Your search resulted in 14 documents.
Observations on the colonization of freshly-felled timber treated with prophylactic chemicals by mould and sapstain fungi
1989 - IRG/WP 1394
Field tests using freshly felled pine sapwood were set up to determine the effectiveness of a range of antisapstain compounds and to study the problems of colonization by mould and sapstain fungi. Differences were recorded both in the overall performance of the compounds and also their selectivity in controlling specific fungal types. These results were found to be useful in gaining a better under...
G R Williams, D A Lewis
Report of field test results for dichloro-n-octyl-isothiazolone: A potential new wood preservative
1988 - IRG/WP 3495
In a previous report (IRG/WP/3306) we presented preliminary laboratory test results on 4,5-dichloro-2-n-octyl-4-isothiazolone (RH 287). Laboratory data indicated toxic threshold values for RH 287 ranging from 0.37 to 0.50 kg/m³. In this report we present field test results on an IRG L-joint test and an in-ground stake test for RH 287, pentachlorophenol and biocide free test units. (a) L-joint tes...
D E Greenley, B M Hegarty
Antifungal mechanism of dichloro-N-octylisothiazolone
1998 - IRG/WP 98-30183
4,5-dichloro-N-octylisothiazolin-3-one (DCOI) is a member of the isothiazolone class of preservatives, whose antimicrobial mechanism of action has been intensively studied over the last decade. DCOI has also been intensively studied for use in wood preservation. The isothiazolones are electrophilic molecules that rapidly react with thiol groups to form covalently bonded isothiazolone-thiol adducts. This ability to bond with thiol groups is crucial to their ability to act as preservatives.
Thiol groups are present in proteins as part of the amino acid cysteine, where they play an important role in maintaining protein structure and function. A number of enzymes have thiol groups at the site where the enzyme function is performed, and these thiol groups may participate in the enzyme reaction. If the isothiazolone reacts with this thiol group, the activity of the enzyme is inhibited. Our studies have shown that there are several enzymes in the Krebs cycle that are inhibited by isothiazolones and these enzymes are required to generate energy and perform many biosynthetic functions. Reflective of this, DCOI has been shown to be a rapid inhibitor of cellular respiration, causing the cell to cease consuming oxygen almost immediately upon contact with DCOI. The multiplicity of targets and their central importance to the metabolism of the cell, as well as the fact that all microbes use at least parts of the Krebs cycle, can be related to the low use levels and broad spectrum of activity of DCOI.
The antimicrobial mechanism of DCOI results in a potent rapid-acting preservative with a broad spectrum of antifungal and antibacterial activity that is effective at low levels.
J S Chapman, M A Diehl, K B Fearnside, L E Leightley
Evaluation of substituted isothiazolone as a potential new wood preservative
1984 - IRG/WP 3306
Laboratory decay tests were carried out with isothiazolone (4,5-dichloro-2-n-octyl-4-isothiazolone-3-one) treated wood. This compound was found to be extremely effective against three common wood decaying brown-rot fungi, exhibiting toxic threshold values in the range of 0.37 to 0.50 kg/m³. For the white-rot fungus, Coriolus versicolor, the toxic threshold values for treated pine and sweetgum wer...
D D Nicholas, A F Preston, D E Greenley, S V Parikh
Xylophene AS™, the challenge of developing a modern antisapstain formulation for the french market
2000 - IRG/WP 00-30250
In France Sodium Pentachlorophenol (NaPCP) has been used for more than 40 years for the protection of freshly cut and unseasoned lumber. The French sawmill industry requires a protection of 6 months and maximum 10% surface infection by moulds and/or sapstain fungi. However, this active substance did have some serious environmental flaws and no authorisation was granted for a direct contact of NaPC...
E Wozniak, L Cubizolles, N Delourme Fonseca, A R Valcke, J Gors
The suitability of isothiazolone microemulsions as long term wood preservatives
1997 - IRG/WP 97-30150
Microemulsion formulations of 4,5 dichloro-2-n-octyl-4-isothiazolin-3-one were investigated to determine the leaching potential of these formulation types as well as their efficacy against decay fungi. These patented low leaching formulations exhibited good anti fungal efficacy in standard tests combined with minimal leaching of the active ingredient from the wood. The data suggests that the excel...
B M Hegarty, Bing Yu, L E Leightley
Microemulsion formulations for wood protection chemicals
1993 - IRG/WP 93-30030
A microemulsion is a thermodynamically stable oil-water dispersion system. As a formulation it provides many unique features such as water compatibility for water-insoluble chemicals, formulation stability, good bioavailability and environmental acceptance. This paper discusses the major criteria for the formulations of water-insoluble wood biocides and the comparison in properties between convent...
Bing Yu, L E Leightley
In ground performance of wood treated with a substituted isothiazolone
1990 - IRG/WP 3612
Isothiazolones (I.T.A.'s) are a class of biocides that have potential for use as wood preservatives. The substituted ITA, RH-287, (4,5,dichloro-2-n-octyl-isothiazolone-3-one) is being evaluated as a broad spectrum wood preservative. The evaluation program includes in ground stake tests which were established at two test sites in Mississippi, USA The tests used southern yellow pine treated...
L E Leightley, D D Nicholas
Determination of thermal degradation of isothiazolone treated wood
1997 - IRG/WP 97-30154
Wood treated with 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one was the subject of thermal degradation study. The study included burning isothiazolone treated wood under various temperatures with and without oxygen. The result showed that no harmful combustion products, such as polychlorinated dibenzo-p-dioxins, polychlorinated dibenzo-p-furans and polychlorinated biphenyls, were detected. These fin...
Bing Yu
Performance of above ground decay test units treated with a substituted isothiazolone
1989 - IRG/WP 3503
RH 287, a substituted isothiazolone, was evaluated for efficacy against decay fungi in an above ground test in Mississippi. After 45 months of exposure, all test units that were pressure treated with this biocide at levels of 0.026 pcf and higher have no deterioration. In addition, the test units that were dip-treated with a solution concentration of 0.5% also have no deterioration. Compared to pe...
D D Nicholas, J A Wilson, D E Greenley
Effect of an antioxidant on the efficacy of organic wood preservatives in an accelerated soil contact decay test
2012 - IRG/WP 12-30583
In comparison to inorganic wood preservatives, organic biocides in transient carriers are considerably less effective when the treated wood is exposed to soil contact. Various oils are used in some formulations with pentachlorophenol to improve the efficacy. However, use of these oils imparts unacceptable properties to products used in residential applications. Consequently, there is a need to de...
D D Nicholas, J Shi, T P Schultz, L Sites
Termite resistance of copper-based preservative supplemented aspen strandboards
2012 - IRG/WP 12-30594
Termite resistance of aspen strandboards treated with various copper-based preservative systems was evaluated in field exposure tests. Five copper-based chemicals or zinc borate were blended into aspen furnish at three retention levels prior to pressing. Tebuconazole or 4,5-dichloro-2-N-octyl-4-isothiazolin-3-one (DCOI) were added as co-biocides to selected copper-based treatments. Sections from...
J J Morrell, C Vidrine, A Preston, L Jin
Effect of biodiesel on Performance of Isothiazolone
2013 - IRG/WP 13-30625
Biodiesel has a number of attractive properties, including the ability to readily solubilize a number of biocides and a tendency to reduce odors associated with other solvents such as petroleum-based diesel. Biodiesels, however, have also been implicated in reduced performance of some, but not all preservatives. It is important to assess the effects of biodiesel on each biocide. Soil block tests ...
Cheng Hua-Kang, L Jin, C Freitag, J J Morrell
Moisture and Fungal Durability of Wood-Plastic Composites Made With Chemically Modified and Treated Wood Flour
2013 - IRG/WP 13-40648
Evaluating the fungal durability of wood-plastic composites (WPCs) is complicated by the influence of slow moisture sorption. Recently, the American Wood Protection Association (AWPA) Standard Method E10, Testing Wood Preservatives by Laboratory Soil-Block Cultures, was modified to incorporate not only solid wood, but also wood-based composites and WPCs. To simulate long term WPC performance, cond...
B K Segerholm, R E Ibach