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Developments in wood preservation processing techniques in New Zealand
1980 - IRG/WP 3143
P Vinden, A J McQuire
Accelerated ageing of preservatives in treated wood
1988 - IRG/WP 3476
New preservatives are tested in the laboratory and often in field tests before they are used commercially. Some preservatives, however, tested in the laboratory do not show the expected stability when used in service. The differences between laboratory tests and practical use can never be completely eliminated but must be minimized as far as possible by relevant testing methods. Studies of the effect of different accelerated ageing procedures on the chemical degradation and the wood preserving capacity of six different fungicides or combinations thereof have been carried out. Chemicals tested were tributyltinoxide (TBTO), tributyltin naphthenate (TBTN), furmecyclox, benzalkoniumchloride (AAC) + guazatin and pentachlorophenol. The ageing procedures included exposure of test specimens in a wind tunnel (according to EN 73), in an oven at 40°C, 60°C and 70°C, leaching (according to EN 84) and combinations of these procedures. The influence of the different accelerated ageing procedures on the chemical degradation and toxic effect of different fungicides was obvious and, for some procedures and chemicals, comparable with experiences from practice.
M-L Edlund, B Henningsson, B Jensen, C-E Sundman
Evaluation of wood treated with copper-based preservatives for Cu loss during exposure to heat and copper-tolerant Bacillus licheniformis
1999 - IRG/WP 99-20155
Copper-based wood preservatives need to be effective against exposure to all types of microorganisms. Wood treated with six copper-based preservatives was exposed to 121°C and 20 psi pressure for 15 minutes under standard autoclave conditions and the copper-tolerant bacterium, Bacillus licheniformis CC01, for 10 d at 28°C and 150 rpm. Sixteen to 37 percent of the copper was released from the wood during autoclaving, with copper citrate demonstrating the highest percent loss. Forty-four to 82 percent of the copper remaining in the samples following autoclaving was removed during exposure to the bacterium in liquid culture; copper naphthenate in oil and ACQ-D had losses of eighty percent or greater of the remaining copper. The bacterium removed as much or more total copper in 4 of 6 gas-sterilized samples (85-94%) than the cumulative effects of steam-sterilization and the bacterium on treated samples. Copper loss from in-service treated wood compromises the efficacy of copper-based wood preservatives.
D M Crawford, C A Clausen
Fundamentals on steam fixation of chromated wood preservatives
1988 - IRG/WP 3483
Weathering of treated wood directly after impregnation leaches up to 2% of copper-chromate-containing wood preservatives. Almost total fixation of Cr+6 is achieved by steaming the treated wood at 100°C to 120°C, preferably 110°C. To initiate such spontaneous fixation 85°C to 90°C inside the wood are essential, which requires heating times ranging from 20 to 80 min, depending on timber species, retention, required depth of fixation, and steaming conditions. Lower temperatures without steam cause an increased leaching, due to drying effect without promotion of fixation. For softwoods the efficacy of the preservative is not effected; in the case of hardwoods treated with CCA, a certain reduction against softrot fungi was noticed. Both bending and compression strength of pine and spruce remained unchanged. A carefully performed steam fixation will effectively reduce pollution.
R-D Peek, H Willeitner
Less pollution due to technical approaches on accelerated steam fixation of chromated wood preservatives
1988 - IRG/WP 3487
Steaming of freshly treated wood at 100°C to 120°C initiates a spontaneous fixation of copper-chromate-containing wood preservatives. For the performance, a suitable anticorrosive equipment is necessary. Good results can be achieved using a separate steaming equipment which allows a rapid heating of the wood. While warming-up, in the wood some preservative solution extends and can be partly extruded. In addition, minor condensation takes place on the surface of the wood and on the walls of the steaming device. Depending on the velocity of the steam supply, it may contain droplets of the wood preservative used. The heated timber itself evaporates water with no detectable ingredients of the preservative. Altogether steam fixation is a promising method to reduce pollution by wood recently treated with water-borne preservatives and allows its use soon after treatment.
H Willeitner, R-D Peek
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.
Proposal for further work on accelerated ageing
1988 - IRG/WP 2314
Finishes for outdoor timbers
1975 - IRG/WP 378
Management of the wood and additives wastes in the wood processing industries: Problematics and technical answers review
1996 - IRG/WP 96-50073
Management pathways for pure wood subproducts are well known and used; but as soon as additives like preservatives, glues, varnishes or coatings are present within the wood wastes, their disposal or valorization becomes more tricky. The different kinds of mixed wood wastes of the wood processing industries, from the sawmill to the furniture manufacture, are identified herewith and their diversity is examined. These wastes can be classified according to their danger characteristics, taking into account the type of additives, their concentration, their availability for the environment, the physical state of the waste. Different disposal pathways are then considered. Combustion, with the possibility of energetic valorization seems the best answer for a major part of these wastes. But this is only possible if good combustion conditions are defined, so that no harmful products are emitted. Moreover, these conditions must be affordable on the technical and economical point of view. Then, some wastes cannot be burned in such a simple way, and need a larger approach, which is presented in this document.
S Mouras, G Labat, G Deroubaix
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
JWPA method for testing effectiveness of surface coatings with preservatives against decay fungi
1981 - IRG/WP 2164
In 1979 JWPA established a new method for testing effectiveness of surface coatings in accordance with practical use of preservative-treated lumber. Comparing the new testing method with JIS A 9302, a few new trials - size of wood specimen, weathering procedure, and decay-test procedure - are incorporated.
Wood preservation in Poland
2004 - IRG/WP 04-30362
Dynamic growth of market demand for wooden elements and articles, generated in Poland increase of interest in industrial preservation. Today, Poland is a substantial producer and exporter of wood made products. Majority of exported wood - approximately 70% - is scotch pine (Pinus silvestris L.), which, due to its natural durability, requires preservation.
Wood preservatives: Field tests out of ground contact. Brief survey of principles and methodology
1976 - IRG/WP 269
This paper contains the following spots: 1.: The general need for field tests. 2.: Interests and limits of field tests in ground contact. 3.: Various methods in use for out-of-ground contact field tests. 4.: Fungal cellar tests are they an alternative to above-ground decay exposure tests? 5.: Conclusions.
IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water. Progress Report 2: Report of treatment and installation in Australia
1978 - IRG/WP 440
The purpose of this test and the procedures to be followed have been fully set out in documents distributed by the International Research Group on Wood Preservation and numbered IRG/WP/414 and IRG/WP/420. The prescriptions set out in these two documents have been closely followed.
Screening potential preservatives against stain and mould fungi on pine timber in Zimbabwe
1995 - IRG/WP 95-30063
The search for environmentally and toxicologically safer chemicals for use in the timber preservative industry against stain and mould fungi has been intensified during the past few years. Results of field tests with two chemicals previously evaluated in the laboratory are presented. The conventional sodium pentachlorophenate was the more efficacious chemical against stain and mould fungi, providing up 90% control at a concentration of 2.5%. A potential alternative, Stopstain a borate-based chemical, gave results only slightly better than the untreated control timber, at a concentration of 5%. Unless the environmental cost and toxicological hazards of traditional chemicals are highlighted the newer and safer chemicals will be reluctantly accepted by industry as they are regarded as being prohibitively expensive.
A J Masuka
A suggested method to test the toxicity of wood preservatives towards the house longhorn beetle
1977 - IRG/WP 275
This method was developed in the Institute for Wood Technology in Sarajevo, Yugoslavia and is used to get quick information on the toxicity of wood preservatives against house longhorn beetle (Hylotrupes bajulus). The method can be used for superficially treated or deeply impregnated wood blocks, and by using small or normal size test material it can be used as a laboratory or field test, and also for accelerated infestation of test material out of ground contact. The paper is given to the International Research Group on Wood Preservation as a suggested method which could possibly be used as a standard. Only the laboratory test method is described.
Field test evaluation of preservatives and treatment methods for fence posts
1985 - IRG/WP 3347
This work presents the field test results after fifteen years exposure of Eucalyptus saligna fence posts treated with six different preservatives and five treatment methods. All the combinations with oil-borne preservatives presented the best results and among the waterborne preservatives, the fence posts treated by immersion method were with the lowest performance in the field test.
G A C Lopez, E S Lepage
Marine testing of selected waterborne preservatives
1987 - IRG/WP 4137
In 1978 a marine test was established at West Vancouver, B C. to determine the performance of selected waterborne preservatives. The preservatives in test were chromated-copper-arsenate (CCA-C), ammoniacal copper arsenate (ACA), a modified formulation of ACA which contained a higher copper content (modified ACA), ammoniacal copper zinc arsenate (ACZA) and ammoniacal zinc arsenate (AZA). The wood species used for the test was red pine. After eight years in test the CCA is providing excellent performance at all retentions, while the modified ACA is showing significant deterioration only at the lowest level. The ACA is performing quite well although it shows signs of surface deterioration at all retention levels. The performance of the ACZA is rated as unsatisfactory at retentions below 32 kg/m³ while AZA was considered to be unsuitable for use in the marine environment.
J N R Ruddick
Registration and approval of wood preservatives in Australia and New Zealand
2001 - IRG/WP 01-50166-06
Wood preservatives are treated as agricultural chemicals in Australia and, at the time of writing, as pesticides in New Zealand. Antisapstain products are currently considered to be agricultural chemicals in New Zealand while wood preservatives in the future will be considered as hazardous substances under the Hazardous Substances and New Organisms Act when this Act is fully implemented. They are regulated and approved for use by Government Departments under Ministers with responsibilities for agriculture and forestry and the environment: in Australia this is the Department of Agriculture Fisheries and Forestry; in New Zealand it is the Ministry of Agriculture and Forestry and, in the future, the Ministry for the Environment. Specific authorities within these Government instrumentalities control the registration and approvals procedures - the National Registration Authority (NRA) in Australia and, currently, the Pesticides Board in New Zealand. The latter situation is in a transition phase, with the Environment Risk Management Authority (ERMA) New Zealand expected to take over from the Pesticides Board by mid-2001. The NRA and the Pesticides Board require data packages that must include details of the preservative's application, chemistry, manufacture, toxicology, environmental credentials, and efficacy. The NRA administers the Agricultural and Veterinary Chemicals Code, which provides the Authority with the power to evaluate, register for use, and regulate the point of sale of a preservative. The evaluation procedure may involve Environment Australia in focusing on exposure and environmental toxicity data, the Department of Health and Aged Care in assessing toxicity to humans and the National Occupational Health and Safety Commission considering user safety aspects. Efficacy data can be obtained through testing to the Australasian Wood Preservation Committee (AWPC) Protocols. AWPC members may also act as experts in the assessment process and may also be involved in the development of national Standards. Thus, there is a ready conduit from registration and approval of a potential preservative to its incorporation for end use into day-to-day working standards.
Environmental status of wood preservation in the UK
1994 - IRG/WP 94-50018
The environmental status of wood preservatives and treated wood in the UK is summarised. The current legislatory position with respect to approvals, supply, use and waste disposal is considered. The bibliography at the end of this paper contains details of all publications referred to together with other relevant information although this cannot be exhaustive.
Organic solvent preservatives. Essays on the ecotoxicology of new formulations
1991 - IRG/WP 3642
The knowledge on the ecotoxicological profile of wood preservatives become more and more important. The acute toxicity against aquatic organisms was examined for oil-borne preservatives, based on combinations of new fungicides (Tebuconazole, Propiconazole, Dichlofluanid) and insecticides (Permethrin, Cyfluthrin). These tests were conducted with fish, daphnia and algae. In principle the different formulations showed similar effects. The results of active ingredients and solvents confirmed the high sensitiveness of daphnia as test organisms. Criteria for hazards for the environment are presented and discussed.
Influence of different fixation and ageing procedures on the leaching behaviour of copper from selected wood preservatives in laboratory trials
2003 - IRG/WP 03-20264
The paper focuses on the role of different parameters, such as fixation, sample size, wood species, and leaching in internationally standardized ageing procedures for wood preservatives from Europe, Japan and the United States. The leaching protocols used were EN 84, JIS K 1571 and AWPA E11 protocols. The wood species were Scots pine, Sugi and Southern Yellow Pine respectively. Three types of commercially important copper-based wood preservatives were used as model formulations, namely copper/copper-HDO, ammoniacal copper/quat and CCA. The most important factors determining the extent of copper leaching in the different lab trials were the sample size (volume/surface ratio) and the fixation conditions prior to leaching. On the other hand, the wood species and the leaching protocol itself were found to have only minor influence on the copper leaching rate in the test methods included in this study.
J Habicht, D Häntzschel, J Wittenzellner
Loss of preservatives from treated wood during service
1992 - IRG/WP 92-3734
During the 23rd IRG conference in Harrogate the matter of preservative losses from treated wood during service was raised. We were asked to collect information in this field and ask now for help from you. Many tests have been carried out at a laboratory scale to study fixation and leaching from wood treated with different preservatives. Very little, however, is reported on losses of preservatives during service. Since these values are of great relevance regarding environmental impact and the final disposal, reuse or recycling of treated wood, it is of great importance to get as much information as possible on the amount of active ingredients lost during service life. We are convinced there are quite a lot of analytical data and additional information available in many places all over the world. It appears to be rewarding to collect those data and put them together adequately to get an astimate of the losses of the different components based on a broad scale of in service situations. This work will be done as soon as information is available and it is intended to present the results on next IRG meeting.
M-L Edlund, D Rudolph
International collaborative laboratory comparison of two wood preservatives against subterranean termites: Third update and first report
1996 - IRG/WP 96-10174
At the 24th annual meeting of IRG in Orlando, USA, in May 1993 an international subterranean termite laboratory bioassay to compare the various preferred termite protocols used by IRG termitologists was initiated. The author was nominated to co-ordinate this comparative laboratory evaluation of two wood preservatives, copper-chrome-arsenic (CCA) and copper naphthenate (Cu-Na) against the subterranean termites used as test termites in Australia, France, Japan, Thailand, United Kingdom and the Unites States of America. Solutions of these two wood preservatives were prepared and impregnated into Pinus radiata wood blocks to obtain loading of 0.0, 0.5, 1.0, 2.0 and 4.0 kg/m³ respectively. All preservative treatments were carried out at the Division of Forestry and Forest Products in Melbourne. The treated specimens were dispatched to the participating researchers who subjected these specimens to attack by their test termite species, and have now returned the specimens to Melbourne. This paper reports the amount of wood consumed and the mean mass loss (%) on both treated and untreated wood blocks by the termites in the various laboratory bioassays.
J R J French
Testing of wood preservatives against marine borers (Part 1). Method of testing wood preservatives against marine borers (Part 2)
1971 - IRG/WP 37
P C Trussell, C C Walden