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New technique to analyze impregnation processes
1988 - IRG/WP 2304
Equipment has been developed to measure liquid flow in wood during impregnation processes. Basic principles of flow measurements using directly heated negative temperature coefficient thermistors, and some characteristics of the hardware developed are presented in this paper.
J P Hösli

Current techniques for screening initial formulations against Basidiomycetes and soft rot
1978 - IRG/WP 2103
J D Thornton, H Greaves

A summary of current information on actinomycetes and wood
1978 - IRG/WP 177
B King, R A Eaton, A A W Baecker

A survey to assess the current and future usage of timber in British port structures
1998 - IRG/WP 98-10247
Port engineers responsible for 30 British ports were surveyed by questionnaire or interview to establish current and prospective usage of timber in those ports. The ports surveyed account for about 25% of total cargo handled annually in Britain and being located all around the British mainland, were considered to form a representative sample. The survey identified the hardwoods and softwoods in use for various applications in port structures, the criteria for selecting materials for these structures, the materials considered most suitable for piles and fenders and the types of preservative specified. Additional data was collected on the current condition of structures, incidence of marine borers, experience and training of port engineers and their attitude towards timber.
G S Sawyer, S E M Plaster

Current and future options for managing used preservative-treated wood
1995 - IRG/WP 95-50042
The amount of preservative-treated wood available for disposal will continue to increase exponentially in the next several decades as landfill availability declines. At the same time, recent legal ruling on competitiveness among utilities and disposal of ash has clouded the economic outlook for combustion of treated wood for energy recovery. This report identifies current and future options for managing used preservative-treated wood, as well as technological and environmental/regulatory limitations to these options. Re-use, recycling (particularly through the manufacture of wood-based composites), and biodegradation are described as primary alternatives to land disposal and combustion. The report also describes supporting technologies (analytical methods and comminution) for managing used treated wood.
R C De Groot, C Felton

A discussion of current theories concerning CCA fixation
1983 - IRG/WP 3238
The understanding of the fixation mechanism of CCA and related preservatives in wood has been greatly improved by a significant series of recent scientific papers. In view of recent concerns in New Zealand regarding the long-term efficacy of CCA in high decay-hazard situations, it was considered appropriate to review this recent work and to contrast it with theories presented by previous workers.
D V Plackett

Current models used by the European Health Authorities to evaluate the volatilization of active ingredients from treated wood used inside dwellings. A case study: Volatilization of azaconazole and propiconazole from treated wood
1990 - IRG/WP 3565
The use of wood preservatives inside houses may result in measurable aerial concentrations of active ingredients. These airborne contaminants may be inhaled by the inhabitants over periods lasting from a couple of days to several months. To assess the potential health hazard of preservative residues in the air, various risk-assessment models have been worked out. Three schemes, currently used by the European health authorities, are discussed in this paper. They are based on the saturated air vapour concentration, the volatilization rate measured in laboratory experiments and the aerial concentrations determined in practice. For each model various safety margins can be calculated. These are based on e.g. the subchronic inhalation toxicity, the acceptable daily intake and the acceptable aerial concentration of the insecticides and fungicides used in wood preservatives. In order to demonstrate the feasibility of these health- assessments, a case study has been carried out with the fungicides azaconazole and propiconazole, developed by Janssen Pharmaceutica - Belgium.
A R Valcke, L Van Leemput

Restriction for use and waste management for pressure treated wood - The current situation in Norway
2001 - IRG/WP 01-50175
The Norwegian Environmental Authorities have this winter sent out a draft on restrictions in production and use of heavy metals in preservative treated timber. If it is passed, it will lead to drastic changes in the use of preservatives in Norway from this autumn. The environmental authorities and the preservative industry are both at present discussing waste management for CCA and creosote treated wood.
F G Evans

Decay, decayed wood and the Shigometer
1980 - IRG/WP 281
A L Shigo

A behaviour of CCA penetration of fir (Abies bornmulleriana Mattf.) at different ramp times and constant vacuum/pressure applications
2006 - IRG/WP 06-40346
A behaviour of CCA penetration of Bornmulleriana fir (Abies bornmulleriana Mattf.) at different ramp times and constant vacuum/pressure applications was illustrated for the main flow directions by the experimental pictures.
I Usta, R Despot, M Hasan

Wood Preservation India; Current Scenario
2013 - IRG/WP 13-40630
This short note describes the present status of wood preservation research and its industrial application. Although good performing formulations have been developed by Indian research laboratories, industry has not tried to derive benefits from this development. Many unknown products are flooding the market for brush on applications with little benefit as the products have not been standardized.
S Kumar

Evaluation of the pulsed-current resistance meter (Shigometer®) for determination of the internal condition of utility poles
1979 - IRG/WP 2128
A number of Telecom poles, which had been removed from service to be replaced by a radio link, were inspected using an electrical resistance meter (Shigometer®). These poles were creosoted, non-durable Victorian species in service in New South Wales. Six of these poles, chosen to represent various internal conditions typical of the range of the population tested, are discussed here. Data, from traditional assessment methods on the standing poles, from visual inspection, drilling and resistance testing after crosscutting, are presented together with photographs of a section of each pole. These data are presented to familiarise the reader with the obtaining and interpretation of electrical resistance values and to enable the reader to decide for himself whether this type of instrument may be a reliable and useful aid to the person determining the internal condition of service poles.
J D Thornton, W G Seaman, M McKiterick

Possibilities of improving the oscillating pressure method
1991 - IRG/WP 3668
Studies on the dynamics of pressure changes in wood during impregnation revealed no significant effect of fast pressure changes for green spruce as used by OPM (IRG/WP/3615). The following experiments were carried out on several hundreds of spruce palisades to examine the modification of single procedure parameters of common use OPM and to record the effects on the impregnation result with the aim of simplifying the energy and cost expensive technique, retaining the same or possibly an improved treatment quality. The samples were endsealed and impregnated with CCB (4%), their actual effective substances being defined by AAS at the beginning and at the end of the treatment. Generally, programme variants with several pressure changes, independent of their number, duration and dynamics, resulted in a better penetration of the sapwood than programmes where a constant pressure was used. Fast pressure alternation within a few seconds did not result in a noticeable better impregnation quality. A dynamic change of the phase lengths and of the distribution quotient for pressure and vacuum respectively atmospheric pressure did not improve the treatment result. Sapwood moisture content between 100 and 180% are optimal preconditions for a good treatment quality.
S Goetsch, R-D Peek

Comparison of variable, constant and fluctuating pressure methods
2001 - IRG/WP 01-40212
The objective of this work was to evaluate potential improvements in pressure treatment arising from the use of a control valve. A constant pressure of 1035 kPa was compared to the conventional variable pressure method where the pressure is allowed to drop to 860 kPa as the solution is absorbed by the wood. A fluctuating pressure method (FPM) where the pressure cycles between 1000 and 1070 kPa was also evaluated. With unincised western hemlock, the results were in the order FPM>constant>variable pressure. Incising acted to moderate differences in preservative penetration among treatments. With incised material, results were in the order constant>FPM>variable pressure. This work has resulted in the installation of control valves as upgrades to several existing treating plants. Further work is required to determine if the FPM process has benefits compared to constant pressure in commercial practice.
S M McFarling, P I Morris

The effect of rate of pressure application on preservative uptake along and across the grain of fir (Abies bornmulleriana Mattf.) at different ramp and constant pressure times
2004 - IRG/WP 04-20292
This study was particularly design to determine the preservative uptake at different ramp (rate of increase in pressure) and constant pressure times on longitudinal, tangential and radial penetrations of fir (Abies bornmulleriana Mattf.) which grown indigeneously in Turkey. The samples of 2 cm cubes of kiln-dried wood (nominated to 12% moisture content) were treated at different ramp times varied from very fast to very slow rates of pressure (bar) per time (seconds) at 5, 15, 30, 60, and 90 sec. and the maximum pressure of 4 bars -in the treating vessel to refusal- was applied at the constant pressure time for 5 min. The preservative uptake was determined as the percentage of void volume filled (VVF%) for either flow directions at each ramp time. The results showed that the VVF% was, as expected, markedly greater in the longitudinal flow direction than both in the tangential and radial flow directions. In comparison to the VVF% laterally, it was greater in tangential direction than in radial direction in either treatment schedules. In this issue, although the trend seemed to be the similar between the flow directions, quite different patterns were observed within each direction for penetration and ramp times. Accordingly, conclusions were listed separately for each flow direction.
I Usta

Quality assured wooden sidings - Criteria, performance evaluations and current status
2000 - IRG/WP 00-20216
Quality assured wooden sidings were brought to the Swedish market in 1998. The system was worked out during a six year period in a close cooperation between the sawmill industry and several research institutes. Centuries of use have given a wealth of experience of spruce boards as a siding material, showing that it works well in most cases but also that its longevity is highly variable, depending on the wood raw material, climatic conditions, and not least the coating system. The quality assurance system sets criteria for the quality and the freshness of the wood, for the industrially applied primer, for acceptable time limits in each processing step, and for construction and design. Particularly sensitive parts, such as board ends, are treated with an oil product containing fungicides. The durability of a siding will still be subject to considerable variations, but the service life and the maintenance intervals can be predicted with more confidence, and these times are substantially lengthened. This gives added value to the product, to the benefit of the consumer. Examples from the criteria development are given with some field tests where boards with exposed radial or tangential surfaces are compared, and where attempts to provoke premature failure was made by extending the panel ends close to the ground.
F Englund, I Johansson, J Ekstedt, R Nussbaum

Current status of AAC preservatives in New Zealand
1980 - IRG/WP 3141
Two types of alkylammonium compounds (AAC) have been approved as commercially acceptable wood preservatives by the NZ Timber Preservation Authority (TPA). They are alkyldimethylbenzyl ammonium chloride and alkyldimethylamine acetate, both of which must contain either (a) 70% alkyl chains of C12 + C14 and less than 10% of any other individual chain length, or (b) 85% alkyl chains of C12 + C14 with no restriction on percentage occurrence of any other chain length. Existing approvals cover formulations of the quaternary ammonium compound and of the tertiary, amine salt. Approvals for use are currently restricted to Pinus radiata and to those commodities which do not involve ground contact. For interior building timbers (Commodity Specification C8), where protection is required only against insects, the minimum charge retentions and core loadings are: Alkyldimethylbenzyl ammonium chloride: 1.5 kg/m³ and 0.1% w/w; Alkyldimethylamine acetate: 1.0 kg/m³ and 0.07% w/w.
J A Butcher

EPA’s Current Views on Heavy-Duty Wood Preservative Regulation
2003 - IRG/WP 03-50206
This paper describes the current EPA system for regulating pesticides and wood preservatives. In particular it focuses on the voluntary phase-out of CCA for residential uses after December 30, 2003, which was agreed between the CCA manufacturers and EPA. Even though the EPA reached an agreement with industry to phase out CCA for residential uses, EPA is continuing the most rigorous risk assessment ever done on a wood preservative pesticide. One risk assessment is considering children’s exposure at residential sites and the other focuses on the uses that are not subject to the phase-out agreement, e.g. fence posts and wood in permanent foundations.
F T Sanders

Review of current wood preservation in Turkey
2003 - IRG/WP 03-30315
The aim of this study was to find out the current potential of the Turkish wood preservation industry, and to make some suggestions for its further proceeding, because the forest products potential and the geographical location combined may give to the wood preservation industry in Turkey a great advantage for exportation treated wood materials to the Middle East Countries. In this study, therefore, the importance of wood preservation in the country was discussed and the measurements were described. The regulations, standards and other specifications in current use relevant to the subject in Turkey have also been criticized. Consequently, it can be stated that this research offered the essential data concerning the timber resources in Turkey, the country’s most dangerous wood-destroying organisms, the wood preservatives available, the facilities that exist in the country for wood preservation, and the universities and research institutes that are concerned with protecting wood.
I Usta

Termite physical barriers: Current status of retrofitting Granitgard around 'mock-up' buildings
1994 - IRG/WP 94-10057
Two years ago a field experiment was designed and installed to evaluate the effectiveness of Granitgard, the commercial name of a grade of crushed granite rock, as a termite physical barrier when retrofitted around 'mock-up' buildings. The field station is located at Walpeup in the semi-arid mallee region of northern Victoria (360 km north of Melbourne), and there are several indigenous subterranean termite species at the site. After 20 months, no foraging by Coptotermes species has occurred in the 'mock-up' buildings. It seems that these termite species (the most economically important termite species in Australia) have not breached the trenches filled with Granitgard alone, and with a mix of Granitgard and chlorpyrifos. While it may be too early to declare that retrofitted Granitgard around existing buildings prevents subterranean termites gaining access to the building, there is no doubt that Granitgard does affect subterranean termite foraging behaviour. However, this effect is accomplished without detrimental environmentally side-effects. Granitgard is approved as an alternative to soil chemical barriers when installed under newly constructed buildings in the latest Australian Standard (AS 3660 -1993). The current results of the retrofitting experiment suggests that there may well be a practical role for such a physical barrier in the protection of existing buildings as well. This paper describes the results of the field evaluation of Granitgard when used as a retrofitted barrier around 'mock-up' buildings after two years in a field test. We discuse the implications of these findings and where they fit into future integrated pest management strategies for termite control.
J R J French, B M Ahmed

The effect of moisture content on the electrical resistance of timber as detected by a pulsed current reistance meter (Shigometer)
1984 - IRG/WP 2212
The literature concerning the use of the Shigometer® for detecting decay in standing trees and wood poles is reviewed and the differences of opinion over the effect of timber moisture content on electrical resistance are highlighted. A simple experiment designed to test this effect is described and the implications of the results for testing poles in service are discussed. There was a large difference between the electrical resistance of timbers below 38% and above 45% moisture content. In sound poles, moisture gradients may be present which can cause an abrupt drop in electrical resistance readings which would be interpreted as indicating decay when using the recormnended criteria.
P I Morris, D J Dickinson

Gelatin encapsulated fumigants for wood fumigations: Current research status
1985 - IRG/WP 3336
The fumigants chloropicrin (trichloronitromethane) and methylisothiocyanate (MIT) were encapsulated in gelatin as an alternative to liquid fumigant treatments for control of decay fungi in wooden utility poles. Gelatin-encapsulated MIT was stored for over 2 years under dry conditions without significant fumigant leakage. Gelatin encapsulated MIT and chloropicrin were released from capsules when placed in wood above the fiber-saturation point, although capsules were more permeable to MIT than chloropicrin. In field treatments, the addition of small quantities of water along with capsules was sufficient for fumigant release. Encapsulated MIT and chloropicrin treatments effectively reduced decay fungus populations in Douglas-fir utility poles.
A R Zahora, M E Corden, J J Morrell

A review of the current status of the estimation of emissions from preserved wood and their use in the environmental risk assessment of wood preservatives under the Biocidal Products Directive
2005 - IRG/WP 05-50224-7
A review and update of the status of the issues concerning the estimation of emissions from preserved wood (e.g. amendments to the proposed ‘OECD Guidelines’), and the environmental risk assessment of wood preservatives under the Biocidal Products Directive (e.g. compartmental sizes, emissate ecotoxicity testing).
E F Baines

Common Decay Micromorphology “Anomalies” Challenge Current Decay Classification
2006 - IRG/WP 06-10578
Decay micromorphology was studied systematically for diversely preservative treated Pinus radiata and Fagus sylvatica 20 x 20 x 500 mm stakes across 13 in-ground field test sites, during a 6.5 year exposure. New insight into the micromorphology of the early stages of decay enabled new and more detailed interpretation of the mechanism of their formation and suggested that current decay classification lacked sufficient robustness to accommodate common decay types encountered in field-exposed wood. Decay fungi that bypass the decay resistant S3 layer, producing multi-branched hyphae that collectively erode the S2 layer in a fashion similar to simultaneous white rot, forming a “super-cavity” under an overlying lumen wall, were very important in preservative treated beech fibres and pine tracheids. Whilst some of the micromorphology associated with this type of decay has been reported as diffuse type 1 soft rot, its significance has been largely overlooked. Results suggested that several important decay types have been overlooked or misinterpreted because their early defining features are easily masked by later features. This is particularly important for early cavitation decay that forms near or at the S3-S2 interface, and where the overlying lumen wall quickly disintegrates, has been sloughed off during sectioning or has been overlooked in low resolution light microscope micrographs. It is suggested that this has resulted in misinterpretation of cavitation decay types as erosion (Corbett’s type 2, erosion). Use of transmission electron microscopy (TEM) for examining decayed wood has relied heavily on transverse sections or use of high magnification, both of which would mask critical diagnostic features such as intact lumen wall in combination with longitudinally sectioned hyphae both of which are needed for diagnosis.
R Wakeling

Current state of world standardization in the toxicometric methods for testing of wood preservatives
2007 - IRG/WP 07-20354
The paper presents an outline of the history of forming standardized toxicometric methods for testing of wood preservatives in the world during last 100 years. Numerous studies resulted in three main methods which are currently used for official and basis assessment of biocides: - agar-block method in Europe (EN 113); - soil-block method in the USA and Pacific countries (ASTM D 1413); - modified soil-block method in the Russian Federation and the Commonwealth of Independent States (GOST 16712). Further on the paper compares the three methods and presents lines of their global standardization.
J Wazny

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