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The effect of treatment method on CCA efficacy in Corsican pine
1992 - IRG/WP 92-3723
As part of a study into the influence of application method on preservative efficacy Corsican pine (Pinus nigra) samples (50 x 50 x 400 mm³) were treated with a CCA formulation using Bethel, Steam/Bethel or Lowry processes. Full penetration of the preservative at a gross level was confirmed using a copper disclosing reagent. The preservative was allowed to fix and then samples were converted into mini-blocks (30 x 10 x 5 mm³) to produce decay test samples from various locations within the larger samples. After leaching, sets of replicate mini-blocks were exposed to the decay fungi Coniophora puteana FPRL 11E, Coriolus versicolor FPRL 28A, and Chaetomium globosum FPRL S70K. Equivalent sets of leached blocks, were analysed using atomic absorption spectrophotometry to determine preservative concentration and balance. The results of this study have been used to assess the effect of preservative application method on CCA efficacy. They also indicate how treatment method affects the distribution of the active elements of the preservative throughout the treated wood.
P R Newman, R J Murphy

Quantitative determination of Chromium: A comparison of three instruments
1995 - IRG/WP 95-50053
A comparison is made between three instruments for measuring levels of chromium in the leachate of copper-chrome-arsenic (CCA) treated timber. These include an atomic absorption spectrophotometer, an inductively coupled plasma spectrometer and the RQflexâ. The RQflexâ is a new hand-held instrument which measures chromium by dipping a ReflectoquantÒ strip into the leachate and inserting the strip into the RQflexâ. Readings are determined reflectometrically following a reaction between chrome and the Reflectoquantâ strip. It provides an inexpensive and quick technique which is used in this paper to determine the degree of preservative fixation prior to the removal of CCA treated timber from drip pads of wood treatment sites. The results indicate that RQflexâ is a suitable instrument for the rapid assessment of chromium levels in rain wash off from treated timber. A comparison is given of the economics and accuracy of the instruments for measuring chromium.
S Walley, P R S Cobham, P Vinden

Use of biossay to determine CCF and CCB preservative retentions in treated Pinus sylvestris
1984 - IRG/WP 2216
The retention of each a copper/chromium/boron and copper/chromium/fluoride preservative in pressure treated pinepoles was tested by bioassay using Aspergillus niger as test fungus. Small samples of 5 mm³ were taken from various depth of the poles and placed on potato-dextrose agar plates. The inhibition of fungal growth depends on the preservative retention in the cubes and corresponds closely to results obtained by atomic absorption spectrophotometry.
J C Moreschi, H Willeitner

The leaching of copper, chrome and arsenate from CCA-impregnated poles stored for ten years in running water
1978 - IRG/WP 3122
There is no evidence to indicate that the chromium and copper components are leached from the outermost 5 mm of sapwood in poles impregnated with Boliden K33 and Tanalith C and stored in running water for ten years. The arsenic component, however, seems to be leached out during the first few months to an extent of about 20% of the initial amount. The leaching time is dependent on the preservative used.
F G Evans

An interim report on studies of the tolerance by Sphaeroma (Crustacea: Isopoda) of CCA-treated timber
1982 - IRG/WP 491
In Papua New Guinea any untreated timber exposed to seawater close to mangrove stands is liable to be attacked in the intertidal zone by the crustaceans Sphaeroma terebrans or Sphaeroma triste. Even CCA-treated timber is sometimes vulnerable. The mouth-parts of these animals are adapted for boring, but whether wood particles are ingested remains to be resolved. Some limbs of Sphaeroma terebrans appear to be adapted for filter-feeding. In both species a portion of the gut, the hepatopancreatic caeca, contains cells in which large quantities of copper are concentrated. Specimens of Sphaeroma terebrans taken from CCA-treated piles had an average of 35 mg copper per gram dry weight of hepatopancreatic caeca: the corresponding figure for Sphaeroma triste was approximately 7 mg/g. Specimens of Sphaeroma terebrans taken from mangroves had much less copper in them than those from treated wood. No such clear-cut difference was evident in the case of Sphaeroma triste. Analyses of CCA-treated piles infested with Sphaeroma showed that Cu, Cr and As levels were high at the surface, but that levels in the interior of the pile had dropped since installation Further studies of Sphaeroma gut function are in progress.
S M Cragg, J D Icely

CCA fixation experiments. Part 2
1989 - IRG/WP 3505
CCA fixation in wood was measured by both squeezing solution from treated wood that had not been dried and analyzing the solution for copper, chromium and arsenic, as well as using a chromotropic acid test to detect the presence of chromium VI. Both methods provide useful information on the CCA fixation process and illustrate that chromium VI disappears as CCA becomes fixed within wood.
W S McNamara

Assessment of contamination of soil and water at a CCA treatment plant: A demonstration project
1996 - IRG/WP 96-50067
Soil, sludge, dust and water samples were collected at a copper/chromium/arsenic wood preservation plant. Contamination of soil, sludge, dust and surface water with copper, chromium and arsenic was detected. Levels of contamination were sufficiently high to require remediation. Contamination originated from preservative solution dripping from recently treated wood. Migration of contaminants was via surface water run-off; poor housekeeping and operational procedures; forklift movements and wind-blown dust.
P N Durrant, D C R Sinclair, G M Smith

Chemical analysis for TBTN in LOSP-treated wood and preservative fluids
1994 - IRG/WP 94-20027
Tributyltin napthenate (TBTN) is being substituted for tributyltin oxide (TBTO) in LOSP preservative formulations because its lower reactivity/better stability allows co-formulation with synthetic pyrethroids. Better stability may reduce molecular degradation both in-service and during analysis. It was considered necessary to check whether TBTO analysis methods were suitable for use on TBTN treated wood. Five analytical methods for TBTO in wood were applied to TBTN-treated pine sapwood, and evaluated for recovery, accuracy and precision. It was found that treated wood could be oven-dried before analysis, eliminating the need to run parallel moisture content determinations. The best performing method involved extraction of TBTN from oven-dry treated wood with acidified ethanol followed by AAS determination of tin. Performance was checked on freshly-treated and aged material.
D P Wraight, M J Kennedy

Chemical analyses of IRG/COIPM INTERNATIONAL MARINE TEST (to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water) samples
1987 - IRG/WP 4114
Chemical analysis of CCA and CCB treated timber was carried out after exposure at tropical and temperate marine sites. Results indicated that losses of all elements had occurred. In particular, losses of boron were severe. Arsenic and copper were also lost. The chromium components in both formulations was the most dominant metal remaining. The results suggest that chromium modification was important in timber treatments for the marine environment, since there appeared to be little difference in timber protection between the CCA and CCB systems.
L E Leightley

The volatilization of arsenic on burning copper-chrome-arsenic (CCA) treated wood
1978 - IRG/WP 3111
Small scale burning experiments are described involving copper-chrome-arsenic treated wood. Approximately 20 per cent of the arsenic was volatilised when the wood was burned in air but 60 per cent when burned in an oxygen-enriched atmosphere, this increase is attributed to an increase in combustion temperature. Although a small increase in arsenic evolution was found with an increased concentration of CCA in the wood this increase is not considered sufficient to be of any practical importance. The concentration of water-soluble arsenic and chromium in the wood-ash was greater when the experiment was conducted with oxygen-enriched air.
A-J Dobbs, C Grant

Sampling variation in a copper chrome arsenic treated power transmission pole
1990 - IRG/WP 2351
The Queensland Forest Service routinely samples poles treated at all treatment plants throughout the State. Each treatment plant is issued with a Certificate of Registration and the accompanying documents list the different levels of preservative retention required for performance in various service conditions. The posted levels represent the.minimum permissible, and it is to these concentrations of preservative that a piece of treated timber is tested. All samples taken must pass the required level of treatment. Because minimum levels are used, it is important to ensure that any samples taken are representative of the whole piece. A plug sample taken from a pole is 19 mm in diameter by the depth of the sapwood long. The 'analytical zone' is the inner 1/3 of the sapwood band closest to the truewood and the size of the 'analytical zone' varies with the thickness of sapwood. Analyses were carried out on a number of plug samples from a preservative treated power pole, to examine the variation in preservative retention that can occur when samples are taken from different locations along the pole.
J Norton

Leaching and fixation characteristics of chrome-copper-fluoride-zinc (CCFZ) treated wood
1996 - IRG/WP 96-30096
The leaching characteristics of radiata pine sapwood blocks treated with CCFZ were evaluated by the AWPA standard leaching test. The rate of fixation of the preservative components in CCFZ treated radiata pine were also evaluated by quantitative analysis of solution expressed from the treated wood. Both leaching and fixation characteristics of CCFZ were compared with CCA-Type C treated wood samples. The permanence of CCFZ is excellent and comparable to that of CCA-Type C, and the rates of CCFZ fixation were similar to those found for CCA-Type C. These results suggest that CCFZ has a potential as alternative preservative for the replacement of CCA-Type C.
Gyu-Hyeok Kim, Jong-Bum Ra

Fixation and leaching of selected Malaysian tropical hardwood after treated with CCA
2001 - IRG/WP 01-40207
The objective of this study is to investigate the fixation and leaching properties of selected Malaysian tropical hardwood (sentang wood (sapwood and heartwood) and rubberwood) after being treated with copper chrome arsenate (CCA) type-C preservative. The samples were treated with retention level of 0.5%, 2.0% and 5.0%. The samples were leached and the leachate were analyzed by AAS and the amount of remaining CCA elements in the cell (lumen and cell wall) were observed and analyzed using SEM and EDXA. The remaining CCA elements in sample/cell wall indicate the ability of fixation of the samples. Sentang wood could be successfully treated with CCA. Sentang heartwood is harder to treat compared to sentang sapwood and rubberwood. Copper and chromium have higher fixation properties in sentang heartwood compared to sentang sapwood and rubberwood. Arsenic element showed less fixation in sentang heartwood compared to sentang sapwood and rubberwood. Observation and analysis with EDXA showed that the microdistribution of the elements in the cell wall is distributed ununiformly throughout the cell wall and cell lumen.
R Hashim, O Sulaiman, Tan Siew Ching, K Yamamoto

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

Comparative studies on the species effects of wood preservatives
1989 - IRG/WP 3521
For the examination of the resistance against fungal attack, wood blocks of 3 softwood species were treated with CCA (type 3), CFK, AAC and IF-1000 independently. The wood blocks were exposed to the fungal decay with Tyromyces palustris. The degradation of the wood blocks treated with these preservatives was quite widely different among wood species examined in this study. Hem-fir treated with CCA and radiata pine treated with CFK showed less durability than the other species and other preservatives. In the case of Cryptomeria japonica, all preservatives tested gave good results. The micromorphological distribution of preservatives in cell walls was investigated with the wavelength dispersive X-ray spectrometry. The X-ray photoelectron spectroscopy was applyed for the investigation on the possibility of conversion reactions with preservatives in impregnated wood. The interaction of extractives with preservatives was examined using a conventional bioassay method for evaluations of the efficacy of wood preservatives against fungi. The concentration of Cr in the CCA treated wood was 1.5-1.6 times higher in the ray parenchyma cell walls than in tracheid walls in every wood species examined. The oxidation of wood occur during the treatments with CCA and CFK, however, there were not conspicious differences in the degree of oxidation among wood species. Although the hot water extractives themselves accelerated the mycelial growth, only the extractives of hem-fir reduced the efficacy of CCA.
K Yamamoto, S Matsuoka

A laboratory study on effect of coating materials on leaching of copper from CCA treated wood
2001 - IRG/WP 01-50176
Components of CCA preservatives can leach into surrounding soil and water and have some effect on germination and growth of some plants. In this report, the effect of coating materials in reducing chemical concentration in the leachate were evaluated. Rubber wood blocks (Hevea brasiliensis) treated with CCA were fixed at room temperature at high humidity. After air dried, they were painted with coating materials, then followed by leaching procedure. The concentration of copper in the leachate was analysed by atomic absorption spectrophotometry. The results showed that coating materials could reduced the concentration of copper in leaching water. In addition, the resistance of treated wood against destroying fungi was studied. After painted with coating materials, wood specimens were exposed to fungi for the periods of time and results were discussed.
A Veenin, T Veenin

Surface accumulation of copper on CCA-impregnated Pinus patula stakes during marine preservative trials in the southern hemisphere
1992 - IRG/WP 92-4181
Pinus patula stakes treated with CCA to target retentions of 30 kg/m³ salts were exposed to sea water in marine and estuarine ecosystems off the coast of Southern Africa for two years. Samples were then analysed for copper and arsenic. Analysis of samples from the marine ecosystem showed (IRG/WP/4167) that arsenic was longitudinally and transversely leached from the wood, whereas the copper was redistributed to the surfaces of the wood. Recent analyses have now confirmed that similar trends of copper mobility occurred in Pinus patula exposed to the estuarine ecosystem, i.e., copper levels within the wood decreased while the levels of the exterior zones of the wood increased correspondingly.
G D Shelver, C D McQuaid, M Tarin, A A W Baecker

Field evaluation of CCA movement in sap-displaced copper chrome arsenic treated softwood poles
1989 - IRG/WP 3539
Commercial sap-displaced UK grown Scots and Corsican pine, and Sitka and Norway spruce poles were exposed in a field site at Dundee, Scotland and radial distribution profiles of CCA monitored prior to implantation and after subsequent field exposure. Results show that groundline levels of all preservative elements were higher after 1 and 2 years field exposure compared with those recorded prior to pole implantation. In addition, chemical analyses of the soils at the groundline regions of the poles showed that raised metal levels were detectable. Some of the implications of the results are discussed.
S D Hainey, G M Smith, A Bruce, P D Evans, B King, H J Staines

Determination of boron levels in solution and in treated wood
1994 - IRG/WP 94-20041
Four methods of measuring boron levels in solutions were investigated. The methods compared included the azomethine-H method which is commonly used in soils and plant tissues, the methods outlined in the Australian Standard AS 1605 (1974) and in Wilson (1958), and the atomic absorption spectrophotometry method. Defect-free radiata pine (Pinus radiata D. Don) sapwood and wood flakes were treated to different percentage boric acid equivalent (%BAE). A slightly acidic aqueous medium was used to extract boron from the samples. Extracts were analysed using the azomethine-H and carmine methods. The recovery and coefficient of variation were calculated and discussed. Results confirmed that all methods can be used for measuring boron in solution and wood samples at the range of%BAE investigated. However, the azomethine-H method was found not only to be the simplest and quickest but the most accurate method. It was also found that wood extractives in the wood did not affect the results.
F J Romero, P Vinden, P Kho

Premature failure of CCA treated vineyard posts from brown rot
1993 - IRG/WP 93-10016
A survey of CCA (AWPA Type C) treated posts used as grape vine trellis supports, to determine the extent and type of decay was carried out at a terraced vineyard in the Hawkes Bay region of the North Island of New Zealand. Of 357 posts examined out of a total of 970 in the vineyard, 47% had moderate to severe decay or had failed, 20% had established decay, 10% had a trace of decay and 23% had no sign of decay. The posts were less than three years old at the time of the survey and it was predicted that the average life of the posts would be 5 years. Atomic absorption spectroscopy showed that the average above and below ground CCA retention for 13 failed posts were 17.32 and 14.80 kg/m³ of salt respecitively. Light and transmission electron microscopy showed that brown rot was the only cause of decay. The rapid rate of decay was in part attributed to a high inoculum potential for brown rot in the soil caused by the presence of a large volume of decaying wood. It seemed likely that this high inoculum potential conferred a high degree of tolerance to CCA by the brown rot fungus or fungi. Leucogyrophana was consistently isolated from soil but certain observations relating to the morphology of fungal hyphae and the presence of Chlamydospores in decayed wood suggested that another fungus may have been responsible.
R N Wakeling, A P Singh

Susceptibility of antisapstain fungicides to rain wash-off
1994 - IRG/WP 94-30046
Results of trials using miniature timber packets and simulated rain wash-off are described. Six fungicidal actives in five commercial antisapstain formulations were involved, and a clear influence of rainfall timing after antisapstain treatment was demonstrated. Differences between actives and formulations were most marked where water-spray was applied in the first hour after treatment, though even when applied after a 48 hour delay there were up to ten-fold differences in the percentages mobilised. Possible mechanisms of fixation are discussed in relation to known formulation properties. Results from a full scale trial at a sawmill are also given, and comparison made with the small-scale packet experiments. It is concluded that the results were very similar. The work is extrapolated to the 'real-life' sawmill situation, and conclusions drawn as to the likely results of heavy rain exposure at different times after fungicidal treatment of timber.
R N Wakeling, D J Cross, D R Eden, P N Maynard

Leaching from CCA-treated wood submerged in seawater: Effect of high loadings, and a comparison between laboratory and marine conditions
1996 - IRG/WP 96-50080
This study of leaching examined the following variables: CCA loading; marine versus laboratory exposure and length of submergence. Blocks of Pinus sylvestris were treated to a range of nominal retentions from 15 to 50 kg/m³. Each block was then divided into three cubes and all transverse faces were sealed. All cubes were allowed to fix at ambient temperature for a minimum of one week. One set of end cubes were submerged at Sagres, Portugal; the other end cubes were submerged in seawater in a laboratory system to provide a comparison of marine and laboratory leaching. Marine blocks were removed at periods of 1, 6, 12 and 18 months. Laboratory blocks were removed at 1, 2, 4 and 6 months. The middle cube was analysed using atomic absorption spectroscopy to provide the initial preservative loading for each block. After the submergence period end cubes were analysed to determine the amount of preservative remaining. Results showed that there was a time-related decrease in the flux of all metals from the cubes exposed in the laboratory. Leaching of chromium and arsenic was negligible in the marine environment, but copper losses showed a similar time-related pattern of flux, though it was lower than that observed in the laboratory. Measurement of the metals in the laboratory seawater confirmed that copper and arsenic were leached in excess of chromium.
R M Albuquerque, S M Cragg, J D Icely

Fouling organisms as indicators of the environmental impact of marine preservative-treated wood
1995 - IRG/WP 95-50063
This study evaluates the use of fouling organisms (epibiota) to assess the environmental impact of preservative treated wood. This paper presents initial findings from treated panels exposed for 6 months at Sagres, Algarve, Portugal. Panels were treated with CCA, two copper-containing quaternary ammonium (ACQ) formulations and creosote, with nominal retentions from 10 to 40 kg/m³ (creosote 25 pcf). The presence of an abundant, diverse and healthy epibiotic community growing on treated wood was used as an indication that the preservative treatment had a relatively low impact on its immediate environment. Algae and mussels (Mytilus galloprovincialis) were the dominant members of the fouling community which developed on all preservative treated wood panels. The biomass (dry weight of organisms) and species diversity of epibiota scraped from the surface of preservative treated wood panels showed the following order CCA > Creosote > ACQ 1:1 > ACQ 2:1. No difference was detected concerning the shell dimension of mussels between treatments, but mussel biomass was much lower on ACQ-treated test samples, indicating that mussel settlement was affected by ACQ treatment, but growth was not. Algal biomass was highest on creosotetreated panels, with biomass on other panels fitting the following sequence: Creosote > CCA > ACQ 1:1 > ACQ 2:1. Copper, chromium and arsenic contents of algae were determined by atomic absorption spectroscopy (AAS). Elevated levels of Cu, Cr and As were found in the macroalgal mat from CCA-treated panels. These levels showed significant positive linear regressions with panel preservative retention levels. Higher levels of copper were found in macroalgal mats from ACQ-treated wood, but showed no linear relationship to panel preservative loadings. Copper levels did not exceed 9 ppm in algal tissue, chromium and arsenic levels were below 1 ppm.
R M Albuquerque, S M Cragg

Estimation of the impregnation degree of pine wood by the distribution analysis of active ions concentration in the cross-section
1999 - IRG/WP 99-20174
Samples in the form of pine wood rollers of diversified moisture content of ca. 50, 28 and 12% were impregnated with a water solution of the mixture type CCB with the use of the full-cell process. Moisture content was determined in individual layers from the girth to the pith. In the same way the concentrations of copper and chromium ions with the use of the spectrophotometric method and recalculated to the total dry mass of the preservative. Simultaneously, there was performed biological test according to EN 113 for the investigated mixture and different concentrations: 0,1; 0,16; 0,25; 0,4; 0,63; 1,0; 1,6; 2,5. The obtained fungicidal value let to determine the depth of biological resistance of impregnated wood within the impregnated zone.
K Lutomski, B Mazela

A technical note on the limitations of atomic absorption spectrophotometric analysis of copper/chrome/arsenic solutions according to BS 4072 (1974) and BS 5666: Part 3 (1979)
1988 - IRG/WP 2320
British Standards BS 4072 (1974) and BS 5666: Part 3 (1979) detail an atomic absorption spectrophotometric method for the quantitative determination of copper, chrome and arsenic in both preservative solutions and treated timber. Use of this technique during a research programme at Aberdeen has highlighted some potential inaccuracies with this method if these standard specifications are adhered to rigidly. These involve the standards specifying the production of inappropriate concentrations of solutions for calibration purposes and "unknowns" for analysis. Possible methods of avoiding these problems are discussed.
A J Pendlebury, J A Petty

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