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Utility, deterioration and preservation of marine timbers in India
2005 - IRG/WP 05-40314
Timber is extensively used in India in the marine environment for various purposes due to its several advantages over modern materials. Infact, its use is increasing in recent years, finding wider and wider applications and this scenario is not going to change in the near future. Though, the bio-deterioration problem is found very severe in tropical waters, still indigenous methods are widely employed for the protection of fishing craft and the present level of chemical treatment is well below 5% of total timber used. This is due to socio economic problems of the potential timber user groups, unavailability of treatment plants in the coastal areas, lack of awareness in user groups, etc. In this paper, types of fishing craft used in the country, timber uses in the marine environment, bio-deterioration losses, research conducted on bio-deterioration aspects at various places and methods applied for the protection of wooden structures are presented.
B Tarakanadha, M V Rao, M Balaji, P K Aggarwal, K S Rao


Biological Treatment to Improve Wood Product Quality and Durability - Fifteen Years of Effort and Experience at FPInnovations-Forintek Division
2009 - IRG/WP 09-40444
Wood plays an important role in the world economy. However, wood is subject to attack from wood-degrading fungi and insects and durability and quality of wood products are becoming increasing concerns for consumers. Development of effective and low environmental impact technologies to improve wood product quality and durability will be required to address these concerns. The application of a biological treatment to wood products is an example of one such technology. During the past fifteen years, a series of research projects were conducted at FPInnovations–Forintek Division to explore and develop various biological technologies and treatments to improve wood quality and durability against mold, stain and decay. These projects included 1) biological protection of logs and green lumber from mold, stain and decay; 2) biological pre-drying of wetwood lumber; 3) biological treatment to improve wood panel durability; 4) biological modification of wood to reduce resin use in panel manufacturing; and 5) biological incising to harden wood. This article summarizes the significant technical breakthroughs and findings made in these studies.
Dian-Qing Yang


Methods for Studying Penetration Depth of Wood Protection Products
2010 - IRG/WP 10-20432
EN 152 is an accepted standard in Europe for measuring how deep a wood protection product penetrates into the surface of treated pine wood. The method has provided consumers with a wide assortment of products that meet the specifications outlined in the standard. Because the test takes 8 or more months to carry out, artificial ageing procedures have evolved in order to standardize and speed up the procedure. Small changes in a formulation will often change a products physical parameters and especially its ability to penetrate into wood. It is therefore desirable to develop a method that can measure changes in a product’s penetrability quickly and accurately. A method is described where wood cores are drilled from treated wood, then sliced in 100 µm thick discs. Discs are then placed on nutrient agar plates seeded with conidia from Aspergillus niger. Plates are incubated for 24 hours and zones of inhibition are measured. It is believed that if a fungus is growing on the disc the biocide level will not exceed that of the fungus minimum inhibition concentration (MIC). In water based acrylic systems penetration depths are often less than one mm and it can impact the performance of a product if that changes. The procedure described in this study can show if penetration of a preservative product has been increased or reduced in as little as 24 hours.
K Hansen, L Sites, D D Nicholas


Bio-friendly preservative systems for enhanced wood durability - the first periodic report on DURAWOOD
2015 - IRG/WP 15-30677
The objective of the paper is the DURAWOOD scientific project carried out within Polish-Norwegian Research Programme, which lasts from September 2013 till August 2016. The aim of the project concentrates on the developing of a new, eco-friendly and biocide-free wood protective systems as an alternative to traditional, commonly used preservatives or coatings, containing biocides. Several wood preservatives containing traditional biocides are no longer desired on the market, due to the stricter toxicological requirements and an increasing ecological awareness of consumers. Therefore, formulating new wood protective systems, based on natural compounds, harmless to humans and the environment, is of the principle interest. On the other hand, it will also facilitate a longer period of carbon capture in wood, which will limit the greenhouse effect. Life cycle assessment (LCA), which is planned to perform for the selected model formulations, is a good example for an attempt to explain the interest. Besides, the implementation of novel solutions in wood protection will make it possible to use low quality wood material to manufacture high quality products (e.g. siding or cladding materials). In this manner such eco-friendly wood protection will be also a key factor reinforcing climate protection. The aim of this paper is to present some selected results gained so far. The model wood protecting systems were based on natural (alkaloids, propolis, plant oils) and synthetic (organosilicones, imidazoles) components as well as on neutral inorganic chemical - potassium carbonate. They were used individually or as a formulation for wood treatment. Wood samples made of Scots pine were treated by soaking or vacuum method and were subjected to mycological and fire tests. The so far results show that aminosilanes and mixtures thereof with natural oils are potential wood preservatives against microfungi and wood destroying fungi. Formulations containing aminosilanes, natural oils and potassium carbonate are potential wood fire retardants. It was also found that the most effective alkaloids were cytisine derivatives and caffeine. The highest antifungal activity among tested imidazoles was achieved by AK17 (1,10-di(3-hydroxymethylpyridinium)decanedibromide). The results of chemical analysis present evidence of interactions between compounds of the model formulations and wood chemical components.
B Mazela, M Broda, W Perdoch, L Ross Gobakken, I Ratajczak, G Cofta, W Grześkowiak, A Komasa, A Przybył


Effects of Bio-oil Obtained from Laurel (Laurus nobilis) Residues on Biological, Physical, and Mechanical Properties of Treated Wood
2016 - IRG/WP 16-30692
In this study, the effects of bio-oil obtained from Laurel (Laurus nobilis) residues on biological (decay, insect, termite resistance), physical (water absorption, tangential and radial swelling), and mechanical properties (MOE, MOR and CSPG) of treated wood samples were studied. The bio-oil used in this paper was produced by the help of fixed bed reactor type pyrolyzer. GC/MS analysis showed that the main constituents of bio-oils are furan compounds. The results indicated that the samples treated with bio-oil had lower water absorption and swelling rates than that of the control group. The lowest water absorption result (45%) for the bio-oils studied was obtained for the samples treated with 20% bio-oil after 48 h exposure in water. Decay resistance of treated wood samples with bio-oil against white rot (Trametes versicolor) and brown rot (Postia placenta, Gloephyllum trabeum, Coniophora puteana) fungi was carried out according to EN 113. Prior to decay test, samples were leached according to AWPA E11. Decay test results showed that treated samples had some efficiency against white and brown rot. In addition, bio-oil at the tested concentration did not give an adequate protection against insect and termite test. Strength test results show that treatment with bio-oil generally decreases mechanical properties of wood.
S Akbas, A Temiz, N Terziev, M H Alma, S Palanti, E Feci


Decay resistance of wood treated with bio-friendly preservative systems
2016 - IRG/WP 16-30698
Due to more restrictive toxicological requirements and increased ecological awareness of consumers, wood preservatives containing biocides are no longer desired on the market. Therefore, research on new environmentally friendly formulations is of great importance. One of the possible solutions is to develop new preservatives based on natural substances, which are harmless to humans, animals and the environment, while biologically active. The aim of the study was to develop new biocide-free preservative systems which increase wood resistance to wood-decaying fungi. The following silanes: [3-(2-Aminoethylamino)propyl]trimethoxysilane (AATMOS), (Aminopropyl)triethoxysilane (APTEOS), and (Aminopropyl)trimethoxysilane (APTMOS); caffeine, natural oils and potassium carbonate were chosen as components of new protective formulations, which were planned to be an alternative for traditionally used biocides. Samples of three different wood species (pine, spruce, and poplar) were treated with the new preservative systems and exposed to brown-rot fungus Coniophora puteana and white-rot fungus Coriolus versicolor according to EN113 or EN839 standard. The obtained results show that wood treated with the water-based formulation consisting of silanes and caffeine (2% caffeine + 5% AATMOS, 2% caffeine + 5% APTEOS) demonstrated the highest resistance to the test fungi. Wood mass loss after exposure to fungi was 1%. All wood species treated with this formulation achieved index 1 (“very resistant”) within durability class acc. to EN-350 standard.
B Mazela, G Cofta, W Perdoch, L Ross Gobakken, P Kwaśniewska-Sip


Bio-friendly wood protection systems - resistance to mould and blue-stain fungi
2017 - IRG/WP 17-30713
With stricter restrictions on the use of biocides and increasing environmental awareness there is a pronounced need for effective bio-friendly protection systems in the wood preservative and wood coating industry. One of the possible pathways is to exploit and utilize natural substances with active biological effects. Silanes, caffeine, natural oils and potassium carbonate were chosen as compounds in 16 different formulations intended as wood protection systems. The aim of this study was to test the resistance of the selected protection systems against mould growth and growth of blue-stain fungi. Combination of caffeine and amino functional silanes showed good resistance towards blue-stain fungi when applied to pine and the same was found for the combination of linseed oil and amino functional silanes. Some indications of resistance towards mould fungi were also detected for the same chemical combinations.
L Ross Gobakken, W Perdoch, B Mazela, P Kwaśniewska-Sip, G Cofta


Biocontrol of wood decay insects and nematodes as an alternative to traditional chemical treatments
2018 - IRG/WP 18-10914
The protection of wood has been defined until relatively recently, as the application of a chemical to increase its durability. On the other hand, society is becoming more and more demanding in terms of the use of products which have the minimum ecological impact. This has led many countries to reduce the list of biocidal products that can be used (European Biocides Regulation), therefore it is necessary to seek sustainable alternatives. The use of biological control agents can constitute a good alternative to traditional biocides, due to their economic and ecological advantages.
L Robertson, J F Galván, F Llinares, R Viñambres, M T de Troya


Liquefied wood polyols: Ecofriendly bio-based preservative for sustainable protection of wood from Termite attack
2018 - IRG/WP 18-10916
The major problems encountered in both indoor and outdoor utilization of wood are biological decay due to termite. The modification of wood with liquefied wood polyols has been found to be effective against termite attack. The liquefaction of wood aims to utilize woody wastes which are being generated during primary and secondary processing of wood in wood based industry. One of promising approaches to utilizing these lignocellulosic wastes is its liquefaction for developing natural products having potential to use as bio based wood preservatives against biological enemies of timber like termite. In this study, woody waste recovered from wood based industry has been liquefied in different liquefying media in defined reaction condition to produce chemically active liquid which is being as wood preservatives for protection of wood from termite. The level of impregnation of preservative in wood was estimated by determining the weight percent gain and the modification was characterized by FTIR and NMR spectroscopy. The efficacy of bio-based preservatives on treated wood against termites was evaluated. The accelerated wood sample were impregnated with liquefied wood polyols and tested as per Indian Standard No.4873:1968 in graveyard for 24 months exposure in field conditions against termite. The periodical observation has been collected and after 24 months accelerated termite test shows promising results both in visual observation and percentage weight loss as compare to initial condition and control sample. Investigation shows that percentage weight loss of accelerated treated wood sample which is ranges from 5- 20% of its initial weight. The increased termite resistance of modified wood indicates liquefied wood polyols which bio- based wood preservatives has a promising potential reagent for modification of wood against natural wood decaying agents. The liquefaction of wood opens up new avenues for utilization of woody waste for development of organic preservative which is environmental friendly and also helps in reducing carbon foot print from the Earth to provides better greener and sustainable world for coming generation.
A Kumar, A John, T S Mehra, A K Pandey, S Singh Chauhan


Liquefied wood polyols: a bio-based preservative for protection of wood from fungal decay
2018 - IRG/WP 18-30725
The liquefaction of wood is one of promising approaches in utilization of woody waste which is generated during primary and secondary processing of wood and liquefied wood having various application including bio-based preservatives. The biological degradation of wood due to fungi is the major problem encountered in indoor and outdoor utilization of wood. In this study, woody waste recovered from wood based industry was liquefied in phenol, glycerol and polyethylene glycol as liquefying media under defined reaction condition to produce chemically active liquid. These liquefied woods were used as preservatives and its efficacy were evaluated after impregnation of wood against fungi. The level of impregnation of preservative in wood was estimated by the weight percent gain after impregnation and the changes were characterized by FTIR and NMR spectroscopy. The melia wood samples have been impregnated with liquefied wood and untreated wood sample were also exposed to a brown rot (Polyporus meliae and Oligoporus placentus) and a white rot (Trametes hirsuta (Wulf. Ex Fr.) and Trametes versicolor (L. Ex Fr.) fungus for 16 weeks under laboratory conditions as per IS: 4873 (Part I), 2008. Investigation indicated that phenolated wood inhibited fungal growth in the wood. The fungicidal traits of phenolated wood showed higher antifungal efficacy against both white rot and brown rot of wood whereas wood samples impregnated with liquefied wood in glycerol and polyethylene glycol shows insignificant effects on growth of fungus and is similar infested as to control samples. The increased fungal resistance of phenolated wood indicates liquefied wood polyols has a promising potential for treatment of wood against natural wood decaying agents. The liquefaction of wood opens up new avenues for utilization of woody waste for development of organic preservative which is environmental friendly and also provides greener and sustainable option to the world for present and coming generation.
A Kumar, G Vijaylakshmi, S Singh Chauhan


Chemical defense of trees and wood natural durability: from protection to valorization
2019 - IRG/WP 19-10943
Natural durability of wood is defined as “the inherent resistance of wood against various wood-destroying organisms” (European standard EN 350-1). This property is due in particular to heartwood extractives. However, the wood natural durability is included in a wider defense system, and other organs such as bark and roots also host protective compounds. Studying the mechanisms on which global chemical defense relies can give insights into the tree functioning, but also inspire new solutions for scientific and technical innovation. Firstly, we will highlight the link between the role of volatile organic compounds (VOCs) in tree chemical defense and the optimized production of economically valuable products such as essential oils. We will then present previous works performed by our team aiming at understanding the chemical resistance mechanisms of durable woods against fungi, to eventually isolate and identify antifungal compounds that could be used for the treatment of human fungal diseases, in the context of a bio-inspired approach. Lastly, we will show that the use of wood residues obtained from naturally durable trees transformed by the timber industry can be a sustainable strategy to develop innovative products for human well-being or health.
E Houel, D Stien, N Amusant


Chemical composition and performances of slow pyrolysis by-product from sugarcane bagasse for wood protection
2020 - IRG/WP 20-30752
Pyrolysis distillate or bio-oil, a by-product of biomasses’ slow pyrolysis in the char-making process, has been traditionally used as bio-pesticides by Asian farmers. Due to its large composition of bio-active chemicals, bio-oil obtained from various biomass has become of interest in many applications, including wood protectants. This study aims to characterize the chemical composition of bio-oil obtained from the slow pyrolysis of sugarcane bagasse at the temperatures of 400 °C and 500 °C, along with the efficacy test against two Basidiomycete fungi (Coniophora puteana, a cubic rot, and Trametes versicolor, a fibrous rot) and subterranean termites (Reticulitermes flavipes). The test on wood was also conducted by impregnating the bio-oil to the beech wood samples. Treated samples were dried at various temperatures (ambient, 40°C, 60°C, 80°C and 103°C), and leached before being exposed to termites R. flavipes. Gas Chromatography-Mass Spectrometry (GC/MS) analysis revealed that bio-oil is composed mainly of oxygenated compounds such as carboxylic acids, alcohols, aldehydes, ketones, furans, and anhydrosugars. In contrast, about 40% of the bio-oil consisted of water. At the concentration of 0.25% (v/v), bio-oil were observed to be able to inhibit the growth of both Basidiomycete fungi, when performing inhibition growth tests in Petri dishes. Further, no termites survived when exposed to a filter paper with a 10% concentration of bio-oil. All the wood samples have been shown durable against R. flavipes. However, bio-oil remains leachable from the wood, which indicates that future studies should be conducted in order to find out how to decrease its leachability.
F D Boer, M-F Thévenon, J-M Commandre, M Fournier


From wood protection to health protection: larvicidal potential of formulations containing Sextonia rubra wood residues extract against Aedes aegypti mosquitoes
2020 - IRG/WP 20-10968
French Guiana is a French overseas territory almost entirely covered by Amazonian rainforest and characterized by its incredible biodiversity. Several woody species harboured by this tropical forest are exploited sustainably for timber industry. They are commercialized notably for carpentry and outdoor applications because of their remarkable natural durability. Among them, stand Dicorynia guianensis Amshoff (Angélique), Qualea rosea Aubl. (Gonfolo rose), Ruizterania albiflora (Warm.) Marc.-Berti (Gonfolo gris) and Sextonia rubra Mez. Van der Werff (Grignon franc), representing around 80% of the global exploitation volume. This industry however generates large volumes of wastes, in particular because more than 50% of the ligneous material are lost between cutting down and sawing. Moreover, the strong demographic growth (around 2.5% per year) in French Guiana will lead to a notable increase of the need for timber, in construction as well as for energy, and the amount of induced wood wastes will increase concurrently. Sawdust residues are used currently only for biomass energy factories, but owing to the presence of molecules displaying interesting biological properties, wood residues and sawdust definitively deserve more attention. In recent years, a rising interest in value-added forest products, and in particular wood extractives, has indeed been observed, with the aim of reducing the lost generated by the forest industry due to undervalorized biomass components (Royer et al. 2013a, Khan et al. 2014, Borges et al. 2019). It is therefore relevant to integrate a new step in forest resources valorisation, putting the bio-refinery concept into practice (Royer et al. 2013b).
E Cervil, N Amusant, E Wozniak, I Dusfour, J-B Duchemin, D Azam, M Coke, E Houël


Danish wood preservatives approval system with special focus on assessment of the environmental risks associated with industrial wood preservatives
2001 - IRG/WP 01-50166-01
The following is a description of the procedure used by the Danish Environmental Protection Agency to assess the environmental risks associated with preservatives used in the pressure impregnation of wood. The risk assessment covers issues considered to be of significance for the environment and which are adequately documented so as to allow an assessment. Such issues are persistence and mobility in soils, bioaccumulation and the impact on aquatic and terrestrial organisms. Unless required in special circumstances, the assessment does not apply to birds and mammals as the normal use of preservative treated wood is not expected to involve any noteworthy exposure of these groups. Approval of wood preservatives will be based on a general assessment of the environmental risk associated with the normal use of wood treated with the preservative in a realistic worst case situation. The assessment may address other aspects such as disposal and total life cycle.
J Larsen


Proposed method for out-of-ground contact trials of exterior joinery protection systems
1981 - IRG/WP 2157
Methods for testing the efficacy of preservative treatments for exterior joinery are described using the format of a European Standard. Commercially used treatments applied to jointed test units (L-joints) which are then protected by conventional finishes are exposed to normal outdoor hazards out of ground contact. Assessment is made a) by determining eventual failure through decay and b) by destructive examination of replicate treated and untreated units, after increasing time intervals, rating comparative performance in terms of wood permeability increase and the progress of microbial colonisation.
J K Carey, D F Purslow, J G Savory


Granitgard used as a partial and perimeter barrier in the protection of buildings against subterranean termites
1995 - IRG/WP 95-10114
The graded granite subterranean termite physical barrier, commercially marketed as Granitgard, has a Certificate of National Accreditation issued by the Australian Building Codes Board, and is included in Australian Standards. After several years in developing the specifications and installation techniques for Granitgard, it may be used to protect almost all footing designs. Granitgard can be simply placed around slab penetrations and buildings perimeters to provide a durable, long-life subterranean termite barrier. This paper discusses the development of partial and perimeter applications of Granitgard around buildings, and the advantages of using a termite barrier that removes the need for costly and dangerous chemical retreatments.
D M Ewart, J R J French


Developments in the protection of wood and wood-based products
1980 - IRG/WP 340
Technology is playing an increasingly important role in the field of wood protection. This current review highlights how modern techniques have provided greater insight into the biological and physical processes affecting the durability of wood and wood-based products. Emphasis is also given to developments in preservative testing methodology and to the encouraging changes towards both the correct use of timber and the improvement of Standards and Codes of Practice. A final section, on recent technical developments in wood preservation, considers subjects ranging from an evaluation of new specific biocides to methods of increasing the permeability of refractory timber species.
J M Baker


Evidence supporting the use of termite baiting systems for long-term structural protection
2000 - IRG/WP 00-10377
The efficacy of the Sentricon Colony Elimination System containing Recruit II termite bait (0.5% hexaflumuron) in controlling active subterranean termite infestations has been demonstrated in numerous studies. This baiting system and other termite baiting systems are now widely used, and generally accepted, tools for remedial termite control in North America, Hawaii, and other parts of the world. The role of baiting systems in prevention of termite damages and long-term structural protection, however, is more controversial than their use in remedial control. We discuss three lines of evidence in support of the use of baits for long-term structural protection: (1) successful control of termite populations with baits in remedial studies allows a conceptual leap to preventative efficacy, since baits target colonies and populations and cannot be evaluated directly for prevention in the manner of soil insecticide barriers; (2) field and laboratory studies demonstrate that termite colonies feed on multiple resources and continue to radiate outward from each of those resources in search of additional food, increasing the likelihood of rapid bait discovery; and (3) results of our long-term field studies over the past decade demonstrate that newly invading termites will reuse existing galleries in the soil left by earlier colonies that lead to monitoring stations, were detected in monitoring stations, and were subsequently eliminated without any noticeable evidence of structural infestation or damage.
J K Grace, N-Y Su


The registration of wood preservatives under the Pesticides Act of 1962 in the Netherlands
1976 - IRG/WP 364
J Van der Kolk


Conservation of wooden cultural property
1994 - IRG/WP 94-30038
A survey of the conservation of wooden archtitectual monuments, art objects and archaeological finds is presented. Each of the three areas has typical conservation problems which reqire the use of selected wood preservatives and consolidation agents. Furthermore specific protection and consolidation methods are necessary. A precise damage diagnosis with non-destructive testing methods is the first step in a careful conservation work.
A Unger, W Unger


Termite and decay protection - A superficial barrier field test
1983 - IRG/WP 3257
Samples of Pinus radiata were given a superficial barrier treatment and installed in the ground at two sites for five years to observe termite and fungal attack. The three best treatments of the series were Denso petroleum tape, Koppers hot dip tar enamel, and Arquad 2C/75 alkyl ammonium compound. As new fungicides and insecticides become available they are being added to the test using the same system of treatment and exposure.
R S Johnstone, W D Gardner


Efficacy of anhydrides as wood protection chemicals - II. Performance against soft rot fungi
1998 - IRG/WP 98-30174
Pine sapwood modified with various anhydrides and with butyl isocyanate was tested for its resistance to soft rot decay. Small stakes were exposed for 20 months in unsterile soil in a fungal cellar test. Wood modified with butyl isocyanate performed better than any of the anhydrides tested, with a threshold level of protection (less than 3% weight loss) at 12% weight percent gain (WPG). Stakes acetylated to 15% WPG did not give complete protection against soft rot. Stakes modified with alkenyl succinic anhydride showed increasing resistance to soft rot with WPG up to about 10% WPG, above which no further improvements were evident. Succinic anhydride and phthalic anhydride treated stakes showed little or no noticeable protection.
S C Forster, M D C Hale, G R Williams


Reliability-based service life prediction methodology for assessment of water protection efficiency for coatings on wood
2003 - IRG/WP 03-20268
Assessment of water protection efficiency according to EN 927-5 has been shown to give significant differences in water absorption values for different types of coatings on wood. It is shown that the combination of EN 927-5 and an artificial weathering procedure gives more information regarding expected durability and long-term performance than a single measurement of water absorption on fresh, unweathered wood. A combination of water absorption measurement and artificial weathering could become a useful tool in product development as well as in benchmarking. Together with statistical tools, such as reliability-based service life prediction methodologies for prediction of the service life of coating systems a reduction in testing time may be achieved. The predicted service life can then be the input to integrated life cycle assessment of products for wood protection.
J Ekstedt


Marine borers as wood degraders in Bangladesh and their protection
1996 - IRG/WP 96-10186
Field study on timber piles used in Bangladeshi brackish waters revealed that untreated and pentachlorophenol treated piles drastically degraded by the attack of molluscs and pholads (marine borers). Adequately CCA-C impregnated (30 kg/m³ or 6% W/W dry oxide retention) timber piles can protect the attack of molluscs. It is very difficult to protect pholads which can invade naturally very durable timbers. Adequately preservative treated piles can be protected from pholads by hardening the initial surfaces by noncorrosive metal plates or by cement. Use of only dense and hard timber species would be a solution.
A K Lahiry


Eco-tax - A new threat for wood preservation? The Belgian experience
1993 - IRG/WP 93-50001-32
At the end of January 1993, a bill was put for Belgian Parliament related to the introduction called "Eco-taxes" on a series of products, such as packaging for drinks (especially on PVC-bottles), non-returnable articles (shavers, small cameras), batteries, pesticides for non-agricultural use and paper.
G Van Steertegem, F De Jaeger


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