Your search resulted in 41 documents. Displaying 25 entries per page.
World survey on the status of pollution control in the field of wood preservation
1976 - IRG/WP 369
In 1974 the IRG/WP-Secretariat distributed a "Questionnaire on the state of pollution control in the field of wood preservation" which was prepared by the author. The questionnaire consisted of two parts. Part A asked "General questions" on - the position of wood preservation in the respective country - the use of preservatives - the type of application of wood preservatives in different fields - the state of pollution control. Additional details to the questions of Part A were requested in Part B. This part also included questions on - the special work on pollution control in wood preservation in the respective country - the use of residues and old timber. A preliminary report on the answers to the questionnaire was given in IRG-Document 56 to the plenary meeting at Vienna, Austria in June 1974. Since then, all questionnaires, including also those received after the Vienna-meeting, were evaluated in detail. Mistakes made during the rough evaluation in 1974 have been corrected. Therefore certain differences may occur between the preliminary report and the present one. Further more the answers to Part A and Part B of the questionnaire have been combined in the tables of this report.
Aspects of diffusion of boron through wood
1984 - IRG/WP 3298
Boron compounds have been shown to be toxic to a wide range of wood destroying insects and fungi. They are cheap, have low mammalian toxicity and their application in the treatment of wood does not demand specialized equipment. These attributes make them specially attractive to developing countries. Currently, however, little is known about the mechanism of diffusion of boron through wood. Effective treatment with boron preservatives requires good understanding of how the preservatives diffuse through wood. This paper presents a research proposal with the overall objective of determining the relative importance of structural wood components in determining diffusion rates.
Health aspects concerning the use of bifluorides in wood
1981 - IRG/WP 3173
An attempt has been made to find a correlation between the quantities F¯ and HF present among other ions in an 'Improsol' solution consisting of NH4F.HF and KF.HF, the quantity absorbed by the wood from this after immersion and the toxicological effects of this treated wood when it is used in rooms destined for the residence of people or animals or for the storage of foodstuffs.
H F M Nijman
Aspects of the biology of the wood-boring weevil Pselactus spadix herbst
1997 - IRG/WP 97-10221
The external morphology of the adult and larval digestive tract of the wood boring weevil Pselactus spadix has been reported for the first time. An examination of adult gut ultrastructure showed that the foregut was adapted for the wood boring habit with the presence of chitinous setae, grinding plates and sieve plates. The adult midgut bore eight caecae and numerous palpii. Spherical yeast-like micro-organisms were observed throughout the foregut and midgut. Adults demonstrated sexual dimorphism in body capsule and rostrum dimensions. The study also demonstrated this weevil to be incapable of flight.
G Cooper, A J Pitman, G S Sawyer
Programme section 5, Environmental aspects
1997 - IRG/WP 97-50099
Programme section 5, Environmental aspects
1996 - IRG/WP 96-50077
Report an some aspects of forest and the timber preservation in Fiji 1999
2000 - IRG/WP 00-40189
This report is divided in two sections. One is the general description of some aspects of the Forest indicating timber availability in Fiji. The other Section is an "Status of Timber Preservation in Fiji in 1999".
S D Kumar
Supplement to Document No: IRG/WP/56. Health and safety aspects of the use of wood preservatives
1975 - IRG/WP 356
Draft economic plan for the IRG for the period 1993-1997
1993 - IRG/WP 93-60004
Some aspects of laboratory and field testing methods of antitermite wood preservatives
1973 - IRG/WP 235
Various methods for laboratory testing of antitermite activity of wood preservatives are described. The results of simultaneous tests of three water-borne preservatives, according to the various methods are discussed, and comparison is made with results of field tests on the same three preservatives, showing a fairly good accordance between laboratory results and field results.
Programme Section 5 Environmental aspects
1999 - IRG/WP 99-50138
An introduction to environmental aspects of groundwater arsenic and CCA treated wood poles in Bangladesh
1997 - IRG/WP 97-50081
The environment comprises biosphere, lithosphere, atmosphere and hydrosphere. Therefore, environmental science is a multi-disciplinary study, includes life sciences, physical sciences, chemical sciences, geology, geography, meteorology, forestry, agriculture, soil science, hydrology, ecology, public health, engineering etc. Tremendous industrial and mining activities, deforestation and population explosion are threatening the very existence of life on earth.Groundwater is used for irrigation, drinking and other domestic purposes where other sources of water are not plenty. Groundwater contain different metals resulting from soluble minerals, deposited in ground during its origin. Thus concentration of metals in surface soils and water are increased day by day by lifting of groundwater. Surface soils and water also receive metals from industries and mines and as a result of multipurpose use of products from those. Deforestation is controlled by plantation and preservation of forest products by different wood preservatives. Recently groundwater in some underground rocks of Tertiary and Quarternary age in Bangladesh is very often known to contain arsenic (As) above permissible limits . On the other hand chromated copper arsenate (CCA) impregnated wooden poles has been used for rural electrification in Bangladesh since 1979. It is an attempt to find out through research and review of literatures that whether the groundwater As is contaminatable from As used in wood poles and whether the components of CCA cause environmental problems. Possible way of purification of arsenic containing groundwater for drinking have been suggested.
A K Lahiry
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.
Health and safety aspects of the use of wood preservatives. Preliminary evaluation of the answers to the IRG-Questionnaire on the state of pollution control in the field of wood preservation
1974 - IRG/WP 56
This preliminary evaluation of the answers to the IRG/WP-Questionnaire only gives a general survey on those questionnaires, which the author received until June 13, 1974. Details, such as correlations between importance of wood preservation and pollution control, could not be considered due to lack of time. For the same reason it was not possible so far, to evaluate the additional remarks given in seperate letters. In the case, where several questionnaires have been returned for one country, the respective answers were compared. If answers differed within one country, those were considered, which seemed to be most applicable. Obvious errors were omitted.
Ultrastructural aspects of bacterial attacks on an archaeological wood
1993 - IRG/WP 93-10007
Transmission electron microscopy of wood from a Chinese ship submerged in the mud for over 900 years showed bacteria to be the main factor for its deterioration. The micromorphology of degraded wood cell walls was similar to that observed during the attacks of wood by erosion bacteria. Other bacterial forms, previously considered lo be scavenging bacteria, were also abundant in degraded areas of the wall. The observations on the breakdown of the waterlogged archaeological wood are discussed in context with the available information on bacterial degradation of wood under near-anaerobic conditions.
Yoon Soo Kim, A P Singh
Health hazards and environmental aspects when using Cu-HDO-containing wood preservatives in vacuum pressure plants
1993 - IRG/WP 93-50001-11
Apart from the biological efficacy of wood preservatives, the health and environmental aspects concerning the utilisation of wood preservatives, the use of treated timber and the disposal of impregnated wood are of high significance today. Therefore, information on a possible aerial concentration of wood preservatives, on the mobility of active substances in soil leached from treated timber in service and on the composition and toxicity of thermal decomposition gases releasing on combustion of impregnated wood, are of absolutely fundamental interest. Measuring procedures relevant for the practical application will be presented, and the results concerning the utilisation of Cu-HDO-containing wood preservatives will be described. With the proper use of Cu-HDO-containing wood preservatives, the aerial concentration at workplace falls distinctly below the maximum permissible limit. If vacuum pressure treated timber is used properly, no active substances will seep into the ground water as a result of the leaching process of impregnated wood in service. The composition measured and the acute toxicity of the thermal decomposition gases released on combustion of impregnated wood may axtually be compared to those of untreated timber.
W Hettler, S Breyne, M Maier
Health and safety aspects of the use of wood preservatives in Sweden
1977 - IRG/WP 396
The Act on products Hazardous to Health and to the Environment (Swedish Code of Statutes SFS 1973:329) came into force on 1st July 1973. The Act cancelled and superseded the Poison Act, the Pesticides Act and the PCB Act from 1962, 1962 and 1971 respectively. Regulations for the implementation of the Act are contained in the Ordinance on Products Hazardous to Health and to the Environment (SFS 1973:334) and also in an Amendment of the Ordinance (SFS 1973:1050). A comprehensive summary of the Act and the Ordinance prepared in common by the Swedish Ministries of Agriculture and Foreign Affairs has been deposited in the IRG/WP Secretariat. Much of the information given below as regards the Act is derived from this booklet.
Kiln drying of CCA-treated wood - Some safety and environmental considerations
1987 - IRG/WP 3443
Vapours and condensate from a condenser kiln in which CCA-treated wood was being dried have been collected and analysed. The concentrations of arsenic, copper and chromium found in the vapours from the drying process were well below Swedish threshold limit values. The contents of arsenic and chromium were also low in the condensate, although the copper content was fairly high. The latter result was probably because the low pH of the condensate caused some copper to be leached out from the copper pipes of the dehumidifier device. If precautionary measures are taken when condenser type kilns are constructed in order to prevent the leaching of heavy metals by low pH condensate liquors, there would seem to be no safety or environmental problems with this type of kiln.
J Jermer, B Lundberg
Present status and potentiality of the economic utilization of the sawmill residue and wastage in Bangladesh
2004 - IRG/WP 04-50211
This study has been carried out to obtain a clear picture about the current status of utilization of sawmill residue and wastage. In order to accomplish the study a random survey has been conducted in 27 sawmills of Khulna District and in 10 sawmills of Jessore District. Most of sawmills in these area run at a very primitive level compared to modern technology. Species used for conversion mainly depends on the demand and availability of logs in the surrounding areas of sawmills. In Khulna and its surrounding area the daily average consumption of log is about 104.86 cft., per sawmill. Daily average production is about 62.39 cft., and 42.47 cft. Wood is wasted as sawdust, edging/trimming, slab and in other ways. The percentage of production and residue is about 59.5% and 40.5% of the total consumption of logs in the sawmills respectively and among the total sawmilling residue, edging/trimming, sawdust, slab and others constitute about 20.73%, 12%, 4.22% and 3.55% respectively. Here it has also been attempted to estimate the approximate amount of wood wasted in 4,800 sawmills of Bangladesh. About 3.34 million tones per year of wood waste is produced during conversion in which edgings/trimmings, sawdust, slabs of different inferior sizes and others are about 1.71, 0.99, 0.35 and 0.29 million tones per year respectively. The most amount of sawmill residue is being used as fuel for cooking. About 100% of edging/trimming residue is used as fuel and 60% slab is used as fuel and another 40% is used for box making. Among the total produced sawdust about 70% is used as fuel and 30% is used as other purposes like in poultry farms, as water absorbing material, in ice factories etc. But this huge amount of sawmill residue can be used for manufacturing various value-added products like particleboard.
M A Islam, M S Rahman, A K M A Bosunia, A K Lahiry
Biochemical aspects of white-rot and brown-rot decay
1987 - IRG/WP 1319
This paper presents an overview of the decomposition of wood by white- and brown-rot fungi - the most important and potent of known wood-decay fungi. These organisms are unique among cellulose destroyers because of their strong capability to enzymatically degrade lignified material. Special emphasis is given to the following aspects of wood decomposition by white- and brown-rot fungi: (1) effects on the chemical and physical properties of wood, (2) method of invasion and ultrastructural modification of wood, (3) nature and activities of extracellular degrating enzymes, (4) relationship of ultrastructural changes to the degradative enzyme systems, and (5) unique physiological features of the fungi that can be used to control decay.
T L Highley
Economical analysis of the chemicals used on remediation copper, chromium and arsenic from out of service CCA-treated utility poles in Turkey
2004 - IRG/WP 04-50217
There are 20.7 million hectare forested area in Turkey. However, the wood products supplies do not meet demand. One of the wooden products is the utility poles. In Turkey, impregnation of utility poles has been started since 1960's and 5 million utility poles have been used until today since then. Although life time of the utility poles may vary depending on climatic conditions, average service time of utility poles used in Turkey is about 25 years. Therefore, it is estimated that each year 200.000 m3 utility poles are out-of-service and they need to be replaced. In recent years, because of the unwanted effects of out-of-service CCA treated utility poles either during their storage or being recycled, there is a urgent needs to find a way removing Copper, Chrome and Arsenic from out-of-service CCA treated utility poles. For this purpose, many scientists have been studying on remediation of CCA treated wood. In this study, oleic acid, chromotropic acid and citric acid were used to remove Cu, Cr and Ar from CCA treated wood samples. The objective of this study is to determine the chemical that provides the maximum Cu, Cr and Ar removal from CCA treated wood as well as the cost effective one.
E D Gezer, D Toksoy, Ü C Yildiz
Aspects of leaching
1976 - IRG/WP 267
With respect to Document No: IRG/WP/246, and the recommendation that an economic leaching test can be based on a non-changing volume of water (500 ml/block), I would like to relate our experiences with this suggestion. Following 14 days of continuous immersion in de-ionized water it was found that blocks treated with moderate and above concentrations of a preservative gave no problems, but those blocks either having low chemical treatments or none (controls) produced a very healthy growth of slimy fungi and bacteria. Obviously these micro-organisms could be affecting the wood structure, should you wish to subsequently decay the blocks for biological toxicity evaluation. Also the micro-organisms could be degrading or otherwise modifying the preservative under evaluation. Under the old methods of "beaker leaching", with the water being changed daily, the growth of micro-organisms does not appear to be a problem. Any sugars leaching out into the water are removed within 24 hours and therefore the environment does not support their growth. The proposed method may be acceptable for leaching blocks containing a high retention of preservative (as reported in the paper), but as a method generally applicable to a concentration range of retentions, it does not seem to be acceptable. Obviously toxic agents could be added to the leaching water to prevent the growth of such micro-organisms, but this would have unpredictable effects on the wood-preservative-fungus complex under examination. I feel that this situation should be brought to the attention of the members of the IRG Working Group, since a non-biologist might not be aware of what has happened to his test and therefore present erroneous results.
R S Smith
Aspects of the fungal degradation of quaternary ammonium compounds in liquid culture
1997 - IRG/WP 97-30160
Didecyldimethylammonium chloride (DDAC) is a quaternary ammonium compound (QAC) that has found use as an anti-sapstain preservative for the transportation of softwood lumber from Canada to overseas markets. However, its use is limited by the knowledge that certain mould fungi seem capable of degrading it. The aim of this research was to gain knowledge about the fungal degradation of DDAC. The effects of Verticillium bulbillosum - a demonstrated QAC-degrading mould - on DDAC within a defined liquid culture were studied. Interactions between the liquid medium and DDAC; the degree of fungal tolerance under varying conditions; and rate of degradation paralleled with fungal growth were examined.
J W Dubois, J N R Ruddick
A preliminary assessment of the costs of termite activity in Australia: A discussion paper
1983 - IRG/WP 1207
A preliminary assessment has been made of the economic importance of termite activity in Australia and this paper is intended to serve as a starting point in discussing this topic. Damage to timber in service represents their greatest area of economic importance in urban and rural environments. Costs resulting from termite activity include timber replacements in buildings, railway sleepers, transmission poles, termite surveys, insecticides and wood preservatives. Indirect costs are briefly discussed, as are the beneficial roles of termites in our environment.
J R J French