Your search resulted in 183 documents. Displaying 25 entries per page.
Proposed methodology for the assessment of safety indexes
1990 - IRG/WP 3562
Safety Indexes (SI)s are developped on the same concept as Efficacy Indexes (EI)s: EIs are retentions of wood preservatives (percentages of the critical values "efficacy") which are presumed efficient for a given biological class of risk. In the same way, SIs are retentions of wood preservatives (percentages of the critical values "safety") which are taken as acceptable for human health and the ge...
G Ozanne
Chromium on the surface of CCA-treated wood
1978 - IRG/WP 386
Chromium in solutions of CCA preservatives is predominantly in the hexavalent state (Cr VI). It is well known that Cr VI is associated with dermatitis and skin ulceration in workers handling chromium containing products and processes. When reduced to the trivalent state, however, chromium is considerably safer. An essential part, therefore, of safety procedures in any chromium - using industry is ...
C R Coggins, P Hiscocks
Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 6: The length of the primary precipitation period
1975 - IRG/WP 359
The end of the primary precipitation fixation period of CCA preservatives coincides with the first peak in pH versus time. This offers a simple way of estimating the duration of the period. The duration is determined by a number of factors and their interactions, the most important of which are: wood species (anatomy, natural pH, accessibility of reducing agents), preservative type, preservative c...
S-E Dahlgren
Some practical implications from recent research on the fixation of CCA preservatives
1975 - IRG/WP 358
The mechanism of fixation of CCA preservatives is briefly described. If the temperature is increased during the primary fixation period, the formation of intermediate fixation compounds is less extensive. The length of the primary fixation period is of practical interest. It is determined by preservative composition and concentration, temperature and wood species. Diagrams are given for Pinus sylv...
S-E Dahlgren
Comparative Laboratory Leaching Test Methods to Study Post-Treatment Storage Period Impacts on CCA Leachability and Fixation in Treated Kempas (Koompassia malaccensis) Heartwood
2007 - IRG/WP 07-20376
Three laboratory leaching test methods were compared to determine the effects of different post-treatment storage fixation periods on leachability/fixation of CCA components from treated kempas (Koompassia malaccensis) permeable heartwood. End-sealed test wood blocks of permeable were treated with CCA to target retention of 5.6 kg/m3, immediately stored to fix at ambient conditions for 0 and 48 ho...
A H H Wong, H C Lai
Influence of different fixation and ageing procedures on the leaching behaviour of copper from selected wood preservatives in laboratory trials
2003 - IRG/WP 03-20264
The paper focuses on the role of different parameters, such as fixation, sample size, wood species, and leaching in internationally standardized ageing procedures for wood preservatives from Europe, Japan and the United States.
The leaching protocols used were EN 84, JIS K 1571 and AWPA E11 protocols. The wood species were Scots pine, Sugi and Southern Yellow Pine respectively. Three types of com...
J Habicht, D Häntzschel, J Wittenzellner
Application of radio frequency heating to accelerate fixation of CCA in treated round-wood
1999 - IRG/WP 99-40133
The potential of radio frequency heating to accelerate the fixation of chromated copper arsenate (CCA) in treated round-wood was assessed. Pre-dried Douglas-fir and western red cedar round-wood sections were pressure treated with CCA in a pilot plant retort, after which they were placed individually in a pilot radio frequency (RF) chamber. Based upon the color reaction of chromotropic acid with he...
Fang Fang, J N R Ruddick
Problems of fixation of CCA-preservatives in palm-wood
1985 - IRG/WP 3338
Palm-wood may be used for posts and poles where it needs proper treatment for long time use. Based on observations by W. Killmann on low CCA-fixation in palm-wood, samples of Jubaea-palm grown in a Greenhouse at Hamburg, have been treated in two different series with a 4% solution of CCA-type B. After 1-16 weeks of storage the blocks were split into sticks of 1-2 mm² and leached. In all series 50...
H Willeitner, K Brandt
Radical changes in the requirements for more safe pressure impregnation in the Nordic countries in 1988
1990 - IRG/WP 3581
After introduction of quality control schemes and standards in the Nordic countries during the seventies, the first radical change of the standards and practice of work took place after pressure from the labor unions and authorities in 1988 and 1989 in Denmark and in Sweden. A new class of preservation with less retention for out of ground contact use was introduced, fixation times were prolonged ...
B Moldrup
Accelerated fixation of CCA in borak bamboo (Bambusa balcooa Roxb.) of Bangladesh
2001 - IRG/WP 01-40193
CCA-C fixation study on impregnated (6% CCA solution), then boiled, oven-dried, normal, air-dried and steamed bamboo slices of air-dried borak bamboo (Bambusa balocca Roxb) of Bangladesh, revealed almost complete fixation in steamed (accelerated fixation) and air-dried (3 weeks, slow fixation) bamboo slices compared to moderate to slow fixation in boiled, oven-dried, normal and 24h air-dried slice...
A K Lahiry
Draft economic plan for the IRG for the period 1993-1997
1993 - IRG/WP 93-60004
P-E Dickèr
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
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 w...
L N Santhakumaran
Assessment of losses of wood preservatives from treated wood by leaching into the environment
1993 - IRG/WP 93-50001-13
Wood preservative chemicals may be lost from treated timber by leaching into water or soil. The degree to which this might occur and its effect on the environment is difficult to assess quantitatively due to the absence of appropriate test methods. This paper describes work to assess test methodology capable of allowing the rates of loss of wood preservative from treated timber to be quantified. T...
R J Orsler, G E Holland
nvestigation of anomalous fixation and leaching of CCA-treated red maple
2004 - IRG/WP 04-30341
The fixation of CCA-C preservative was investigated in red maple sawdust (Acer rubrum L.) at target retentions of 4.0, 6.4, 9.6 and 30.0 kg/m3. The effect of water-soluble extractives on the course of fixation was evaluated comparing the non-extracted with pre-extracted samples treated to 6.4 and 30 kg/m3. Leaching of the CCA components was monitored after complete fixation for all retentions. Fix...
S Radivojevic, P A Cooper
A simple leaching procedure for in-plant monitoring of CCA fixation
1993 - IRG/WP 93-30023
A simple leaching test is described to quantitatively estimate the extent of fixation of chromated copper arsenate (CCA) preservative treated wood products. It is based on the reaction between diphenylcarbazide and unreacted hexavalent chromium leached from borings taken from treated wood during the fixation process. The test requires about 20 minutes to complete and can be set up in a treating pl...
P A Cooper, Y T Ung
IRG Foundation Fund Report for the period 1 January to 31 December 1988
1989 - IRG/WP 5344
B Henningsson, H Friis-Hansen
A short note on fungal decay in K33-treated poles
1982 - IRG/WP 1169
Soft rot cavities and erosion of the lumen have been found in K33-treated Pinus sylvestris poles from the years 1956-66 by microscopic studies. Poor treatment quality has been proved for some of these poles. The microscopy showed an unusual pattern of attack, and pre-treatment decay is suspected but not yet proved. Sounding the poles and using the Pilodyn indicated decay, but poking did not. Quant...
H Friis-Hansen
Multiple-Phase Pressure (MPP) Process: One-stage CCA treatment and accelerated fixation process. 5. Treatment of Sitka spruce and Scots pine
1999 - IRG/WP 99-40136
The suitability of the MPP Process for CCA treatment and accelerated fixation of species other than Radiata pine was assessed by pilot plant trials on UK-grown Sitka spruce (Picea sitchensis) and Scots pine (Pinus sylvestris). Pressure and vacuum kickbacks of spruce (14 l/m3) and Scots' pine (122 l/m3) were both substantially lower than that generated during treatment of radiata pine (369...
M E Hedley, K Nasheri, G Durbin
The influence of previous anti-blue-stain preservative treatments on the fixation of CC in spruce
1997 - IRG/WP 97-30134
Freshly cut and kiln dried spruce boards were treated with 4 different anti-blue stain preservatives (ABP). After a period of 10 days allowing the samples to dry and fixate, the samples were treated with CC (chromium, copper formulation) using a vacuum pressure cycle. After impregnation the wood was steam fixed. A submersion leaching test showed differences in the leachable quantity of copper and ...
M Van der Zee, W J Homan
A fixation model, based on the temperature dependence of CCA-C fixation
2000 - IRG/WP 00-40163
A model was prepared for the fixation of 1% CCA-C in red pine that allows the prediction of extent of fixation based on the temperature history of the treated wood following pressure treatment. The reaction kinetics of the rapid initial reaction and the slower main reaction were characterized using the Van t'Hoff equation. The initial reaction could be represented by a 10th order chemical...
P A Cooper, K M F Kazi, Jianbin Chen, Y T Ung
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 labora...
H M Barnes, D P Kamdem, M H Freeman
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
CCA fixation experiments. Part 1
1989 - IRG/WP 3504
A method of squeezing solution from CCA treated wood that has not been dried at various times after treatment appears to be useful in following the fixation of CCA in wood. Experiments confirm that temperature governs the rate of fixation....
W S McNamara
Rapid leaching test
1991 - IRG/WP 2367
An accelerated test which is suitable for measuring the extent of metal fixation in both chromium and non chromium containing preservatives is described....
J A Cornfield, M Bacon, A Lyman, C Waldie, M R Gayles