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A comparison of soft rot, white rot and brown rot in CCA, CCP, CCF, CCB, TCMTB and benzalkonium chloride treated Pinus radiata IUFRO stakes, after 9-15 years exposure at five test sites in New Zealand
1991 - IRG/WP 1485
The aim of this study was to determine if decay type varies significantly between five field trial test sites of different soil type, aspect and climate in 9-15 year old, replicate CCA, CCF, CCP. CCB, TCMTB and AAC treated IUFRO stakes. A visual on-site assessment of decay type on every test stake was made and observations confirmed by microscopical examination. Regression analyses were used to determine significant differences of percentage frequency of occurrence of each rot type between sites and preservatives. Large differences in percentage frequency of occurrence of rot type were evident between sites. One site was dominated by brown rot (85%) and two were dominated by soft rot (99 and 91%). The fourth site had intermediate proportions of brown rot (40%) and soft rot (71%) but had the second highest occurrence of white rot (32%) (highest = 37%; lowest = 11%). The fifth site was distinct in that a large proportion of stakes (69%) had both well established brown rot and soft rot. Stakes at the other four sites tended to have only one rot type. Some highly significant preservative effects were also found. Possible causes of these differences are discussed in terms of inter-site soil type, climate and other differences.
R N Wakeling
Ultra-structural observations on the degradation of wood surfaces during weathering
1987 - IRG/WP 2280
Radiata pine (Pinus radiata D. Don) sapwood was converted into blocks with a transverse face about 5 mm square and measuring 8 mm longitudinally. Transverse (T.S.), Radial (R.L.S.) and Tangential (T.L.S.) surfaces were prepared and specimens exposed to the weather inclined at 45° facing equatorially for periods of between 20-60 days. After 30 days exposure erosion of the middle lamella was observed followed after 40 days exposure by extensive separation of individual fibres at the interface of the middle lamella and secondary wall. Degradation of the S2 layer of the cell wall revealed corrugations orientated parallel to the fibre axis suggesting preferential removal of cell wall components. Further degradation proceeded by progressive delamination and checking of the S2 and erosion of the S3 cell wall layer. In addition to the above changes preferential degradation of the rays was observed in radial (R.L.S.) and tangential (T.L.S.) longitudinal surfaces.
P D Evans, S Thein
Co-operative research project on L-joint testing. Sampling after 8 months exposure
1983 - IRG/WP 2208
It was anticipated in Document No IRG/WP/2192 that exposure of L-joints by the European co-operators would take place on 1 April 1983. Where L-joints were exposed at this time, sampling after 8 months exposure is due on 1 December 1983. The present document draws attention to relevant previous documents which describe the sampling methods to be adopted. It also provides Tables for recording the results.
J K Carey, A F Bravery
In-ground performance of two formulations of chlorothalonil after five years of exposure at three test sites in Australia
1996 - IRG/WP 96-30101
Sapwood specimens of Pinus radiata D. Don and Eucalyptus regnans F. Muell. were each treated to three retentions of each of two preservative formulations (chlorothalonil in oil; chlorothalonil plus chlorpyrifos in oil) and installed in-ground at three field test sites in Australia. Specimens were treated with each formulation to achieve 3.2, 6.4 and 12.8 kg/m³ of chlorothalonil a.i. and 3.2 + 0.2, 6.4 + 0.4 and 12.8 + 0.8 kg/m³ of chlorothalonil plus chlorpyrifos a.i. For comparison, specimens of each timber species, treated to a commercial in-ground retention of a copper-chromium-arsenic (CCA) formulation, were also installed. Treated specimens (including controls) have been rated for their condition annually for attack by subterranean termites and fungal decay using a scale ranging from 4 (sound) down to 0 (failed). After five years of exposure, mean termite and decay scores for replicate test specimens at each site reveal that the performance of all three retentions of each formulation, particularly the two highest retentions, is comparable to CCA.
J W Creffield, T L Woods, N Chew
Surveillance médicale des personnels exposés aux produits de préservation du bois
1990 - IRG/WP 3588
Performance of untreated French Guianan piling in marine exposure
1992 - IRG/WP 92-4173
Round piling of seven French Guianan species, greenheart, and preservativ-treated Southern Pine were installed as fender piling in Key West, FL. After 12½ years, none of the tropical hardwoods performed as well as dual-treated Southern Pine. Of the hardwoods, kouata patou and maho noir were the most resistant to decay and marine borers.
B R Johnson
Depletion of wood preservatives after four years' marine exposure in Mt. Maunganui harbour, NZ
1994 - IRG/WP 94-50036
This paper reports on chemical analysis of marine test samples exposed in Mt. Maunganui harbour, New Zealand from 1977 to 1981. Depletion data for a Class II CCA, a CCA-A formulation, acid copper chromate and ammoniacal copper arsenate are presented. The results suggest differences in the rate of loss of individual preservative components among the four formulations and redistribution of individual preservative components within the wood.
K J Archer, A F Preston, C M Chittenden, D R Page
Exposure trial at tropical marine sites of pyrethroid/creosote mixtures as wood preservatives: Preliminary results
1989 - IRG/WP 4155
Pinus sylvestris sapwood blocks measuring 25 x 25 x 200 mm³, impregnated using a Lowry or Rüping pressure treatment cycle with solutions of permethrin, cypermethrin or deltamethrin in BS144 creosote, have been exposed at marine sites in Australia, Papua New Guinea, the U.K. and Singapore. The effectiveness of these solutions in preventing marine borer attack is being compared with the efficacy of creosote alone, creosote/CCA double treatment, pyrethroids alone and no treatment. Blocks at the tropical sites have been installed in the intertidal zone in areas where the crustacean borer, Sphaeroma is active. Teredinids (shipworms) of several species are very numerous at these sites and the bivalve borer, Martesia, is present. Limnona colonies were found in untreated blocks at the sites in Papua New Guinea and Australia. The results of inspections after exposure periods of up to 26 months at the tropical sites are summarised in this report. Untreated sample blocks failed rapidly to borers, particularly teredinids. Pyrethroids alone reduced the level of crustacean borer attack and to a lesser extent, teredinid attack. All blocks treated with creosote-containing solutions have so far not been attacked by borers or degraded significantly by micro-organisms. Soft-rot and bacterial degradation occurred in untreated blocks and blocks treated with pyrethroids alone. Settlement by barnacles and serpulid worms appears to be inhibited by the creosote/CCA double treatment, but there is no evidence of long-term inhibition of barnacle or serpulid settlement by pyrethroid-containing solutions, whether with creosote or without. Samples at the site in the UK are exposed to teredinid attack. No inspections have yet been carried out at this site.
S M Cragg
Vertical distribution of fouling and wood-boring organisms in the Trondheimsfjord (Western Norway)
1981 - IRG/WP 467
Results of a detailed study on the vertical distribution of fouling and wood-boring organisms of Trondheimsfjord at an interval of 3 m from intertidal level to a depth of 30 m, has been presented, based on data collected from two series of panels, exposed from 15 March 1977 to 15 July 1977 (Series I) and from 22 July 1977 to 13 March 1978 (Series II). The intensity of fouling generally decreased with increasing depth. Quantitatively, fouling was heavy on panels of Series I more than on Series II, although species-wise it was more heterogenous on panels of Series II. The bulk of the fouling was constituted by Balanus crenatus, Laomedia sp., Mytilus sp., Modiolus sp. and Hiatella arctica. Incidence of borers and the resultant destruction of timber were heavier on panels of Series II than on those of Series I. The influence of the period of exposure on the above pattern of infestation by foulers and borers has been discussed. Psiloteredo megotara concentrated at the upper levels up to a depth of 15 m, with more settlement between 3 m to 9 m depth. Although Xylophaga dorsalis was present on panels from 3 m to 30 m depth, their intensity abruptly changed from 9 m onwards and continued to increase with increasing depth, with a maximum number near the mud level at 30 m. Attack of Limnoria lignorum also was heavy at the mud level. On the same panel, while Psiloteredo megotara preferred to settle in more numbers on the lower surface, Xylophaga dorsalis did so on the upper silted surface. The importance of such selective vertical incidence of different borers and their co-operation in the destructive activity have been stressed from the point of wood destruction in the Tronheimsfjord. The rate of growth of Balanus crenatus, Laomedia sp., Psiloteredo megotara, Xylophaga dorsalis, and Xylophaga praestans in relation to depth has been presented. For Balanus crenatus rate of growth decreased with increasing depth, while for Laomedia the same increas with depth up to 12 m and declined thereafter. In accordance with its depth preference, Psiloteredo megotara registered faster growth between 3 to 15 m depth. In the case of Xylophaga dorsalis, the size of the shell valve and burrow increased with increasing depth up to 24 to 27 m and then showed a slight decline at 30 m. Factors influencing the growth-rate at different levels have been discussed. The results on the vertical zonation and rate of growth of the wood-infesting organisms encountered, have been compared with relevant literature published earlier.
L N Santhakumaran
Soil-bed studies (Part 3): A cause of failure of multisalt preservatives following soil-bed exposure
1983 - IRG/WP 3261
P Vinden, J F Levy, D J Dickinson
Protecting wooden structures
1980 - IRG/WP 392
Chromium-containing chemicals that effectively retard weathering of wood improve performance of subsequently applied finishes. Current work is focusing on the performance of wood-derived products (plywood, hardboard, fiberboard, particle board) after surface treatment with inorganic chemicals. The overall objective of the continuing research is to investigate new environmentally safe procedures to stabilize wood surfaces and to improve performance of applied finishes.
W C Feist
Use of the Pilodyn to assess deterioration of treated aspen waferboard after 30 months of outdoor exposure
1986 - IRG/WP 2254
Samples of preservative treated aspen waferboard exposed outdoors for 30 mo. were compared using pin penetrations of the 6 Joule Pilodyn. These results correlated well with rankings of treatment performance based on more laborious standard mechanical tests, and demonstrate the potential for use of the Pilodyn as a tool to evaluate wood composites in test exposures with minimal destruction.
E L Schmidt, M G Dietz
Evaluation of Barrier Wrap Systems after 71 Months of Exposure
2013 - IRG/WP 13-40631
A 71 month study of the performance of booted samples in ground contact was conducted in AWPA hazard zone 4. Data indicated that excellent performance of wrapped systems, even over untreated wood, could be obtained. Instances of decay colonization or termite attack could all be attributed to some breaking of the integrity of the barrier system. Good performance for treatment below ground contact threshold was demonstrated.
H M Barnes, M G Sanders, G B Lindsey, C McIntyre
Corrosion of fasteners in heat-treated wood – progress report after two years’ exposure outdoors
2005 - IRG/WP 05-40296
The corrosion of common fastener materials now in use - mild steel, zinc-coated steel, aluminium and Sanbond Z-coated steel – has been evaluated after two years’ exposure outdoors in untreated and heat-treated spruce (Picea abies) respectively. Spruce from South-western Sweden was used. The heat-treatment was carried out in Finland according to the ThermoWood process at a maximum temperature of 220 °C for five hours. The results so far show that the corrosion of fasteners in heat-treated wood according to the particular specification is more severe than in untreated wood. Mild steel and zinc-coated steel has been most susceptible. Stainless steel is hardly attacked at all.
J Jermer, B-L Andersson
An in-ground natural durability field test of Australian timbers and exotic reference species. Part 2: Progress report after approximately 13 years' exposure
1983 - IRG/WP 1189
The condition of heartwood specimens of Australian and exotic timber species after approximately 13 years' in-ground exposure is given. Four of the 5 test sites have a termite hazard in addition to the hazard from a range of decay fungi. Values for specimen life are given only where all replicates of a timber species have become unserviceable. Results give evidence leading to doubt about the accuracy of the tentative durability ratings previously ascribed to at least some of the species under test.
J D Thornton, G C Johnson, I W Saunders
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
Short term preconditioning of preservative-treated wood in soil contact in relation to performance in field trials
2000 - IRG/WP 00-20185
The effect of pre-exposure to primary colonising micro-organisms on preservative-treated wood, prior to a basidiomycete decay test, was determined by preconditioning in two soil types. Scots pine EN 113 blocks treated with 3 model systems (a triazole, a copper quaternary compound and a copper boron triazole) were leached according to EN 84 and subjected to 6 weeks and 8 weeks burial in either John Innes no. 2 (a loam-based horticultural compost) or soil from the Simlångsdalen field site in Sweden. The samples were then tested according to the method described in EN 113. Selective isolations were also performed after soil exposure and compared with those from a longer term field trial. Preconditioning lowered the effectiveness of the 2 copper containing preservatives. Some effect of soil pre-exposure could be noted with the triazole but this was limited. The fungal isolations from preconditioned EN 113 blocks and field exposed stakes were a similar mixture of soft rot and mould fungi. Bacteria were commonly isolated from the preconditioned wood. The role of these micro-organisms in the modification of the preservatives is currently being investigated.
S Molnar, D J Dickinson
Exposure monitoring of creosote vapors
1989 - IRG/WP 3511
Creosote oils contain hundreds of compounds. During impregnation and handling of treated wood the main component in the vapors released in air is naphthalene. Other main components are alkyl naphthalenes, indene, phenol and its methyl derivatives, benzothiophene, diphenyl, acenaphthalene and fluorene. In the measurement of creosote vapors, naphthalene can be used as an indicator agent. One of the major urinary metabolites of naphthalene is 1-naphthol. To explore the relation between naphthalene concentration in the air and 1-naphthol in the urine of exposed workers we monitored air concentrations and collected urine samples from six men over a working week. 1-Naphthol concentrations in urine samples were analyzed by GC as a pentafluorobenzylbromide derivative. The average concentration of 1-naphthol in the Monday morning samples was 0.1 mg/l, in the Monday afternoon 3.1 mg/l, in the Friday morning 0.4 mg/l and in the Friday afternoon 2.9 mg/l.
P Heikkilä, M Loutamo, V Riihimäki, M Romo
Sequential exposure of borate treated Douglas-fir to multiple Formosan subterranean termite colonies in a 40-week field test
1993 - IRG/WP 93-10006
Douglas-fir boards (ca. 74.5 g) pressure-treated with disodium octaborate tetrahydrate (DOT) retentions of 0 (controls), 0.88, 1.23, 1.60, or 2.10% (weight/weight) DOT were sequentially exposed to four active field colonies of Formosan subterranean termites, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), in an above-ground field test. Samples were placed in contact with each colony for 10 weeks, with oven-dry weight losses determined between exposures, for a total termi exposure period of 40 weeks. Feeding activity differed among termite colonies, with the control wood samples having mean weight losses of 1.3-15.1% of their initial weight during each individual 10-week termite exposure. The two lower borate retentions (0.88 and 1.23% DOT) were virtually equal efficacy, with mean wood weight losses during each individual 10-week exposure ranging from 1.2-4.6%. Feeding was negligible at the two higher borate retentions, with mean wood weight losses from termite feeding during each 10-week period ranging from 0.7-1.3% with 1.60% DOT, and 0.3-0.9% with 2.10% DOT. Total cumulative wood weight losses over the 40 week exposure were: 10.2% (0.88% DOT), 8.7% (1.23% DOT), 3.6% (1.60% DOT), and 2.4% (2.10% DOT).
J K Grace, R T Yamamoto
Analysis of creosote posts after 40 years of exposure
1994 - IRG/WP 94-50035
In the early 1950s The Western European Institute for Wood Preservation (WEI) started a program for testing creosote and salt treated posts in three exposure sites in Europe. Of these only the site in Simlångsdalen in south western Sweden remains today. The purpose with this investigation was to demonstrate which creosote components are still retained in the posts after 40 years of exposure and which components have migrated or evaporated. Three posts, impregnated with three different creosotes, from the site in Simlångsdalen have been studied. The retention, composition and distribution of creosote in the posts have been determined and compared with data on the original creosote. After 40 years of exposure creosote loss is greatest in the post impregnated with creosote containing the highest fraction of low-boiling constituents. The loss is greatest in the top sections of all three posts. The concentrations of low-boiling compounds (b.p. < 270°C), e.g. naphthalene and 2-methylnaphthalene are very low. The residual creosotcs have the greatest percentage of high-boiling constituents (> 315°C), especially phenanthrene and anthracene (b.p. 340°C). The soil close to those posts which were "over-loaded" with creosote during the treatment process, contains increased concentrations primarily of the heavier components fluoranthene, pyrene and chrysene. The small number of posts analyzed limits the possibility to generalize the conclusions.
G Bergqvist, S Holmroos
Copper naphthenate-treated Southern Pine pole stubs in field exposure. -Part 2: Chemical characterization of full size pole stubs 12 years after treatment
2000 - IRG/WP 00-30246
This study examines the influence of pre-treatment and post-treatment steaming on the character and physio-chemical nature of copper naphthenate in hydrocarbon solvent treated pine in larger, pole diameter, pole stub-length samples. This work is the continuation of two projects that began almost a decade ago. Previous reports indicated that certain morphological changes might occur in small laboratory steamed samples of copper naphthenate treated southern pine. Toluene-methanol extraction, UV-Vis spectroscopy, X-ray diffraction (XRD) and environmental scanning electron microscopy (ESEM) were used to investigate the nature and properties of the copper naphthenate present in the wood after 12 years of exposure. The formation of solid cuprous oxide occurred regardless of pre- or post-steaming conditioning.
H M Barnes, D P Kamdem, M H Freeman
An Australian test of wood preservatives. - Part IV: The condition, after 35 years' exposure, of stakes treated with creosote oils and oilborne preservatives
2000 - IRG/WP 00-30241
This paper contains the first results dealing with creosote oils and oilborne preservatives from this in-ground field trial in Australia. The substrates impregnated with preservative were Pinus radiata D. Don sapwood and Eucalyptus regnans F. Muell. heartwood and sapwood. Data are reported from stakes exposed for 35 years at three Australian sites (Innisfail, Sydney, Walpeup). Comparisons were made between preservatives impregnated into P. radiata at 128 kg/m³ and exposed at Sydney. After 35 years, the mean condition of stakes treated with British standard, Australian K.55 (blend) and brown coal tar (high residue) creosote oils were serviceable. The mean condition of stakes treated with USA standard (AWPA P.1), Australian K.55 (ii, old Timbrol) and brown coal tar (distillate) creosote oils was unserviceable (ie. rated 3 or less out of 8). When a proportion of Australian K.55 (blend) creosote oil was replaced by furnace oil, vertical retort tar or 2.5% pentachlorophenol (PCP) in furnace oil, the new combinations did not, on average, rate as highly as the Australian K.55 (blend) creosote oil by itself. PCP was compared at 6.4 kg/m³ in P. radiata at Sydney. 5% PCP in furnace oil (128 kg/m³) performed as well as Australian K.55 (blend) creosote oil and much better than 5% PCP in diesel fuel oil (128 kg/m³). 2.5% PCP in furnace oil (256 kg/m³) rated the highest of any treatment containing 6.4 kg/m³ of PCP. The addition of dieldrin or chlordane improved the efficacy of 2.5% PCP in furnace oil (128 kg/m³) at Sydney, but not at Innisfail. The addition of benzene hexachloride showed greater protection than dieldrin or chlordane.
G C Johnson, J D Thornton
Biocides - Efficacy assessment and doses for wood preservatives (product type 8). Local/geographical aspects. Termite control as case study
1999 - IRG/WP 99-20181
Currently, the efficacy of a wood preservative, as biocidal product type 8, is assessed as a ‚critical value' (CV), an efficient dose (retention in wood at a given depth of penetration). CVs are planned to be adapted for exposure to basic target organisms (5 hazard classes) and additional requirements concerning the occurrence of local target organisms in relation with climate, building design and relevant economical impact. Among them, the termite case study is illustrative. The vote of a french law, on 26 may 1999, aiming to protect consumers and to organize termite control puts termites, a "local target at the euro scale and a universal one in some euro territories", in the spotlights of actuality and helps to point out some of the remaining questions raised by the implementation of Dir 98/8 on Biocides. Based on CEN/TC/38 simulated use tests, which doses have to be used for conditions of exposure and climate, ranging from polar to tropical? Practical proposals are made to take into accound local prescription based on actual target organisms, and move on to standard biocide profiles.
Environmental exposure to wood preservatives
2000 - IRG/WP 00-50165
The OECD Working Group on Pesticides will hold a workshop on Assessing Environmental Exposure to Wood Preservatives within the context of its Biocides Programme (cf. IRG/WP 99-20182). In the area of risk assessment, OECD countries have given highest priority to developing guidance on how exposure assessments for biocides should be performed. Wood preservatives have been selected since most countries have experience in regulating them. The workshop will cover environmental exposure resulting from professional and non-professional use during: ·the application of wood preservatives to treat wood, including the storage of treated timber prior to use; ·the use of the treated wood and products made from it; ·disposal (including burning, dumping, etc) and re-use/recycling. The workshop will also cover emissions to air, water/sediments and soil, as well as fate and behaviour in those compartments including exposure through the food chain. Regarding exposure via the food chain, the principal focus will be on secondary poisoning in the environment (e.g. worm-eating birds), although the potential for human exposure via the environment (e.g. via groundwater) may be also addressed to a limited extent. Since the outcome of the OECD workshop has a large potential of influencing wood preservation environmental research in the IRG member countries, a report will be given about the consequences of the OECD activities with special focus on the future objectives of IRG Section 5.
Biological effectiveness of ground-contact wood preservatives as determined by field exposure stake tests
1984 - IRG/WP 3297
Field exposure tests conducted on stakes treated with different creosotes, mixtures of creosote and waxy oil as well as different CCA wood preservatives over a period of 25 years, gave the following results: The CCA preservatives provided excellent biological protection to treated stakes, especially against fungal attack. The CCA Type I, currently approved for use under South African conditions is not inferior to the CCA Type II during long-term ground-contact exposure if the active elemental contents and effective retentions are taken into consideration. The creosotes provided good protection against termite attack but showed fairly poor fungal resistance during long-term ground-contact exposure under wet conditions. The addition of waxy oil greatly improved the effectiveness of creosotes against fungal attack. The CCA preservatives proved to be a better overall ground-contact preservative compared with the creosotes.
W E Conradie, A Pizzi