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Riverbed Construction Technology using Thinned Timbers for Carbon Dioxide Sink in Korea
2010 - IRG/WP 10-50271
The Climatic Change Convention is a big burden in limiting the energy usage like the blood of economy. The certification standard about the carbon storage of timbers after harvesting them is expected to be an important role in setting the goal for future reduction of the green house gas(CO2). The extension of a timber's life span through its preservation is one of technologies for carbon sink. Until now, as the timber is apt to be rotten quickly and eaten by worms, it has lost out to concrete in the construction market. But the fact that it is easily rotten can be interpreted as little burden to the nature environment, then it is again considered as an advantage. Because it returns to the nature after being used, so it doesn't burden to the environment. Therefore, for this reason, the fields of construction and civil engineering must actively utilize many structures using timbers. In Korea, as a part of the river development, it is being developed to store carbon in a timber for a long time, overcoming the problem of timber's easily rotten character, which has been difficult for most nations to find a solution. The principle of the technology is in that a timber in water isn't easily rotten. All rotting fungus that rotten timbers are aerotropism, so the fungus can't live without air. But in water, as the supply of air is blocked, they can't act. Therefore in water, a timber can be preserved not being rotten at least for more than 200 years. If we raise a tree for 50 years, use its timber for another 50 years, and returns it to the nature, the way will not be helpful for our Earth environment. But if we use a timber for 200 years after raising it for 50 years and return to the nature, it will absolutely be very helpful to the Earth. This is the best way to extend the cycle of carbon circulation. In making ecofriendly river, if riverbed using tinned timbers is constructed, the stored carbon volume for harvested timbers can be increased without any limit. In terms of economic advantages, a timber in water doesn't have to be dried, and can be used as a live tree. Another advantage is that it can be used with no preservative treatment. One ton of tinned timbers can construct about 5m3 of riverbed. Our expectation to the tinned timber is very big because it enables to protect the ecosystem in a river and to make aquatic space with rich variety of species. Therefore timber-riverbed is like to manage “A Forest in a River”. Because efficiently utilizing the products out of cultivating a forest can be a way to fostering sound, energetic woods, and an important preparing measure in terms of the formation of 21st Circulating Society, I intend to introduce the technology of timber riverbed.
Dong-heub Lee, Won-Joung Hwang
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
A practical method to evaluate the dimensional stability of wood and wood products
1990 - IRG/WP 2342
This paper presents a new simple method to evaluate wood and wood products for their resistance to swelling and to assess wood preservatives for their ability to dimensionally stabilize treated wood exposed to water. Permeable wood of various dimensions and treated with different preserving chemicals have been measured for swelling in the radial and tangential direction during immersion in liquid water. The results indicate that a simple exponential function describing the dimension of the samples during immersion can be used to evaluate both the water-repellency and anti-swelling effectiveness of wood preserving chemicals. The results can be achieved in reasonable time, and the parameters of the function can be determined by a commercial desk-top computer program.
J P Hösli
Forest products laboratory methodology for monitoring decay in wood exposed above ground
1995 - IRG/WP 95-20074
Research at the Forest Products Laboratory on the durability of wood in service has included a full complement of laboratory and field tests. In this report, we present a review of past and current methods used to evaluate the condition of preservative-treated wood exposed above ground. Current protocols are described for tests on wood packaging, roofing, and dimension lumber.
R C De Groot, T L Highley
Draft Business Plan of CEN/TC 38 - Durability of wood and wood-based products - Introduction
2000 - IRG/WP 00-20207
CEN Technical Committees and Business Planning. The extension of formal business planning to CEN Technical Committees (CEN/TCs) is an important measure which forms part of a major review of business processes (known as 'Optimization'). The aim is to align the CEN work programme with expressed market needs and to ensure the adequate resourcing of projects through their development stages in the CEN/TCs. Your role in the implementation of the Business Planning concept will contribute significantly to the overall effectiveness of European standardization. We express our sincere appreciation and thanks for your time in reviewing this Business Plan.
Volatile borates in the treatment of wood and wood based panel products against subterranean termites
1995 - IRG/WP 95-30094
Blocks of pine solid wood, oriented strand board and plywood were treated with trimethyl borate by vapour treatment. It was meant to obtain either a full impregnation of the specimens or a shell treatment of the outer three millimetres. The efficacy of the treatments against subterranean termites (Reticulitermes lucifugus) was evaluated using an European Standard method.
L Nunes, D J Dickinson, R J Murphy
Inventaire des "déchets" ou produits connexes de la filière bois
1993 - IRG/WP 93-50001-33
Work program of CEN/TC 38 (April 1993). Durability of wood and wood-based products
1993 - IRG/WP 93-20012
The Biocidal Products Directive ( 98/8/EC ) - its consequences for the wood preservation industry
2001 - IRG/WP 01-50166-04
1. The Current Position This European Union Directive is one of the most technically complex pieces of legislation that has been developed by the European Commission (EC). Although the Directive was to have been implemented in the legislation of individual Member States of the EU by May 2000 progress has been slow. A number of Member States have yet to declare the Competent Authority who will handle their legislation. The body text of the Directive cannot stand-alone and is dependent on ancillary regulations and the development of technical guidance for both the Competent Authorities in the Member States and also industry to understand their roles in the whole process for the regulation of biocides and the biocidal products containing them. The process is far from complete in terms of a piece of workable legislation and this leaves not only industry but also the Competent Authorities with significant areas of uncertainty. This is potentially economically and socially damaging to the marketing and use of biocides and biocidal products. Because of this evolutionary process this paper can only be written in general terms as by the time the symposium takes place some significant changes to the position at the time of writing may have occurred. 2. Background The Biocidal Products Directive (98/8/EC), (BPD), is a directive which requires that biocides ( as active substances) are approved for use within the EU and the individual biocidal products containing these active substances are approved for use by the Competent Authority(s) of the Member State(s) in which it is intended to market the product. The product authorisation obtained in the first Member State should be mutually recognised by the other Member States in which application for authorisation to place the product on the market is sought. The Directive has to be seen in the context various other Directives, notably the Plant Protection Directive 91/414/EC). Biocidal products are grouped in the directive into twenty three "product types" and wood preservatives are Product Type 8. The intention of the directive is to harmonise the requirements for the placing of biocidal products and active ingredients on the market throughout the EU. EU wide use of so-called Common Principles are intended to be used to assess the dossiers in order to achieve a common approach and eliminate the current situation where individual Member States apply their own particular national approaches and criteria in the assessment and regulation of products . Annex IIA of the directive identifies the data requirements for the active substance and Annex II B for the biocidal product. There are additional data requirements identified in Annexes IIIA and IIIB for each product type reflecting potential for exposure to man and the environment. 3. Entry onto Annex I Any new active substance will require approval before it or any biocidal products including it can be placed on the market. The dossier to be submitted to the EC will have to include additional data and risk assessments for the product types (as defined in the BPD) in which it will be intended to be used. For those active substances that are accepted as being existing substances on the market before May 2000 (say in wood preservatives) these will be ranked and prioritised. This process is being defined in the so-called: Review Regulations. 4. An environmental directive There is no doubt that this Directive has a high environmental content in terms of the data and the associated risk assessments which are to be prepared. The protocols and the end points for some of these data requirements are still being developed. In general the EC considers that modelling exposure using human and environmental exposure scenarios covering the end use of the product is an acceptable approach . Data are required to enable these scenarios to be modelled and risk assessments made. It is necessary that regulators do not make decisions based on hazard assessment alone in the absence of fully worked out and agreed emission scenarios to define exposure levels which generate a realistic worst case risk assessment. Risk is a function of both hazard and exposure. A lot of work has been done in the development of Technical Notes for Guidance intended to help the regulator and the applicant in the submission and the interpretation of the data. Whilst it may be the case that the human toxicity data requirements still leave questions to be answered it is in the environmental aspects part of the regulatory process where there is still much work to be done. The Directive would seem to rely heavily on the development of Pass / Fail criteria in simulation tests. This is a big subject and of key importance to the risk assessment. 5. Wood preservatives ---- a test case Wood preservation has achieved a certain reputation. On the one hand it is said that a prime reason for the development of the Biocidal Products Directive arose from European problems in the regulation of the marketing and use of dangerous substances, notably wood preservatives. On the other hand because wood preservatives have been regulated by a number of Member States for many years it is believed they are well understood. The EC and the Member States also wanted to be seen to have achieved early success in the implementation of the Directive therefore the decision was taken to start, following failings with the speed of progress of the Plant Protection Products Directive, with a product type they knew all about i.e. wood preservatives. There is no doubt that there is a much greater understanding on the exposure scenarios, both human and environmental, for wood preservatives than many other product types. However, would it not have been better to have tackled some of the other product types where such an understanding is much less well developed? It is regrettable that the EC and Member States did not feel able to accept the results of an EC sponsored study (Haskoning report) on the assessment of risks for all the product types covered under the BPD. The results of this study clearly showed that wood preservatives did not constitute the most significant risk to man or the environment and in fact the risk was significantly greater for other product types. 6. Wood preservatives and the OECD Biocides Programme Another speaker will be covering this subject in more detail. Suffice it to say that because of the perception there was good knowledge about wood preservatives again they were selected as the pilot for an OECD project looking at environmental and human exposure assessment under the OECD Biocides Programme. The findings from two OECD Workshops actually demonstrated there was still much to be learnt about wood preservatives in order to refine the risk assessments to a state where they would be sufficient for the requirements of the BPD. This work is ongoing but it clearly demonstrates the problems that both the regulator and industry will have in the preparation and the assessment of the dossiers for both the active substances and the biocidal products. This is especially the case for other biocidal products that have not been subject to the same kind of regulation that wood preservatives have subjected to in the past. 7. Inorganic and organic biocides With current wood preservation technology there is still a dependence on inorganic chemicals such as copper (in conjunction with other biocides) or with chromium, as well as arsenic and boron for many end use applications. This is very much the case where a long term service life is a key factor in the use of treated wood for that end use. These substances are commodity chemicals and are also covered under the Existing Substances Regulations (EC) 1488/94. There is also work going on revising the Technical Notes for Guidance covering them . This includes a significant addition in the environmental risk assessment area. Efforts are being made to integrate and coordinate the requirements for both the BPD and the Existing Substances Regulations and OSPAR ( OSPAR Convention for the Protection of the Marine Environment of the North-East Atlantic). OSPAR refers to the Oslo Paris Convention. Whilst the BPD seems primarily aimed at the regulation of biocides based on organic chemicals wood preservative products may contain both inorganic and organic components. Indeed there are probably few wood preservative formulations on the market that contain only one active substance. This must have a significant impact on the way the dossiers are prepared for the active substance and the biocidal products and how they are assessed both at the EC and the Member State level. 8. Consequences of the BPD for the wood preservation industry Whilst this paper addresses the consequences for the wood preservation industry per se, it must not be overlooked that there may be implications for the fabricaÈors of articles made from treated timber. Some current wood preservative formulations may over a period of time be withdrawn from the market because the risks and costs of generating the data and the preparation of the dossier make the product economically unviable. The presence of large working volumes of wood preservative solutions at treatment plants requires realistic withdrawal periods to avoid the unnecessary disposal and associated environmental risk of products that have been used satisfactorily for many years. 9. Availability of active substances The structure of the industry has changed dramatically in the past few months and there is no doubt that other changes both within and outside the wood preservation industry itself are yet to happen. The original differentiation between formulator of wood preservatives and active substance suppliers to the wood preservation industry has become blurred. Some of the active substances used in wood preservation are used in other either other biocidal product types or in products regulated under another directive, e.g. Plant Protection Products Directive 91/414/EC. 10. Data protection This continues to be a key issue for industry and some companies may find it strategically or financially necessary not to support an active substance in a particular product type thus leaving that sector without being able to use the active substance. The coming months will start to reveal which active substances are likely to be supported, at least through the notification process. Formulators are therefore in a close dialogue with their suppliers to try to determine their intentions on whether or not they intend to support their active substance. Today's wood preservative formulations are largely multi active substance based. Product costs, efficacy spectra, niche marketing and other considerations have made this process inevitable. New wood preservative formulations take time to research and develop and the continuity of availability of a choice of active substances is of key importance. A lack of adequate return on investment necessary to sustain the development of new products could have a negative impact on innovation and the rate of introduction of new products. It is extremely unlikely that any new active substance will be solely developed for use in wood preservation. This would be an effect contrary to expectations of the EC. The situation with wood preservatives is complicated by the fact that treated wood is a construction product and comes under the scope of the Construction Products Directive (89/106/EEC) (CPD). Products under the scope of the CPD are required to meet certain so-called essential requirements and one of these is durability. Demonstration of compliance involves the extensive suite of CEN wood preservative efficacy tests. Even relatively small changes in formulations may require extensive re-testing under the EN 599 regime in some Member States. 11. Task Forces Companies are encouraged by the EC to enter into Task Forces in order to reduce the burden of testing on animals and also to reduce the number of dossiers to be reviewed for each active substance. Ideally, and understandably, the EC would like one dossier per active substance. Parts of the wood preservation industry have been co-operating in Task Forces and much practical experience has been gained. Even closer co-operation will be required and this will enable companies to pool experience and expertise and manage their financial exposure to potentially high regulatory costs by sharing them amongst a larger number of parties. 12. Financial aspects Industry will have to make some best guesses with respect to its investment programmes for supporting its portfolio of products. Formulators and active substance suppliers are likely to group into Task Forces in order to reduce their costs in terms of data generation and the fees likely to be charged at the EU and the Member State level for the assessment of the dossiers. The compilation of the dossiers requires specialist expertise to assist the industrial applicant(s). This is likely to cost in the order of £100,000 per active substance, not including the costs of generating any data. The Rapporteur State's costs for reviewing the dossier is also expected to be of the same order. Clearly these kinds of costs will impact on innovation. An adequate payback must be available to the company to justify this level of investment. 13. Will mutual recognition work? Member States are required to recognise the authorisation of the biocidal product placed on the market in the first Member State when subsequent applications are made to place the product on the market. This is a fundamental principle of the BPD, although there is concern that Member States continue to have enough flexibility to prevent this happening if there are particular concerns in that Member State. Industry very much hopes this will not be the case and that mutual recognition, a fundamental principle of the BPD, will work in practice. 14. Environmental aspects Biocidal products such as wood preservatives are generally applied in controlled situations and not over large areas. Consequently any emissions can be considered to be from discreet sources, such as treated timber or potentially from timber treatment plants. This is in contrast to plant protection products and some other biocidal products that are usually dispersed over a relatively large area. Because of this a lot of work is required to be done to re evaluate how the environmental aspects of biocidal products such as wood preservatives can be assessed in an objective manner. The criteria that define an emission and how the PEC (Predicted Environmental Concentration) for each environmental compartment is determined are critical. The wood preservation industry, through the EWPM (European Wood Preservative Manufacturers Group), has been working with institutes and other interested parties in a co-operation known as the EFG (Environment Focus Group) to progress the development of appropriate methodology. Data will be required for both primary and secondary exposure to treated timber. The protocols for this work are yet to be agreed. This work is being further progressed in the OECD together with input from CEN TC 38 WG27. This co-operation between the OECD and CEN is extremely significant in that it is, I believe, the first time such a co-operation has taken place in the development of an OECD Guideline. If one considers all of the end uses where treated timber may be found carrying out a risk assessment with few guidelines on how it should be done is a very uncertain process for both industry and the regulator. Reliance on so-called expert opinion may be inadequate. 15. Comparative assessment (the substitution principle) This is a process whereby the health safety and environmental properties of acti_u101 ? substances used in the same product type could be compared and those with the most undesirable properties would not be placed on Annex I. Consequently biocidal products containing them would have to be removed from the market. This process is embodied in the BPD but it was initially considered that it would only be applied in the event of problems arising with active substances or products containing them rather than being used as a screening tool early on in the review process for active substances. This area is still an uncertain one with Member States having different interpretations of this principle. It is unfortunate that the wood preservation industry could be used to test out this concept at a European level. The consequences of this principle could be further losses of active substances available to the wood preservative formulators. 16. Substances of concern The BPD is not only concerned with the active substances that are formulated into the biocidal product but also with so-called "substances of concern". These are defined as any substance, other than the active substance, which has the inherent capacity to cause an adverse effect on humans, animals or the environment and is present or is produced in a biocidal product in sufficient concentration to create such an effect. There are significant implications for the formulator of the biocidal product . The formulator may have to submit an extensive dossier containing toxicological and metabolic as well as ecological data on each of the substances of concern when seeking approval for the biocidal product. There may be classes of compounds that become unavailable to the formulator either because of the risks posed by the co-formulant or because the cost of generating data will be uneconomic. 17. The wood preservation Industry's view on the BPD Industry has supported the development of the BPD since its conception in 1989. It is still supportive it but believes that the degree of complexity is disproportionate to the level of risk when it comes to wood preservatives. After all wood preservatives have been regulated for a long time and in reality there have been few significant health safety and environmental problems associated with them. Industry believes there is no need to determine an absolute understanding about a biocide and its application but rather there is a need to determine the level of understanding that will enable characterisation so that a risk assessment can be made. The wood preservation industry has sought either directly or through representative bodies a pro-active and collaborative approach with the regulators although at times this appears to have encouraged inappropriate demands. The regulators have invariably responded positively to this however they may not always understand the burden in both time and resource in having made wood preservatives the test case. Industry hopes that its efforts to be pro-active will be recognised and will be dealt with equitably when considered before the other product types defined in the Biocidal Products Directive.
Developments in wood preservation processing techniques in New Zealand
1980 - IRG/WP 3143
P Vinden, A J McQuire
Wood preservation in Kenya
2000 - IRG/WP 00-40191
Current research on wood preservation in Kenya is mainly on the development of biological control of wood-destroying termite species, using mycoinsecticides. The major research institutions include the Kenya Agricultural Research Institute (KARI), Kenya Forestry Research Institute (KEFRI), Moi University and the International Centre for Insect Physiology (ICIPE). Training institutions include Forestry Training College, Forest Products Training Institute and Moi University. A number of publications, mostly an biological control of termites, are available and they range from workshop and conference proceedings to theses and journal publications. Wood-destroying termite species include several genera in Macrotermitidae and one drywood termite genus. Wood preservation facilities are available in Kenya, mainly for assorted timber products, sleepers and utility poles. The major preservatives used are CCAs, PCP and Creosote oil. There are still no set standards, specifications and requirements for wood preservatives and little, if any information exists on the marketing aspects of wood preservatives. The yet to be established Industrial Chemicals Act and the recently introduced Environmental Management and Coordination Bill (1999) may be able to handle regulatory, environmental, health and safety aspects of wood preservation in Kenya.
Sustainability Through New Technologies for Enhanced Wood Durability. COST Action E37 – A New Action in the Forestry Domain
2004 - IRG/WP 04-40293
The main overall objective of the action is to concentrate on the contribution of wood durability on the sustainability through the development of systems for quality assurance and perfoamance of modified wood and wood products as alternatives to wood treated with traditional preservatives. By this means it seeks to improve and consequently increase the cost-effective use of sustainably produced European timber, wood-based fibre, and recycled raw materials. The action will seek to optimize methods for testing and characterizing durability performance against physical as well as biological factors. This will exploit relevant selected results from specific aspects of the preceding COST Action E22 on “Environmental optimization of wood protection” and in the EU thematic network for wood modification. It will also exploit specific achievements from COST Action E18 “High performance in wood coating”.
Novel wood modification processes for window and cladding products
2004 - IRG/WP 04-40285
Because of the low natural durability and low dimensional stability of European wood species, the usage of wood for window frames has decreased dramatically during the last decade. In a joint project of several German research institutes and the window industry, following wood modification systems were compared. heat treatment (3 different materials from 2 companies) acetylation (pine sapwood and beech wood acetylated with acetic anhydride) polymerisation (melamine resin treated pine sapwood, Interlace treatment, furfurylation) wax treatment (pine sapwood, which was impregnated with natural resin and waxes) Investigated was the moisture content, dimensional stability, capillary water uptake and the durability. The dimensional stability show a high increase for following materials: heat treated wood, acetylated pine, interlace treated wood and furfurylated wood. The melamine resin treated wood and the wax treated wood show no significant increase in the dimensional stability. The biological durability against different basidiomycetes was tested according to the EN 113. As test fungi, Coniophora puteana, Poria placenta and Coriolus versicolor were used. The results show a very high increase in the durability for most of the treated wood. The wax treated wood shows no significant increase in durability. A novel window frame consists of several functional layers. Different wood properties are demanded for the single layers to achieve optimal window properties. Every modified wood shows a special potential for the use in a functional layer.
A Krause, C Hof, H Militz
Waste management of wood products in life cycle assessment
2000 - IRG/WP 00-50154
Within the framework of the European project LIFE SYS WOOD (contractnr. FAIR CT95-7026) TNO has performed a study on the waste management of wood demolition waste for inclusion in Life Cycle Assessment. In LIFE SYS WOOD one of the main aims was to develop a consistent LCA methodology for wood products. LCA case studies have been performed by partners on wood as raw material, glulam contructions, OSB and plywood roof constructions, window frames, a CCA-treated fence and multi-layer parquet flooring. For the relevant European countries involved contributions to this study of all research partners (EMPA, Imperial College, NTI, Traetek and VTT) have been included, on the composition of the wood waste, on the state of the art of waste management techniques and regulations, and the estimated mix of waste treatment options. The approach in consistently handling final waste management of wood products in LCA and some results are summarised in this paper. For several wood products it has been concluded, that the waste stage has a very significant impact on the LCA results.
P Esser, P Eggels, A Voss
Health and safety aspects of the use of wood preservatives in Sweden
1977 - IRG/WP 396
The Act on products Hazardous to Health and to the Environment (Swedish Code of Statutes SFS 1973:329) came into force on 1st July 1973. The Act cancelled and superseded the Poison Act, the Pesticides Act and the PCB Act from 1962, 1962 and 1971 respectively. Regulations for the implementation of the Act are contained in the Ordinance on Products Hazardous to Health and to the Environment (SFS 1973:334) and also in an Amendment of the Ordinance (SFS 1973:1050). A comprehensive summary of the Act and the Ordinance prepared in common by the Swedish Ministries of Agriculture and Foreign Affairs has been deposited in the IRG/WP Secretariat. Much of the information given below as regards the Act is derived from this booklet.
Treatment of wood-based panel products with volatile borate
1990 - IRG/WP 3616
The paper presents recent developments in the use of volatile borate esters for the preservative treatment of wood based board materials. Several advances on previous reports are discussed. In laboratory studies, treatment times of approximately ten minutes at 20°C on boards at equilibrium moisture content provided full penetration and retentions of 1% wt/wt boric acid. Biological tests have been conducted on a wide variety of boards treated by the vapour boron method. In all cases a retention of 0.7% wt/wt boric acid gave complete protection from decay. These results are considered with regard to parallel studies on solid wood by colleagues at the Forest Research Institute, Rotorua. The advantages of vapour boron treatment for wood based board materials are discussed.
P Turner, R J Murphy, D J Dickinson
Risk reduction from curative treatments, restoration and maintenance of building and individual housing - simple precautions that make the difference
2005 - IRG/WP 05-50224-15
This document explores the potentialities of risk reduction, from activities of remediation in construction, developped at small scale by professionals or individuals on targets like moulds, rots, termites and other wood destroying insects, with products distributed for professional or do-it-yourself purposes. At the first stage, an inventory of the type / interest of products / processes is carried out, with the identification of the sequences, including the fate of wastes and the resulting exposure for the compartments of interest. For health aspects, a crude practical evaluation of the exposure of direct receptors, operators, and indirect ones, inhabitants and the public in the vicinity, to the pathologies and their remediation, seems possible. This exercise aims to provide the users of products with the minimum set of tools and criteria of direct exposure assessment, prior to their use, based on available documentation, regulation and warnings. The best case occurs with the access to material safety data sheets and the corresponding labelling. Per default, they take available products from the shelf (approved for marketing or restricted use, doses, conditions of application), with the support of suppliers and local requirements. Regular training is one way of progress, the obligation of result with procedures adapted to the site of the building and its own exposure, another route of improvement. As works in this field are often non typical, there is still room for the optimisation of individual options, based on experience, to locate the necessary dose and performance at the right place. Description and examples are provided.
Copper leaching from Kemwood ACQ and Embalit CBC treated wood products
2000 - IRG/WP 00-50150
TNO has performed a study on the leaching of copper from Kemwood ACQ and Embalit CBC treated wood products, further referred to as ACQ and CBC. The sawn dry wood has been impregnated using an industrial vacuum-pressure process with ACQ (with or without Ultrawood 4) or with CBC, under supervision of Flexchemie B.V. After treatment samples have been transported and subjected to leaching tests at TNO. The leaching tests applied were a submersion test according to NEN 7345 and shower tests according to a fixed protocol (Havermans et al., 1993). Parallel to each shower tests two or three screening tests for leaching have been performed, according to the existing guideline (BRL 0601, 1999) and according to experimental spray and submersion protocols. The screening should indicate, if the leaching limits of the guideline are likely to be met or not. The results of the screening leaching test have been plotted against the results of the shower tests. It has shown that the existing leaching limit for the "standard" guideline screening test of 0.5 mg copper per ml. is too low and does not indicate if the wood will perform well in the shower test, for both ACQ and CBC treated wood. The experimental spray test has shown to be fairly good as prediction for compliance in the shower test. Furthermore the submersion test according to NEN 7345 has shown promising reductions with a factor 3,7 of copper leaching in ACQ and Ultrawood 4 treated Norway spruce compared to an earlier test with ACQ treated Scots pine. The copper emission in CBC treated Scots pine was a factor 2,5 higher compared to the ACQ-Ultrawood 4 treated Norway spruce.
P Esser, W L D Suitela, H Trompetter
Distinguishing isolates of Aureobasidium on the basis of their ability to utilise lignin breakdown products as a sole carbon source
1996 - IRG/WP 96-10151
Wild isolates of Aureobasidium were obtained by dilution plating from a ca 20 year old painted pine window frame. Four isolates were obtained from the paint/wood interface region and four isolated from regions deep in the wood. The isolates were then used to inoculate liquid cultures containing ferulic acid, a lignin breakdown product, present as the sole carbon source. Ability of the isolates to use ferulate, judged by fungal yield, viable propagule count and absorbance at 280 nm (a measure of the aromatic's final concentration) was dependent on the site of isolation. Isolates from the paint/wood interface were consistently better at utilising ferulate than those isolated from deep in the wood and a possible reason for this is suggested.
M W Schoeman, D J Dickinson
Risk assessment of energetic valorization of treated wood - wooden recycling
1996 - IRG/WP 96-50072
The most useful method for the valorization of wood wastes and wooden wastes is energetic valorization. In France the percentage of wood treated by antisaptain products is around 30%. Currently with the growing regulation, there is a need for cleaner methods and technology to allow sustainable valorization. The preservatives concerned are common organochlorine compounds (NaPCP) less used nowadays in France and another product used at large scale now composed of quaternary ammonium and boron compounds. Results concerning air emissions during the combustion process, chemical analysis of process residues, toxicological evaluation of combustion exhaust gas in rats and ecotoxicological evaluation of residues is presented to assess the risk of recycling processes.
G Deroubaix, P Marchal, G Labat
Pest control products act. An overview of regulation of heavy duty wood preservatives
1995 - IRG/WP 95-50040-30
The regulation of pesticides in Canada is carried out under the authority of the Pest Control Products Act and Regulations. Products which control, prevent, destroy, mitigate, attract or repel a pest are required to undergo a presale assessment for safety, merit and value. This review will determine whether a product, when used according to label directions, can be used both safely and will be effective for controlling pest(s). Four federal government departments, Health and Welfare Canada, Environment Canada and Agriculture Canada, Natural Resources Canada, are involved in making timely and acceptable regulatory decisions on wood preservation products. Presently wood preservative products represent approximately four percent of the active ingredients contained in registered pesticide products and are registered for use areas such as pressure treatment, sapstain control, millwork and remedial applications. Requests for registration of new products are subjected to a rigorous assessment of health effects (both acute and long term) as well as environmental impact. The number and nature of studies requested is largely dependent upon the manner of intended use. There are several ways in which pesticides are regulated. The first time a product is reviewed it could be registered for up to 5 years. At the end of each five year period, pesticide manufacturers will be asked to renew their license for another 5 years. Periodically, new information or concerns come to the attention of regulatory officials. Depending on the nature of this new information, it may be appropriate to conduct a special review of some aspect of a pesticide registration i.e. the effect of use on fresh water ecosystems. In other cases, it will be appropriate to do a complete reassessment or reevaluation of a pesticide because the nature of the possibility of a risk of harm to humans and the environment. Presently there are approximately 20 pesticide active ingredients (of the total 500) being reevaluated. The canadian reevaluation process has been organized into eight (8) steps: 1. Prioritization; 2. Conffrmation of Priority; 3. Announcement; 4. Identify and Assess Risk(s) and Value(s); 5. Discussion of Facts and Regulatory Options; 6. Consultation with Stakeholders; 7. Make Decision and Inform Interested Parties; 8. Implementation of Decision.
The EWPMG proposal for the environmental risk assessment of wood preservatives
2001 - IRG/WP 01-50166-09
This paper reviews the protocol prepared by the European Wood Preservative Manufacturer's Group, which could be used by an applicant for product approval under the Biocidal Products Directive 98/8/EC, to produce a risk assessment for an active substance or product in the Product Type 8 Wood Preservatives, in support of the application. The background and scope of the protocol are reviewed. The principles of environmental risk assessment are reviewed with particular reference to wood preservatives. The protocol is described and an example flowchart is included.
E F Baines
A field method for determining the above-ground resistance of wood and wood products to attack by subterranean termite
1994 - IRG/WP 94-20035
A method for determining the above-ground resistance of wood and wood products to subterranean termites in the field is described. Termites are aggregated in 20-litre steel drums, each containing a highly susceptible timber substrate. At the centre of each drum, specimens of the test material under evaluation are sandwiched, using circular sections of wire mesh, between two layers of the substrate. The drums are connected by plastic piping to infested trees or to other drums which have previously aggregated target species of termites. Preliminary results in the use of this method are presented in a study comparing the resistance of eight untreated timber species and one species treated with a copper-chromium-arsenic (CCA) formulation to Mastotermes darwiniensis Froggatt and Coptotermes acinaciformis (Froggatt) in the Northern Territory of Australia. Advantages of this field method are discussed
J W Creffield
Black Stain of Western red-cedar by Aureobasidium pullulans and its Relationship with Tropolone Depletion
2005 - IRG/WP 05-10564
Western red-cedar is valued for its natural durability conferred by fungicidal tropolone chemicals. However, weathered surfaces of WRC products are still susceptible to ‘black stain’ caused by fungi such as Aureobasidium pullulans. The effect of weathering on the tropolone content of heartwood was characterized and correlated with the ability of this fungal species to colonize the same weathered surfaces. UV plus water spray severely reduced tropolone content but did not lead to increased fungal colonization compared to un-weathered wood. When WRC was treated with UV only, the tropolone content was less affected but the fungal colonization increased significantly. A.pullulans exhibited high tolerance to the tropolone β-thujaplicin in vitro; thus loss in tropolone content may not be required for colonization. In addition to UV resistance from melanization and ability to use lignin breakdown products as a carbon source, resistance to tropolones may confer considerable competitive advantage to A.pullulans growing on WRC exposed to weather. The application of water spray most likely washed away products of lignin photo-degradation, leaving the wood surface void of accessible carbon sources which resulted in decreased colonization.
R Chedgy, R Daniels, P I Morris, C Breuil
Evaluating the resistance of wood-based panel products to fungal attack
1995 - IRG/WP 95-20071
At present there is considerable disagreement among national research institutes within Europe and panel product manufacturers on the most appropriate method of testing and indeed the need for specific biological durability testing. This paper seeks to place before a broader international audience, the issues related to development of a European standard for evaluating the resistance to fungal decay of wood-based panel products. It rehearses the particular issues which need to be addressed. In particular it identifies as problems to be resolved, pre-conditioning of test samples to remove transient leachable/volatile preservative components, choice of weight loss or strength loss as efficacy criteria, and appropriate sampling levels.
R G Lea, R W Berry