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Questionnaire concerning assessment of test data from laboratory and field tests
1992 - IRG/WP 92-2418
During the WG II session in Harrogate, UK it was announced, that possibly a working-session on the assessment of test data and correlation between laboratory and field tests might be organised during next year's meeting in Orlando. For that pupose a questionnaire was prepared. The valuable comments and input of Prof. Thomas Nilsson from Sweden is hereby greatly acknowledged.
A R Valcke


Environmental Emission of Wood Preservatives: Interpretation of Data Relevant to BPD Risk Assessments
2009 - IRG/WP 09-50259
The risk assessments for the use of wood preservatives proposed by the OECD and used under the Biocidal Products Directive (BPD) (98/8/EC) require the derivation of leaching rates for active substances. These rates are to be used as input data in to agreed exposure scenarios. The leaching rates can be derived from laboratory testing and from field testing. The relationship between laboratory and field tests has been studied in order to determine the correlation between the two modes of testing. EN84 tests have been used as a method. However, the determination of environmental leaching rates is beyond the scope of this test and it has been found to over-estimate leaching. The OECD guideline 1 (dipping) test has been designed specifically to determine environmental leaching rates from UC3 wood. This paper compares the leaching fluxes derived from OECD guideline 1 dipping tests to those derived from field tests. This allows a comparison of both the magnitude of flux rates and leaching flux profiles derived from the two tests. The magnitudes of the flux rates require the application of correlation factors in order to get agreement; these factors are presented and found to be of the order 5 – 10. The leaching flux profiles are found to be very different when the flux rates are plotted against time. The laboratory test gives an “exponential” profile, i.e. a profile that decreases quite sharply with time and then levels off. The field test produces profiles that are “sawtooth” patterns with time. This “sawtooth” pattern correlates with rainfall. This is in agreement with, and confirms, data previously presented (Baines, 2008). In the present study, however, an alternative method of data analysis is explored. If the field data is normalised according to the amount of rain falling then it is found that the laboratory and field tests produce very similar leaching profiles. Thus, the contrast previously discussed is shown to be an artefact of the method of analysing the data obtained from field tests. This is due to the inherent variability of weather patterns with time that cannot be replicated in the laboratory. If annual average rainfall figures are used, the risk assessments at differing time points can be carried out as assessments at average rainfall amounts. This alternative method of data analysis according to rainfall rather than time suggests a method of analysing the models for OECD risk assessment that can increase their utility.
D G Cantrell


Programme section 2, Test methodology and assessment
1997 - IRG/WP 97-20126
IRG Secretariat


Quantitative assessment of the condition of field specimens
1981 - IRG/WP 2154
Suggestions for a discussion on the desirability of an extension to the existing procedure of assessment of the condition of field specimens by adding more objective, reproducible methods in order to obtain earlier and more specific information than at present on the effect of biological attack on strength and other properties of the specimens as well as the time aspect.
H Friis-Hansen


On site test for indicative determination of leaching of components of preservatives from treated timber. Part 2: New data on CCA-C, CC and CCB treated timber
1994 - IRG/WP 94-50025
The 'on site test' was published at the IRG meeting in Cannes in February 1993 (IRG/WP 93-50001/12). Since this publication many on site tests were performed parallel to so-called shower tests. The correlation between the test results of the on site tests and the shower test has been established more clearly. For chromium the correlation between both tests is indistinctive of preservative formulation. For copper the correlation differs for CCA on one side and CC's and CCB's on the other side. In some cases the on site test does not correcty predict shower test results. The reasons for this phenomenon are discussed. It can be concluded that the on site test is a roughly indicative test for assessing the leaching of components of preservatives from treated timber. The correlation figures, however, are formulation dependent.
W J Homan


Assessment of losses of wood preservatives from treated wood by leaching into the environment
1993 - IRG/WP 93-50001-13
Wood preservative chemicals may be lost from treated timber by leaching into water or soil. The degree to which this might occur and its effect on the environment is difficult to assess quantitatively due to the absence of appropriate test methods. This paper describes work to assess test methodology capable of allowing the rates of loss of wood preservative from treated timber to be quantified. The possibility of adapting simple laboratory equipment to monitor preservative losses from treated wood has been investigated. Losses due to leaching from selected faces of treated wood blocks when immersed in water have been monitored, using disodium octaborate as a model water-soluble preservative. The investigation has demonstrated the importance of distinguishing between transverse, radial and tangential surfaces when considering potential losses and the subsequent likely environmental impact of treated timber in service.
R J Orsler, G E Holland


Quantitative assessment of field specimens. A proposal for discussion
1980 - IRG/WP 2143
H Friis-Hansen


Programme section 2, Test methodology and assessment
1996 - IRG/WP 96-20094
IRG Secretariat


Environmental risk assessment of preservative treated wood
1998 - IRG/WP 98-50101-19
This paper reviews the status of the environmental risk assessment of preservative treated wood and confirms the distinction between the risks presented by wood preservatives and preservative treated wood. The paper proposes a tiered approach to risk assessment and discusses the rationale. Flowcharts are presented which summarise the tiered approach to risk assessment, show the tests required, and show how the results can be used to make an environmental risk assessment of preservative treated wood. The need to generate data specifically for risk assessments, particularly PEC and PNEC values, is recognised. Test methods in existing Standards (EN 84, EN1250-2) are shown to be unsuitable to produce data which can be used in risk assessments. Realistic test methods are proposed using commodity-sized treated wood exposed to simulated in-service situations. A test method to generate risk assessment data for wood in ground contact and wood above ground is described. The results show that boron is adsorbed by soil, and that leaching of boron from treated wood in ground contact, even after 5 days exposed to severe rainfall conditions, is less than 10% of the boron in the wood before exposure.
E F Baines, S J Davis


Risk assessment and the approval of wood preservatives in the United Kingdom
1995 - IRG/WP 95-50040-23
An approval system operates in the United Kingdom (UK) for the regulation of wood preservatives. The regulatory authority uses a risk assessment approach to evaluate how far the potential for harm to people and the environment from wood preservatives is likely to be realised in practise, and hence the controls required for products to be, used safely. The evaluation for approval purposes also takes into account the effectiveness of wood preservatives. A tiered approach is adopted to data requirements, and likely exposures are considered under the proposed conditions of use so that testing is minimised and controls are commensurate with risk.
R M Turner


Programme Section 2 Test methodology and assessment
1999 - IRG/WP 99-20180
IRG Secretariat


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.
D Aston


Data requirements for wood preservatives in the EU Biocides Directive
2001 - IRG/WP 01-50166-08
Directive 98/8/EC of the European Parliament and of the Council concerning the placing of biocidal products (the Biocidal Products Directive, BPD) lays down the requirements on data needed for authorisation of a biocidal product and approval of its active substance(s). The dossier must contain data needed for the proper risk assessment of the biocidal product. A detailed technical guidance document on data requirements for biocides has been produced to ensure the harmonised decision making according to the BPD. The purpose of the guidance is to give detailed testing strategies e.g. for toxicology, ecotoxicology and efficacy of different biocidal products and active substances, including wood preservatives. The data requirements for biocides are divided in two parts: the common core data set lists the studies which are always required, and the additional data set lists the studies which may be required in certain cases e.g. on basis of the results of the tests in the common core data set, and proposed uses and the potential exposure for a biocidal product. The common core data set contains a very comprehensive list of toxicological studies and, therefore, their additional data set is very limited. Instead, for ecotoxicological studies the common core data set is very limited, but the additional data set is very broad. Therefore, the guidance document on data requirement lists those additional ecotoxicological studies that are usually always required for certain biocidal product types - also for wood preservatives - in the application for approval. Waiving for some toxicological studies may be needed to minimise the need for animal testing and to reduce the costs of testing. The technical guidance document for data requirements gives some guidance on such a possibility on exemptions on the data requirements. The need for additional ecotoxicological testing depends on the product type and potential exposure for a product. In addition, the environmental risk found as a result from common core data set is the basic criterion when deciding testing strategy and the need for the additional ecotoxicological testing on e.g. adsorption, degradation and bioconcentration. Issues important for wood preservatives are data required on efficacy and on leaching from treated wood.
H Braunschweiler


Correlation between different international standard assessment procedures with termites. Part 1: Field exposure
1983 - IRG/WP 1198
Ramin treated with copper-chrome-arsenic (CCA), pentachlorophenate and lindane, each at three retentions, and three other untreated timbers were assessed in the field against Coptotermes lacteus and Nasutitermes exitiosus. Replicate specimens were exposed around five mounds of each termite species over a period of five years in south-eastern Australia. The field results provided the basis for judgement of corresponding laboratory trials conducted accordingly to the standard procedures of Europe, U.S.A. and Australia. In the field none of the wood preservative treatments with-stood termite attack for the full period of five years, not even CCA at the highest retention of 2.3 kg/m³. Merbau and Jarrah were the most resistant timbers but there was noticeable variation between trees.
M Lenz, C D Howick, N Tamblyn, J W Creffield, M Westcott


An in-ground natural durability field test of Australian timbers and exotic reference species. Part 5: Extensive data from a site where both decay and termites are active. Results from a full-replicated set of heartwood specimens from each of ten myrtaceous hardwoods after 18, 19 and 20 years' exposure - A discussion paper
1988 - IRG/WP 2324
Extensive data are presented on the decay situation, the termite situation and the decay-termite associations; all gathered from a fully-replicated set of heartwood specimens of 10 hardwood timbers after 18, 19 and 20 years' exposure in the ground at a single test site, i.e. a semi-arid steppe site. Sixteen tables are presented in addition to the one table providing the rating data; the latter representation of specimen condition being essentially all the data normally being recorded from field tests, whether these be of natural durability or preservative treated specimens. The authors give this "extra" data to show the type of information obtainable as a result of applying both mycological and entomological expertise to field assessments. Instead of discussing these results. the authors wish to generate some discussion by asking questions such as - is some of all of this information of value? - What additional/alternative information would interested scientists wish to see with respect to the most durable timbers in a test such as that examined in this report?
J D Thornton, G C Johnson, J W Creffield


The mathematical study of test plot data
1987 - IRG/WP 2282
It has long been desirable to have a mathematical expression, which, by the insertion of statistically derived constants, would describe the behavior of test specimens in service. The philosophy of such expressions is briefly discussed, and the history of the concept is outlined. The modern approach to the problem dates from the graphical presentation of dosage-response and deterioration curves by Colley (1970). In 1972 Hartford devised the "Performance Index" giving a numerical parameter which could give statistically valid comparisons between preservatives in a given installation. A more potent tool is the "log-probability" method, which is now under consideration by AWPA P-6 as a standard. If "log score" is converted to probits x the relationship: x = a + b ln t + c ln R holds well for penta and creosote test specimens at log scores above 30, and tends to give conservative estimates of performance when early results are evaluated. With CCA, this is not true. Recent availability of 19-20 year test results on CCA stake and panel tests (Leach 1986) has permitted the evaluation of "modified probits" as the x in the above equation. Preliminary work shows promise: the CCA results are improved and low log scores can be used. Preliminary data are available on various CCA formulations and stake vs. panel tests.
W H Hartford


Field stake test assessment with the Pilodyn
1980 - IRG/WP 2136
The Pilodyn, which was originally developed to estimate the degree of soft rot in wooden poles, was thought to have potential for giving a quantitative measure of the extent or depth of decay in field test stakes. In the present work a 2-joule Pilodyn with 2.0-mm diameter pin was used in an attempt to limit depth of pin penetration (to 10-15 mm) without reducing scale sensitivity. The results show that this instrument has the potential for evaluating the degree of decay, particularly its depth, in preservative-treated test stakes exposed in "graveyard" test plots. Its major value could be in eliminating observer bias in assessing decay and in quantification of strenght loss. Its greatest application would be in the accurate detection of the depth of superficial decay, particularly in its early stages, and its further progress into test stakes.
M E Hedley, R W Naish


Some data on the activity of alternative fungicides for wood preservation
1985 - IRG/WP 3333
Data from laboratory tests against basidiomycete fungi are presented for 9 alternative fungicides in organic solvent formulations and also in water for one product. Results are compared with data for reference preservatives, tributyltin oxide, copper and zinc naphthenates and pentachlorophenol. Of special interest is the apparently better than additive effect of mixing tributyltin naphthenate and Xyligen B, and the promising performance of Armoblen 480, a novel organic solvent formulation of n-alkyl coco-derived quaternary ammonium compounds.
A F Bravery, J K Carey


Ecotoxicological behaviour of leachates from superficially treated timber as an approach for a test strategy of environmental risk assessment in wood preservation
1998 - IRG/WP 98-50101-09
At present for wood preservatives, which in Germany are subject to the quality mark of the RAL-Gütegemeinschaft Holzschutzmittel, health and safety as well as environmental aspects are evaluated by official authorities, as BgVV (Federal Institute for Consumer Health Protection and Veterinary Medicine) and the UBA (Federal Environmental Agency). From the environmental point of view to day there are additional requirements concerning the environmental behaviour of RAL-preservatives for timber used in hazard class 3. Information on the ecotoxicity of preservatives and ingredients as well as on the effect of losses from treated timber is requested in general. There is a lack of generally approved and harmonized test procedures in this field of wood preservation assessment. Therefore, a first test model was developed in accordance with the German federal environmental agency. This test procedure follows existing standards on efficacy of wood preservatives such as EN 84 and ecotoxicological testing of chemicals. Otherwise, it takes into account practical aspects of the application of wood preservatives. Ecotoxicological studies using fish, daphnids, green algae and luminescent bacteria as bioindicators were conducted with a range of formulations based on modern biocides. The ecotoxicity of leachates from treated timber is compared with the acute ecotoxicity of the formulations themselves. It becomes obvious, that a clear differentiation must be made between the effects of the formulations and the timber treated with them. In all trophic stages tested, it was shown, that enormous safety factors are existing for properly treated timber. It is possible to use the described test model for an environmental assessment with regard to the European Biocidal Products Directive. If ecotoxicological studies of a wood preservative are in accordance with the designed test model, additional ecotoxicological tests on the product or environmentally relevant components of it can be avoided or justifiably confined to a minimum.
H W Wegen, U J Lucks


Assessment of treated wood leachates genotoxicity with a bacterial test
1997 - IRG/WP 97-50089
Genotoxicity is known as the damage caused by environmental stressors (biological, chemical and physical) on the genetic material of an organism. This toxicological effect can be assessed by a lot of biological assays and especially by bacterial tests. These tests are frequently performed on environmental samples or on pures substances and are in that case, strongly correlated to the carcinogenic effect obtained on mammals. A leachate procedure (EN 1250-2) was applied to treated wood (Pinus sylvestris, EN 113 type) in order to simulate and predict the loss of active ingredients through percolation or lixiviation processes. The genotoxicity of the leachates was evaluated with a bacterial mutagenecity test performed on Vibrio fisheri dark mutant and consisted in measuring the light emission of the revertant organisms. Three types of formulations were used for the wood impregnation: a Copper Chromium Arsenic (CCA) water based formulation, an organic and a creosote type formulation. Genotoxicity of the leachates is presented and a correlation between the presence of direct or indirect mutagenic compounds in water and the biological response is then approached.
P Marchal, C Martin


Subterranean termite attack potential in field test sites: assessment methods and field characterization
2003 - IRG/WP 03-10472
To assess subterranean termite attack potential in the field and seasonal variations, trials were set up in each of two managed silvicultural plantations, of Eucalyptus globulus and Pinus pinaster, respectively. Termite occupancy in lying dead wood was evaluated by an adaptation of the line-intersection method, and attack potential in soil was assessed by a system of stakes inserted into the ground, combined with baits. Occupancy in fallen dead wood was assessed over one year, demonstrating that there were seasonal changes in foraging activity. Baits and stakes were assessed at three month intervals, providing a corresponding measure of the intensity of the foraging activity under ground. The usefulness of this dual characterization of field sites is discussed.
T Nobre, L Nunes, L Brinca, D E Bignell


Soil termiticides: A review of efficacy data from field tests
1987 - IRG/WP 1323
This paper reports efficacy data from the field evaluation of various soil termiticides by the U.S. Department of Agriculture, Forest Service, Gulfport, Mississippi. These chemicals, which include a number of chlorinated hydrocarbon, organophosphate, pyrethroid, and carbamate insecticides in a range of concentrations, have been in long-term tests at seven field sites. Data are reported for the ground-board method and/or the concrete slab method of evaluating the effectiveness of these chemicals as termiticides.
J K Mauldin, S C Jones, R H Beal


The ecotoxicology assessment of wood preservatives and their active ingredients by means of germination tests using cress - A critical consideration
1999 - IRG/WP 99-50125
With putting the Biocidal Products Directive 98/08/EC (BPD) in place an environmental risk assessment for wood preservatives and impregnated timber is requested. To assess possible risks, suitable test methods are required, which reveal the ecotoxicological profile including environmental fate and behaviour of treated commodities. Germination and growth tests could contribute to the determination of ecotoxicological effects on plant seeds and their embryos. Investigations were carried out in order to determine the germination and the growth behaviour of cress with the aim, to investigate the possibilities and limitations of these tests. The results show that the cress germination test is very sensitive as a rule. A prevention of the germination as such does not indicate a possible toxicity of the formulation investigated. The assessment of the germination processes as the only criterion is not a sufficient measure for the ecotoxicological profile of wood preservatives and impregnated timber. Germination tests, however, can supply a first indication concerning a possible effect on the environment. In connection with the other methods, it is possible to receive supplementary information in a very short time.
P Jüngel, A O Rapp, E Melcher


Methods for the assessment of wood preservative movement in soil
1995 - IRG/WP 95-50040-08
This paper presents preliminary results from a series of experiments constructed to provide laboratory data for the evaluation of the leaching of wood preservatives into and through soil. The experiments included: i) measurement of the adsorption of preservatives by soil; ii) determination of the concentration gradient of preservatives in soil following percolation of preservative solution through soil; iii) determination of the changes in concentration gradient by subsequent leaching of contaminated soil with water. From an assessment of these laboratory procedures, based upon their practicalness and the results obtained, it was concluded that this range of tests could provide the necessary data to allow a rational appraisal of the potential of a wood preservative to contaminate soil. However, the experimental methodology needs to be examined further using a greater range of soil types, wood preservatives and water sources in order to establish the general acceptability of the approach and to allow standard procedures to be developed.
G E Holland, R J Orsler


Performance of water-borne pressure treated fence posts - A practical application of the new Canadian field test data base
1988 - IRG/WP 2305
50 years of test plot data acquisition have been recently set up as a computerized database. The new database which contains information on the service life of a great number of non durable Eastern Canadian wood species treated with various preservatives and many application processes is presented. As an example for its use, a summary of the performance of fence posts treated with waterborne preservatives is presented.
E E Doyle, R Dubois, J P Hösli


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