preservatives
1976 - IRG/WP 372
A biological method of evaluating the extent to which CZC and CCZC preparations are retained in wood in terms of the potential protection which they afford against destruction by Merulius lacrymans (dry rot) is given. CCZC is recommended for protection of wood under moderate leaching conditions, while the use of CZC under such conditions is not recommended.
V N Sozonova, D A Belenkov


Potential toxicants for controlling soft rot in preservative treated hardwoods. Part 4: Evaluation of combined diffusion and toxicity
1979 - IRG/WP 2129
A large number of inorganic and organic preservatives were evaluated as potential soft rot control chemicals, by their degree of inhibition of fungal growth after allowing them to diffuse through a 6 mm thick wood slab. The tests were inoculated with wood powder from soft-rotted CCA treated poles. Pentachlorophenol was unable to diffuse quickly through the wood slab, although formulations with hexylene glycol showed some promise. Hydroxyisoxazole gave good results as did a number of other organic materials including "Busan 30", "Busan 52", "Permapruf T", sodium oxinate, sodium trichlorophenate, "Gloquat C", „Hyamine 1622", butyl icinol, and the commercial bandage materials "Osmoplast" and "Wolman pole bandage". Of the inorganic materials tested, good results were obtained with "Basilit BFB", with other Cu-F-B formulations including "Blue 7", and with fluoroborate and fluorosilicate preparations in general. Arsenates also showed some promise.
E W B Da Costa, O Collett


Leaching of inorganic wood preservatives – Investigating the relationship between leachability, dissociation characteristics and long-term leaching potential
2003 - IRG/WP 03-50199
Estimation of the leaching properties of preservative components is greatly affected by the leaching test method applied since not all methods equally consider the physical components responsible for leaching. These include: wetting of the wood and penetration of water (affected by dimensions, amount of end grain, permeability, duration and nature of water exposure); solution of preservative components into available moisture (affected by component solubility, wood moisture content, temperature, etc.); diffusion of components out of wood (affected by product dimensions, permeability, direction of movement, moisture content, temperature, nature of the diffusing species, etc.); and re-drying of the wood between moisture exposures. Aggressive leaching of finely ground wood provides a measure of the ultimate amounts of preservative compounds available for leaching while analysis of the equilibrium dissociation or solubility of components in free water in the wood provides information on their effective concentration which drives the diffusion process. Combining this information with a simple diffusion test should allow the estimation of potential risk from leaching over a wide range of specified conditions. In this paper, the leaching of several inorganic wood preservatives is compared and related to dissociation of preservatives within the wood structure and diffusion out of wood.
L Waldron, Y T Ung, P A Cooper


A case for adopting a standardised protocol of field and laboratory bioassays to evaluate a potential soil termiticide
2003 - IRG/WP 03-20275
The rationale for adopting a new approach to the field testing of potential soil termiticides is advocated on the grounds that current testing methods are limited to termite bioassays and do not address quantitatively the persistence and bioavailability of soil termiticides to foraging subterranean termites over time and in different soil types. Furthermore, the present testing regimes assume field situations of uniform high termite hazard across field sites. Our testing procedures require the random sampling of soil cores from test soil pads (500 x 500 mm) at several geographically different locations. The soil cores from treated and untreated soil pads are returned to the laboratory and the soil residues in half of the samples examined for each year of test by gas chromatography. The bioavailability of termiticide residues in the remaining soil samples are evaluated by termite bioassays using the field collected subterranean termite, Coptotermes acinaciformis (Froggatt). Both tunnelling distance and mortality are used as indicators of termiticide activity and availability. This paper compares the traditional soil test methods with our new approach, which addresses the problems of security with longevity of test, variability of termite hazard levels at different field sites, and a practical method for managing variables in assessing potential soil termiticides. Importantly, this technique prevents the direct destruction of natural populations of subterranean termites or the indirect contamination by contact from soil residues of termiticides applied in and around active termite colonies.
J R J French, B M Ahmed


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


Agenda Special Seminar: Screening techniques for potential wood preservative chemicals
1978 - IRG/WP 2115
IRG Secretariat


Wood preservation in Turkey
1982 - IRG/WP 3216
The report reviews the forestry potential of Turkey and also the historical background of wood preservation in the country. The wood preservation industry in Turkey is mainly concentrated on the treatment of poles and railway sleepers. There is no official body responsible for wood preservation activities, and therefore its promotion depends mainly on the voluntary research efforts carried out by the universities and the Forest Research Institute. Present standards are inadequate to meet contemporary standards of wood protection used in other countries. These should be completely revised and updated. Its forest products potential and geographical location combine to give Turkey a great advantage for exportation of its timber to the Middle East countries. But first of all Turkey has to solve its own problems of promoting a productive industry and efficient wood preservation.
R Ilhan, R Cockcroft


N-tritylmorpholine as a potential marine wood protectant against teredinids and pholads - A preliminary evaluation
1983 - IRG/WP 497
The molluscicide, N-tritylmorpholine, is effective in eradicating certain fresh water snails, the intermediate hosts in the transmission of schistosomiasis in man. This preliminary study shows that N-tritylmorpholine is also active against wood-boring marine mollusks. Fine sapwood impregnated with this morpholino compound was not damaged by teredinids or pholads while exposed at two marine sites in Panama. Because of its extreme insolubility, N-tritylmorpholine becomes a very specific toxicant, affecting only those marine mollusks (teredinids and pholads) which bore into the treated wood.
J D Bultman, K K Parrish


Evaluating the potential of modified wood for use in marine environments using a short-term laboratory bioassay
2004 - IRG/WP 04-10525
Chemically modified wood may be an alternative to preservative treated timber for marine structures. In this study a screening laboratory test using the wood-boring isopod crustacean Limnoria quadripunctata was used to assess the durability of chemically modified Pinus sylvestris, Pinus radiata and Picea sp. Most of the treatments used a combination of one of two of types of the resin dimethyloldihydroxyethyleneurea (DMDHEU) and phosphobutane tricarboxylic acid (PBTC). Untreated Pinus sylvestris sapwood was used as a non-durable comparison. Small test sticks from different types of modified wood were prepared and leached in seawater for 8 days prior to the experiment. A wood stick with a Limnoria and 4 ml of seawater was placed in each 12mm diameter well of a cell culture chamber. The number of faecal pellets produced by the animals was measured under these forced feeding conditions, and activity and mortality was recorded. With some treatments, no faecal pellets were produced, with others more faecal pellets were produced than with untreated Pinus sylvestris. Non-production of faecal pellets was sometimes due to mortality, but in some treatments there were also evidence of antifeedant effects as there was no evidence of acute toxicity Limnoria. However, some moribund animals were observed in these treatments and there was significant reduction in the number of pellets produced, so chronic toxicity may be suspected. The Arkofix type of DMDHEU gave significantly higher protection against borers than DMDHEU NG. A dose-dependent suppression of pellet production by PBTC was also detected.
L M S Borges, S M Cragg, M van der Zee


A potential anti-sapstain chemical for sawmills
1984 - IRG/WP 3300
Several biocidal formulations were tested under laboratory conditions in order to discover an alternative antisapstain chemical to chlorophenoxides. The formulations tested were experimental water solutions containing a quaternary ammonium chloride, a commercial fungicide and/or a sodium salt of some carboxylic acids. The effect of sodium carbonate and borax decahydrate in mixture with a quaternary compound was also examined. The best cost-effectiveness was obtained with trimethylcocoammoniumchloride in combination with a sodium salt of a branched-chain aliphatic acid. This finding was later confirmed in pilot and mill scale tests.
I A Linderborg


The chemical analysis and biological evaluation of wood extractives as potential timber preservatives
1995 - IRG/WP 95-30090
Work involved the biological performance of water and organic solvent soluble extractives of four naturally durable wood species, namely; Matumi, Tamboti, Sneezewood and the Turpentine tree. These timber species are known to be naturally durable against termites and fungi (±25 to 35 years). The extractives were evaluated against termites and fungi using impregnated pine pencil stakes in field tests and soil burial trials over a 2 year period. C13NMR analysis of extractives isolated from the wood was carried out to try and identify the key chemical components which might impart durability with a view to prediction of new potential wood preservative formulations.
P Turner, D Conradie


Evaluation of substituted isothiazolone as a potential new wood preservative
1984 - IRG/WP 3306
Laboratory decay tests were carried out with isothiazolone (4,5-dichloro-2-n-octyl-4-isothiazolone-3-one) treated wood. This compound was found to be extremely effective against three common wood decaying brown-rot fungi, exhibiting toxic threshold values in the range of 0.37 to 0.50 kg/m³. For the white-rot fungus, Coriolus versicolor, the toxic threshold values for treated pine and sweetgum were 0.42 and 2.3 kg/m³, respectively. In an unsterile soil test (soft-rot fungi), a toxic threshold value of 0.48 kg/m³ was obtained, which indicates a high degree of effectiveness against these fungi.
D D Nicholas, A F Preston, D E Greenley, S V Parikh


International standards and the biocide debate - Potential contribution
2000 - IRG/WP 00-20196
Downstream the European 98/8/EEC directive on biocides, a working party of O.E.C.D. has been developing a tremendous work to put together the background information necessary to assess wood preservative efficacy, environmental and human exposure. Standardization may contribute to those efforts, using traditional experience and methodology. Among them, the hazard classification system may be extended to human beings and their environment, in all situations of uses. While primary exposure to biocides seems to be a matter related to classes of processes, the situation differs with secondary exposure to treated wood, related to use categories: in principle, the doses are already restricted to targets in a given class. Additionally, those uses have been , until now, practically limited to construction products. The first need is to extend the hazard class system to all kinds of biocidal wood preservation and their related uses. A methodology is proposed to get access to biocide concentrations and flows in priority compartments, assessment of intake by non-targets and their ratio to no-effect values in order to quantify safety factors. This route could allow to select further priorities for risk reduction at the pre-marketing stage.
G Ozanne


An evaluation of the potential of ion mobility spectrometry for detection of organic wood preservative components in solutions and treated wood
1994 - IRG/WP 94-20038
For the disposal of wood waste under ecological sound conditions information about its hazardous potential is required. Until now, no highly sensitive rapid analytical methods are available for the detection of wood preservatives under industrial process conditions. Preliminary experiments showed that Ion Mobility Spectrometry (IMS) could be a promising method for rapid detection of organic preservatives in waste wood. A number of organic wood preservatives (i.e. Al-HDO, Quat, Armoblen, Azaconzole, HCH, Creosote, DCFN, Furmecylox, MBT, Methyl-parathion, PCP, Permethrin, K-o-PP, TBTO, TCMTB and Tebuconazole) was studied. Both solutions and treated wood samples were analyzed with IMS. IMS-spectra are generated by analyzing the ionized volatile compounds of the samples. The time each ion needs to proceed to a detector is specific and can be characterized by a comparable Ko value, the so-called reduced mobility constant. A &apos;fingerprint&apos; of the wood and the chemicals is obtained. IMS was able to distinguish between most of the preservatives. However, in wood, some of the chemicals could not be determined. So far the results are provisional and further investigation is needed.
A Voss, J N R Ruddick, W J Homan, H Militz, H Willeitner


A study of the decay type potential of seven soils
1992 - IRG/WP 92-1539
The aim of this experiment was to determine the significance of the fungal inoculum potential and physico-chemical properties of five field trial test site soils, a garden compost known to cause white rot in copper treated fence palings, and soil from a zone between 2 and 15 centimetres from a CCA treated post with brown rot, in causing differential decay type in Pinus radiata and Poplus deltoides sapwood blocks. Two blocks of each species were buried in non-sterile soil in jars with the upper transverse face level with the soil surface. A block of the same species was placed, with the transverse face upwards, on the top of each buried block. Six replicate jars per soil type were used. A second set of jars containing 90% sterile potting compost and 10% non-sterile soil, for each of the seven types, was set up as described above. Soil moisture content was adjusted to, and maintained at, 30% of the dry weight. Decay type and weight loss was determined for each block after twenty weeks incubation at 25°C. Considerable differences of decay type and weight loss edited between the 100% and 10% soil regimes, soil type, and timber species. These differences and their significance are discussed.
R N Wakeling


Commercial potential of the four-cycle method for the impregnation of green beech sleepers in Yugoslavia
1975 - IRG/WP 347
This paper was presented to the Conference on Wood Protection held in Sarajevo (Yugoslavia) in 1973. The paper was based partially on the report prepared by J. Struhar and G. F. Franciosi, who were appointed in 1972 as FAO consultants to demonstrate the new impregnation process for green beech sleepers in Yugoslavia. The so-called 4-cycle method was developed at the State Forest Research Institute in Bratislava (Czechoslovakia). The demonstration treatment was carried out at the Kolasin plant, where the double Rueping method is currently used. Comparing the double Rueping method with the 4-cycle method, the author discusses the possibility of introducing the new method into existing impregnation plants in Yugoslavia. Analysis has shown that the production costs of impregnated beech sleepers under the new method would cost 44 Dinars per m³ more for sleepers, or 530,000 Dinars annually (based on the Kolasin plant capacity). On the other hand, formation of tyloses and doat in "white" sleepers during seasoning, estimated to be 10%, would be completely avoided, saving 972,000 Dinars annually at the Kolasin plant. Besides the stock of untreated sleepers would be considerably reduced which would enable the saving of working capital at the Kolasin plant of about 2,5 mill of Dinars. It is also expected that due to higher creosote oil consumption and its even spreading through the wood, the service life of sleepers would be extended by 10 years (from 30 to 40). In such a way the Yugoslavian Railways would decrease the purchasing and installation costs by about 10 Dinars per m³ of sleepers or 1,270,000 Dinars annually (in 1972 USA$ 1 equalled 15 Dinars).
N Vidovic


Termite resistance of Malaysian and exotic woods with plantation potential: Laboratory evaluation
1998 - IRG/WP 98-10280
The resistance of selected Malaysian woods to attack by the representative aggressive subterranean termite Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) was evaluated in four-week, no-choice laboratory tests. This is part of an ongoing effort between the Forest Research Institute Malaysia and the University of Hawaii to document the termite resistance of Malaysian timber species of potential value in plantation forestry. Several of these tree genera also occur in Hawaii, or could potentially be of value as well in forestry efforts in the Hawaiian islands. Species included in the present report are: acacia (Acacia mangium), batai (Albizia falcataria), casuarina pine (Casuarina equisetifolia), Araucarian pine (Araucaria cunninghamii), sentang (Azadirachta excelsa), both Malaysian-grown and Burmese-grown teak (Tectona grandis), kempas (Koompassia malaccensis), tualang (Koompassia excelsa), Caribbean pine (Pinus caribaea), Scots pine (Pinus sylvestris), and rubberwood (Hevea brasiliensis). Of these, Burmese teak, kempas, tualang, and casuarina pine proved most resistant to termite attack. Malaysian teak and sentang demonstrated somewhat less, but still significant termite resistance. Sentang is a relatively pest-free tree of interest for plantation forestry, and was also quite toxic to termites. The remaining tree species were very susceptible to termite attack, and would require protection in the field and treatment of the resulting wood products. Correlation of these laboratory results with data from field studies in Malaysia will provide a comprehensive profile of the termite resistance of these timbers.
J K Grace, A A H Wong, C H M Tome


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