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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


Results of co-operative studies on determining toxic values against wood-destroying Basidiomycetes. Preliminary report to Sub-group members
1986 - IRG/WP 2271
A F Bravery, J K Carey


The Role of Coformulants in Preventing Bacterial Biotransformation of IPBC
2002 - IRG/WP 02-10436
The inhibitory effects of disodium tetraborate decahydrate and benzalkonium chloride (BAC), two common coformulants of IPBC in antisapstain treatments, on an IPBC-transforming enterobacterial isolate ‘W1’ were determined by their effect on the specific growth rate constant in vitro. The IC50s of IPBC, BAC and borate were found to be 0.46, 0.026 and 5.7 mM respectively. The IC50 of the Arch antistain product AntibluTM Select was 0.024 mM, based on its BAC content. Although their IC50’s were significantly different, it was clear that the vast majority of the bacterial toxicity of the AntibluTM Select was due to its BAC content. The degradation of 0.4 mM IPBC by the bacterium W1, as measured by the accumulation of its degradation product, iodide, in liquid culture, was completely inhibited by BAC concentrations greater than 18 μM, and the toxicity of the spent culture medium to Aspergillus niger, as measured by an antibiotic assay disc assay, was not ameliorated above this concentration. Below 18 μM, the toxicity of the spent broth was significantly reduced, and the accumulation of iodide occurred rapidly. Demonstrating the toxicity of BAC to bacteria, and its consequent inhibition of IPBC degradation in vitro, are indicative of the importance of coformulation in controlling bacteria that might otherwise cause preservative loss, and of their significance in determining the ultimate environmental fate of cobiocides.
S R Cook, D J Dickinson


Laboratory study on the effectiveness on photostable pyrethroids formulated with benzalkonium chloride to be used on furniture
1985 - IRG/WP 3346
The first results are presented of a study on the effectiveness of photostable pyrethroids formulated with banezalkonium chloride. Initially the products were submitted to preliminary tests and then the more efficient formulations were tested with a new essay that tries to simulate a dry-wood termite attack on furniture.
A M F Oliveira, A T De Lelis


The effect of temperature on the rate of fixation of an alkyl ammonium compound (AAC) wood preservative
1984 - IRG/WP 3293
The rate of fixation of an alkyl ammonium compound wood preservative was measured by soaking samples of wood wool in various preparations of the preservative for arbitrary times followed by immediate leaching in water. The wood wool was then analysed for residual preservative. The results indicated that fixation was very rapid and increased at higher temperatures.
P Vinden


The preliminary evaluation of selected sulfonium salts for use in wood preservation
1984 - IRG/WP 3278
Five sulfonium compounds, including two sulfonium methosulfates, one sulfonium bromide and two amphoteric sulfonium propanesulfonates, were prepared in crude form and subjected to various biocidal screening tests. A rapid screening test in which treated Pinus radiata pulp pellets were exposed to one of three wood-decaying fungi growing on malt agar revealed that dodecyl dimethyl sulfonium methosulfate had an inhibiting effect comparable to that of lauryl dimethyl benzyl ammonium chloride (benzalkonium chloride). The remaining sulfonium salts gave no fungal inhibition in this test. Both dodecyl- and decyl dimethyl sulfonium methosulfate gave a positive response in a screening test for insecticidal activity. However, rapid insect recovery indicated detoxification or excretion of the test chemicals. Dodecyl dimethyl sulfonium methosulfate was also screened as an anti-sapstain treatment with encouraging results. Further work is now in progress to explore the potential wood preservative capability of certain sulfonium and sulfoxonium salts.
D V Plackett


Field tests of preservative-treated radiata pine in Japan
1995 - IRG/WP 95-30083
Test stakes of radiata pine treated with various alkyl ammonium compound (AAC) formulations and with copper-chrome-arsenate (CCA) as reference preservative were installed in 3 test sites in Japan in 1981-82. When inspected in 1995, CCA-treated stakes showed less decay at all three sites than stakes treated with other formulations. Ammoniacal copper quaternary (ACQ)- treatment was only slightly less effective than CCA at two sites (Tsukuba and Fukiage-Hama), but more markedly less effective at the high decay hazard Uji site. Unamended AAC treatment was least effective, but there was little difference in performance between didecyl dimethyl ammonium chloride (DDAC) and benzalkonium chloride (BAC) formulations.
M E Hedley, K Tsunoda, K Suzuki


Development of a mini-block test method for the rapid evaluation of preservative performance against Basidiomycte fungi
1991 - IRG/WP 2379
Screening procedures for new biocides used as wood preservatives can be a time consuming process using conventional Basidiomycete assay procedures. This is due mainly to the long exposure periods required to achieve adequate levels of decay (weight loss) in the test blocks. A number of alternative methods have been developed but most utilise artificial substrates such as filter paper or agar in which inhibition of growth is the main criterion of efficacy assessment. Whilst these methods can provide a comparison of biological activity towards target fungi, they omit the interaction between wood substrate and active ingredient. A further limitation is the inability of these methods to determine preservative performance. A test method has, therefore, been developed based on conventional methodology but using small dimension samples and a reduced exposure period (3 weeks). Results have indicated good test reproducibility with high weight losses of untreated controls. Large numbers of active ingredients or formulations can be rapidly screened using this method and the data can be further used for the estimation of treatment concentrations required for more formal basidiomycete tests such as EN 113.
J Brown, S Caswell, G R Williams


The Protection of Plywood with Benzalkonium Chloride (BAC) Wood Preservative
2002 - IRG/WP 02-40219
Alkyldimethylbenzyl ammonium chloride (benzalkonium chloride) (BAC) and alkyldimethylamine acetates were approved by the Timber Preservation Authority of New Zealand in 1978 for the protection of radiata pine that was destined for above ground, weather exposed applications. As a result of continuing failures, the use of AACs was stopped in New Zealand in the mid 1980s. The Plywood Association of Australia (PAA) was interested in the use of AAC wood preservatives because the preservative could be used to treat veneers before gluing without affecting the glue-bond strength. Treating the veneers also leads to a more uniformly treated product. A field exposure trial of AAC treated plywood using plywood treated to much higher levels than those used in New Zealand, was established in November 1992. The exposure was assessed annually for three years, after which time a limited approval was granted for use under the Timber Utilisation and Marketing Act (TUMA) of Queensland. At that time, there was no approval for use of BAC in the Australian Standard AS 1604. Assessment of the trial was suspended until mid 2001, nine years and seven months after initial exposure. All panels in the exposure were reassessed at this time and the results indicate that the BAC, used at the higher retention provided good protection for weather exposed, out of ground contact applications.
J Norton


Benzalkonium chloride (an AAC preservative): Criteria for approval, performance in service, and implications for the future
1985 - IRG/WP 3328
The data base generated for benzalkonium chloride was considered adequate for commercial approvals, particularly after revision in late 1982. Field trials, although not part of the approval criteria, generally supported commercial use; decay observed in one test (post and rails) after 6 years' exposure would have resulted in some caution in setting retentions. No laboratory trial, nor field trial, could have predicted the problems experienced during commercial operations. Substandard treatment was interpreted as being responsible for most of the insect attack and decay problems. The remainder were caused by misuse in service, depletion (by chemical or, less likely, by biological mechanisms) during long-term wet storage, or attack by apparently highly AAC-tolerant Coniophora spp. A strict protocol for preservative approvals is now being drawn up which will reflect a higher degree of conservatism and much more reliance on long-term field trials, even of above-ground commodities.
J A Butcher


Measurement of electrokinetic potential to evaluate adsorption of quaternary ammonium salt
1991 - IRG/WP 3672
Measurement of z-potential in the wood treated with preservatives is suggested as a method for determination of the adsorption of preservative to wood. It has been found that measurement of z-potential of wood treated with quaternary ammonium salt type preservatives can be a useful method to determine the adsorptives phenomena of preservatives and by which there is a remarkable differences in the adsorbed condition with the components of preservatives concentration of treating solution, treating time and the elapsed time for streaming potential measurement in wood treated with quaternary ammonium salt type, there were differences in values of z-potential against that of untreated wood with a difference in chemical formula of preservatives, addition of chemicals for polymerization and concentration of treating solution. In case of the wood treated with quaternary ammonium salt with silicon, the treating time to reach the completly adsorbed condition of preservatives was about 3-5 minutes in concentration of below 0.75% and was about 15 minutes in above 1.5%. On the other hand, in adsorption of benzalkonium chloride, it took 15 minutes of adsorbing time in below 0.75% and 7.5 minutes in above 1.5%. Regardless of the extension of elapsed time for measuring, the constant values in z-potential was not obtained in wood treated with quaternary ammoniusalt with silicon, this result was attributable to leaching of preservatives. Whereas, for measurement of wood treated with benzalkonium chloride, it took the measuring time of 15-20 minutes to obtain constant values which mean a stable condition in adsorption.
Yeong Suk Kim


Cytochemical localization of hydrogen peroxide in brown rot fungus Tyromyces palustris by cerium chloride technique
1999 - IRG/WP 99-10299
Cerium chloride (CeCl3) was used to localize H2O2 cytochemically for studying relationship between ultrastructural and functional characteristics of cellulose degradation by brown rot fungi. This technique proved very useful in localizing discrete electron-densereactionproducts at high resolution with minimal nonspecific deposition. The cytochemical localization of extracellular H2O2 by CeCl3 using TEM demonstrated the presence of H2O2 within the fungal hyphae. Furthermore, our results give an indication of the diffusion of extarcellular H2O2 from brown-rot decay fungi into the intact wood cell walls in the early stages of decay.
Yoon Soo Kim, Seung-Gon Wi


Patent on the use of tannic acid and ferric chloride against marine borers, etc
1982 - IRG/WP 495
R Mitchell, T D Sleeter


The effect of didecyldimethylammonium chloride on growth of different strains of mould fungus Gliocladium roseum
1995 - IRG/WP 95-10105
The tolerance and degrading ability of different strains of Gliocladium roseum towards didecyldimethylammonium chloride (DDAC) were studied. All four of the strains of Gliocladium roseum were tolerant to DDAC and after their growth on amended malt agar, the retention of DDAC in the medium was reduced.
Yu Zheng, J N R Ruddick


Tests on preservation of wood against marine borers
1976 - IRG/WP 417
The Instituto del Legno has carried out for some years a series of trials about the biodeterioration of wood in the sea. The investigations included the settlement and activity of marine borers, the natural durability of indigenous and tropical woods and the preservation of wood for marine use. This paper reports the trials on the effectiveness of some preservatives in protecting wood against marine borer attack. The trials were carried out at Follonica station, where some investigations had shown that untreated pine samples submerged in the sea were totally destroyed by marine borers within 1 year. Follonica station, latitude 42° 55' North and longitude 10° 45' East, is situated on the Tyrrhenian sea. The recorded temperature varies between 12°C (January to March) to 25°C (July to September), salinity between 37 to 38% and pH about 8. The borers observed in wood were: Nototeredo norvagica Spengler, Bankia carinata Gray, Limnoria tripunctata Menzies and Chelura terebrans Philippi.
A Gambetta, E Orlandi


Variation in Canadian bluestain fungi: Tolerance to DDAC and DOT
1999 - IRG/WP 99-10303
Bluestain in Canadian wood products results in significant and unpredictable losses each year. In order to develop rational methods to eliminate or reduce the sapstain problem, a more complete knowledge of the causal organisms must be gained. This includes a knowledge of the variability in tolerance of different fungal species and strains to commercially used chemicals. In British Columbia, the majority of anti-sapstain chemicals are based upon the quaternary ammonium compound DDAC, either as the sole active ingredient or in formulation with co-biocides such as disodium octaborate tetrahydrate (DOT). Ten strains each of the three most prominent blustain fungi found in Canada (Ophiostoma piceae, Ophiostoma piliferum, and Graphium (species C)) were evaluated for their tolerance to DDAC and DOT. The main findings showed there was little or no variation in the tolerance to the chemicals within the strains of each species tested. In the screening tests it was found that DDAC was less effective in inhibiting fungal growth than DOT. However, further examination revealed that the ineffectiveness of DDAC was due to interactions with the media components - a reminder that care must be taken when evaluating results especially with surfactants such as DDAC. Additional work with other sapstain control chemicals is underway.
J Dubois, A Byrne, J E Clark, A Uzunovic


Effect of borate on uptake and efficacy of an anti-sapstain treatment
2005 - IRG/WP 05-30380
The potential for using borates to enhance uptake and efficacy of propiconazole-based anti-sapstain chemicals was assessed on ponderosa pine sapwood wafers. Borates had no consistent effect on either net solution absorption or propiconazole distribution in the wood. Even small amounts of borate, however, markedly improved the performance of propiconazole against fungal discoloration. These results are consistent with previous tests of borate addition to other fungicides and highlight the potential for using less expensive ingredients to boost the performance of more costly biocides.
Jianju Luo, Hua Chen, J J Morrell


Investigation of the fixation in wood of chromated zinc chloride and copperised chromated zinc chloride preservatives
1976 - IRG/WP 372
A biological method of evaluating the extent to which CZC and CCZC preparations are retained in wood in terms of the potential protection which they afford against destruction by Merulius lacrymans (dry rot) is given. CCZC is recommended for protection of wood under moderate leaching conditions, while the use of CZC under such conditions is not recommended.
V N Sozonova, D A Belenkov


Photo-discoloration and Degradation of Wood and its Stabilisation by Modification with Benzoyl Chloride
2004 - IRG/WP 04-40274
Photo degradation of Pinus roxburghii (chir pine) and Hevea brasiliensis (rubber wood) was studied under artificial accelerated weathering conditions in a Xenon test chamber. The irradiated samples were analyzed for color changes and chemical changes. Analysis of colour changes in wood surfaces by UV-Vis. irradiation was carried out using a colour measuring (CIELAB) system and chemical changes were monitored using FTIR and fluorescence spectroscopy. Irradiation modified physical and chemical characteristics of wood surfaces and resulted in rapid colour changes, reduction in lignin content and increased concentration of chromophoric groups on the wood surfaces. Colour changes were correlated with formation of carbonyl groups and lignin decay rate determined by FTIR measurements. Fluorescence emission spectra measured from un-weathered wood shows excitation wavelength dependence. Photo irradiation leads to a rapid reduction in the emission intensity, broadening of spectra and a significant red shift in the emission maximum. Photo stability of wood surfaces esterified with benzoyl chloride was also assessed. The modification was characterized and analyzed by fluorescence and FTIR spectroscopy and photo-stability of modified wood was assessed. Esterification of wood by benzoyl chloride suppressed the colour changes (photo-discoloration) and also reduced the lignin degradation and generation of carbonyl groups on irradiated wood surfaces. Results show esterification of wood with benzoyl chloride was effective at inhibiting photo-degradation of wood polymers.
K K Pandey


An investigation of organotin compounds in treated wood using Mössbauer spectroscopy
1983 - IRG/WP 3249
The influence of sample preparation on the 119mSn Mössbauer spectrum of tributyltin chloride in ponderosa pine was investigated. Initial studies with sawdust and compressed discs concluded that the latter were clearly superior. Further studies showed that compressed discs prepared from 0.4 g of treated wood and 0.1 g of cellulose were robust and gave excellent Mössbauer spectra. The possibility of improving the Mössbauer resonance by increasing the solution concentration was evaluated, and found to be beneficial, with no change in the fixation process being evident at least up to 6.9% solution strength. Wooden cores were assessed as alternative test material since they are less prone to disintegration. The Mössbauer spectrum of tributyltin chloride in wood was obtained and analyzed with the aid of point charge calculations. It was concluded that when impregnated into wood, tributyltin chloride either remains polymeric with bridging chlorides or adopts a mer-trigonal bipyramidal geometry with hydroxyl donor bonding from the cellulose. Investigation of tributyltin-, dibutyltin- and monobutyltin-chlorides following impregnation into wood suggested that, while the monobutyltin-derivative may be easily identified when present, it is doubtful whether the tributyltin- and dibutyltin- complexes will be distinguishable using simple Mössbauer spectroscopy. Modifications were therefore proposed for the technique which would allow the triorgano- and diorganotin species to be identified when present as mixtures in wood.
J N R Ruddick, J K Ingram


Composting of waste building up in sawmill dipping basins
1990 - IRG/WP 3570
We have studied composting of waste building up in dipping basins at sawmills although this waste can also be disposed of by incineration. Controlled composting within the sawmill area seems to be a feasible method. Another possibility is to accomplish composting directly at the local dumping site. Waste containing antistain chemicals is generally classed as hazardous. It cannot therefore be placed as such at common dumps. However after successful composting the permission to do so can probably be obtained. The composted dipping basin waste might also be suitable as land filling or in some cases as soil improvement material - at least in parks and green belt areas.
I A Linderborg, U Ek


Marine trials with water-borne salts and organotin compound
1986 - IRG/WP 4128
Pinus sylvestris blocks treated with water-borne salts (CCA, CCB, CCF) and organotin compounds (TBTO, TBTCl) were submerged in the sea at Follonica station. The results obtained after 12 years of immersion are presented. The samples treated with CCA, CCB and CCF at the lowest concentration (2%) were destroyed after 7-9 years and the samples treated with CCB and CCF at the highest concentrations (4%, 6%), which were tested for a longer time than CCA treated samples, were destroyed after 11-12 years. The samples treated with organotin compounds did not show any attack by molluscan borers after 12 years with the exception of those treated with TBTCl at the lowest concentration (0.5%). The organotin compounds were less effective against crustacean borers.
A Gambetta, E Orlandi


Leachability of didecyldimethylammonium chloride (a quaternary ammonium compound) from four wood species
1982 - IRG/WP 3204
Sapwood blocks prepared from red pine, ponderosa pine, southern yellow pine and hem-fir (a commercial mixture of western hemlock and amabilis fir) were treated with didecyldimethylammonium chloride, (an alkylammonium compound, AAC). After oven drying the blocks were vacuum impregnated with distilled water and subjected to a static leach cycle for 48 hours. The leachate was analyzed and the amount of AAC which leached from each wood species, calculated. The results showed that the leaching of didecyldimethylammonium chloride from ponderosa pine was not unusual, and that the amount of AAC leached for the various wood species increased in the order > red pine > ponderosa pine > southern yellow pine > hem fir.
J N R Ruddick, A R H Sam


Efficacy of Didecyl Dimethyl Ammonium Chloride (DDAC), Disodium Octaborate Tetrahydrate (DOT), and Chlorothalonil (CTL) against Common Mold Fungi
2004 - IRG/WP 04-30338
The fungitoxic properties of four fungicides, alone and in combination, against four different mold fungi commonly associated with indoor air quality problems were evaluated on two different wood species and sheetrock. The fungicides were chlorothalonil (2,4,5,6-tetrachloroisophthalonitrile) (CTL) in a 40.4% aqueous dispersion, disodium octaborate tetrahydrate (DOT) in two different forms - a 40% glycol solution and a 98% wettable powder, and didecyl dimethyl ammonium chloride (DDAC) in an 80% solution. The fungi were Aspergillus niger, Cladosporium cladosporioides, Penicillium brevicompactum, and Stachybotrys chartarum. All fungicide treatments on wood reduced growth, sporulation and discoloration of the mold fungi when compared to nontreated specimens. No single fungicide provided total control of all four fungi on wood. CTL provided the best single-agent protection by totally preventing the growth of C. cladosporioides and S. chartarum and reducing growth of A. niger and P. brevicompactum to low levels. DOT in both forms was very effective against A. niger, but provided only sporadic protection against other fungi. DDAC provided good protection against S. chartarum but was not as effective against the other molds. Combinations of the different biocides were more effective than any single agent. DOT + DDAC totally prevented or greatly reduced growth of A. niger, P. brevicompactum and S. chartarum. Cladosporium cladosporioides was the most difficult organism to control, but even this was achieved when DDAC was increased to 1.0% with DOT. The most consistent control of discoloration, sporulation, and growth of the fungi on wood was obtained with the combination of DOT and CTL. DOT, alone or in combination with DDAC or CTL, was also very effective against the fungi on sheetrock. The results suggest that by using appropriate products, during construction or after water damage, problems associated with the growth of common molds and their potential health effects can be avoided.
J A Micales-Glaeser, J D Lloyd, T L Woods


Movement of water through quaternary ammonium treated wood
1987 - IRG/WP 3440
Radiata pine sapwood stakes were treated with didodecyl methyl 1, 3 dichloropropenyl ammonium chloride and distearyl dimethyl ammonium chloride. Various ratios of these two chemicals were, tested to determine the extent of water movement through the treated wood. Measurements were taken of the amount of water moved through the wood, degree of wetting of various sectors of the stakes, and the distribution of the quaternaries through the stakes. The results showed that didodecyl methyl 1,3 dichloropropenyl ammonium chloride increased the amount of water movement through the stakes compared to untreated, however the addition of distearyl dimethyl ammonium chloride reduced the water movement to below that of untreated. Over the twelve weeks of the trial no redistribution of quaternaries was noted.
P J Hayward, J Duff


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