Wood Preservatives Research Articles

Experimental study on the factors affecting smouldering behaviour of CCA-treated wood

Waterborne chromated copper arsenate (CCA) is a highly effective, widely used wood preservative. While it does not appear to markedly alter the flaming behaviour of treated wood, there are significant concerns regarding post-fire smouldering. Our understanding of the mechanisms and factors affecting smouldering behaviour is currently insufficiently developed. This study used a multiscale approach to better understand smouldering in slash pine treated to different CCA retentions and investigated reaction kinetics through thermogravimetric analysis (TGA) in addition to Cone Calorimeter smouldering tests. Derivative thermogravimetry (DTG) showed that the temperatures at the onset of pyrolysis and oxidation, and where the maximum rate of decomposition occurred were both lowered by CCA treatment, and effects became more pronounced as CCA retention increased. Bench-scale smouldering tests showed that the smouldering mass loss rate increased with higher CCA retention, lower wood density, and prolonged heat exposure. Smouldering mode changed from a steady to an unsteady pattern as CCA retentions decreased to a threshold from combined pyrolysis and oxidation to isolated char-to-ash oxidation. Once initiated, the reaction can be self-sustaining until all the mass has been consumed regardless of the initial smouldering rate.

Study on Improving in the Evaluation of Untreated Specimens in the Decay Resistance Effect of Wood Preservatives

This study emphasizes the importance of verifying the vitality of test fungi through the results of untreated specimens in the evaluation of the efficacy of wood preservatives. However, in many cases, the weight loss of the untreated specimens does not meet the criteria in the Korean standard(KS) test method, so we devised an efficient and simplified test method by cross-applying the American Wood Protection Association (AWPA) standard method. The study found that the feeder strip inoculation method specified in the soil block test(AWPA) was more effective than the KS standard, resulting in a higher weight loss (%) of the wood blocks. Among the strains used, <i>Trametes versicolor</i> KACC54448(white rot fungus) showed weight loss rate of 34.1% and <i>Tyromyces palustris</i> and <i>Fomitopsis pinicola</i> KACC53387(brown rot fungi) showed weight loss rates of 63.9%, 58.0%, respectively. Furthermore, we found that maintaining a relative humidity of around 50% by placing distilled water in a low-temperature incubator was sufficient to create an environment in which the test fungi could decay the wood blocks without using expensive equipment such as a constant temperature and humidity chamber. As a result, it was confirmed that the activity of the test fungi can be increased even under conditions of around 50% relative humidity without the shaking cultivation process of the test fungi.

Upgrading the durability of perishable wood species using extractives from side streams of durable wood sawmill operations: a review

Abstract Natural durability is one of the most rated features in wood end-use applications. In fact, several precious native tropical wood species produce timber of high natural durability, which is also related to long service life even for the highest hazard classes. However, selective logging is driving the existing volume of this group of species to near extinction. The remainder of the alternative species produces perishable timbers, which require synthetic chemical protection to prolong their service life but with detrimental effects on humans and the environment. Therefore, transferable durability has emerged as an alternative to gradually substitute traditional wood preservatives. From this approach, extractives from naturally durable wood species are removed and transferred to the non-durable wood species as an alternative environmental-friendly option for wood protection. Indeed, extractives from durable wood species have proven to have a deterrent effect on fungi, bacteria and termites and could be used to protect perishable wood species. Thus, this review aims to assess the prospects of developing environmentally friendly wood preservatives based on extractives sourced from highly natural, durable wood species to treat and add value to the group of perishable timbers. A step-wise analysis offers insights and challenges on (i) potential sources of extractives; (ii) effective extraction methods; (iii) extractive-based preservative formulation; and (iv) effective treatment methods for better preservative fixation for better wood protection. Accounts about the way forward for the development of extractive-based wood preservatives are also presented.

Evidence of Unrecognized Indoor Exposure to Toxic Chlorophenols and Odorous Chloroanisoles in Denmark, Finland, and Norway

Production and use of chlorophenols (CPs) are being phased out around the globe, but with considerable lag in some highly populated countries. The process could be incentivized by leading countries sharing their experiences on problems that occurred, including the built environment. We previously reported that Swedish industry and authorities promoted CPs, including pentachlorophenol (PCP), as wood preservatives in buildings for decades. Yet, Swedish indoor research did not recognize exposure to the hazardous CPs and their odor potent derivatives, the chloroanisoles (CAs), which smell like mold and still evolve from legacy preservatives in damp building structures. We hypothesized that the toxic CPs and odorous CAs could be key players for health and odor problems not only in Sweden but also in the neighboring Nordic countries. We found no reports in scientific medical literature of CPs being used in buildings in these countries. However, grey literature shows that CPs were indeed used, even during building booms, in house exteriors, constructions, and interiors, from the 1950s up to the late 1970s (Denmark) and even the 1990s (Finland and Norway). One application of CPs was in houses erected on dampness-prone house foundations, conditions ideal for formation of odorous CAs through microbial methylation. Furthermore, our searches suggest that these problematic chemicals played hitherto unrecognized key roles when indoor air research evolved. Thus, odor became an important aspect of the “sick building syndrome” in Denmark and an early warning sign of health risks in Finland, as asthma and allergy were attributed to “dampness and mold.” None of the countries addressed the possible links between odor and health effects and exposure to CAs and CPs. In conclusion, our results suggest that unrecognized indoor exposure to toxic CPs and odorous CAs has mislead Nordic indoor air research for decades.

Characteristics of Simalambuo (Lophopetalum sp.) wood from Nias Island, North Sumatra Province, Indonesia

Abstract. Iswanto AH, Amanda DW, Gea S, Susilowati A, Fatriasari W, Darwis A, Lubis MAR, Sucipto T, Syahidah, Subekti N, Hartono R, Sutiawan J, Hidayat W, Kim NH. 2023. Characteristics of Simalambuo (Lophopetalum sp.) wood from Nias Island, North Sumatra Province, Indonesia. Biodiversitas 24: 4193-4201. Simalambuo (Lophopetalum sp.) wood is commonly used for construction materials in Nias Island, North Sumatra Province especially in the aftermath of the devastating earthquake that affected the region. However, information regarding the fundamental characteristics of this wood has not been available. Therefore, this research aimed to evaluate the basic properties of Simalambuo wood, such as its physical, mechanical, chemical, and natural durability. The destructive method was used to determine the physical and mechanical parameters (i.e., specific gravity, moisture content, shrinkage, MOE, MOR, and hardness) using a small clear specimen sample under the BS 373 standard (1957). The chemical components of wood (i.e., holocellulose, cellulose, lignin, extractives) were analyzed using a variety of methods, including CRC Press methods, LAP NREL 003 standard, and TAPPI. Meanwhile, the SNI 7207-2014 standard was utilized to evaluate its resistance against subterranean termites. The results showed that Simalambuo wood has an average specific gravity of 0.42 and a T/R ratio of 1.78. Based on its specific gravity, the wood is classified within the strength class III-IV. It also exhibits a reduced cellulose and extractive content, along with a higher proportion of lignin. In terms of durability, it is classified as class IV, implying non-resistance to termites’ attack and necessitating wood preservation treatment for its practical application. The findings of this study suggest the application of this wood is recommended for light construction, furniture, and other functions, but not for heavy construction.

The use of isothermal calorimetry to measure corrosion rates of metals in contact with preservative-treated wood

The purpose of this paper is to examine whether isothermal microcalorimetry can be used to determine the corrosion rates of metals embedded in wood. Metal fasteners were driven into dowels of wood treated with alkaline copper quaternary, a common wood preservative that increases the corrosiveness of wood. The dowels were stored in a nearly 100% relative humidity environment at 27°C for one year; throughout the exposure period, dowels were removed and the thermal power generated by the sample was measured in an isothermal calorimeter. Measurements over the 1-year exposure showed that the thermal power depended upon the wood moisture content and ranged from 0 to 200 µW. The heat, determined by integrating thermal power over time, was higher than expected compared with the total amount of mass lost due to corrosion at the end of the experiment. Despite this, the technique shows promise as a method to determine how changes in wood moisture content affect the corrosion rates of metals in contact with preservative treated wood.

Preservatve Potentials of Datura metel Seed Oil on Triplochiton scleroxylon Wood (Schumann)against Fungal Attack

This experiment was carried out to evaluate the potential of extracted Datura metel seed oil as a bio wood preservative against fungi attack as reports have shown bio-preservatives to be toxic free and environmentally friendly. The oil was extracted from the seed by Soxhlet apparatus using N-Hexane and ethanol solvents and using volume-to-volume method of dilution kerosene (at 50%) was added to increase its quantity thereafter. The phytochemical screening of the seed of Datura metel revealed the presence of tannins, alkaloids, flavonoids, saponins and phenols. Wood samples of Triplochiton sceleroxylon were cut to 20 × 20 × 60mm and the dimensioned wood samples were soaked for 72 hours in the seed oil extract hence preservative absorption rate and percentage weight loss of wood was determined on exposure to a purely cultured Sclerotium rolfsil (brown rot fungi) and Pleurotus ostreatus(white rot fungi). Data obtained were subjected to analysis of variance at α0.05 and the results showed the highest value of mean weight loss of 18.29% while the samples exposed to brown rot fungi has a mean value of 14.12% and white rot a lowest mean value of 12.72%. The highest absorption was observed to be 92.73 kg/m at 100 % concentration level of D,metel extract. Based on the results obtained, the seed-oil extracts of Datura metel have the potential of being an effective wood preservative.

Study of Boron Complexation with Pyridoxine: Effect of Interaction Time, Temperature, and Amount of Pyridoxine

Borax is one of the compounds of boron (B), which is widely used as an anti-fungal, wood preservative, and antiseptic in cosmetics. Boron can form complexes with biomolecules such as pyridoxine, so it is interesting to know the interaction between borax and pyridoxine. This study seeks to investigate the complexation of boron, which is obtained from borax, with pyridoxine under various conditions of time, temperature, and the amount of pyridoxine. The resulting complex was characterized by UV-Vis spectrophotometry, Fourier Transform Infrared (FT-IR), and X-Ray diffraction (XRD). The study was initiated by optimizing the complexation of boron and pyridoxine. The maximum wavelengths of pyridoxine were found in the 205 nm and 292 nm regions, while the boron-pyridoxine complex was found in the 237 nm region. The obtained contact time, temperature, and amount of pyridoxine are 40 minutes, 60 °C, and 2 mL respectively. The results of the Fourier transform infrared (FT-IR) analysis of the boron-pyridoxine complex showed that there were OH groups, aromatic C=C groups, aliphatic C-C groups, B-H groups, and B-O groups. The results of the XRD analysis of the boron-pyridoxine complex obtained a diffraction angle of 30.93°

Efficacy of Certain Inorganic Salts, as A Wood Preservative, on Bamboo Beetle, Dinoderus minutus Fab., (Coleoptera: Bostrychidae)

Efficacy of Certain Inorganic Salts, as A Wood Preservative, on Bamboo Beetle, Dinoderus minutus Fab., (Coleoptera: Bostrychidae)

Lignin Nanoparticles with Entrapped Thymus spp. Essential Oils for the Control of Wood-Rot Fungi.

After decades of utilization of fossil-based and environmentally hazardous compounds for wood preservation against fungal attack, there is a strong need to substitute those compounds with bio-based bioactive solutions, such as essential oils. In this work, lignin nanoparticles containing four essential oils from thyme species (Thymus capitatus, Coridothymus capitatus, T. vulgaris, and T. vulgaris Demeter) were applied as biocides in in vitro experiments to test their anti-fungal effect against two white-rot fungi (Trametes versicolor and Pleurotus ostreatus) and two brown-rot fungi (Poria monticola and Gloeophyllum trabeum). Entrapment of essential oils provided a delayed release over a time frame of 7 days from the lignin carrier matrix and resulted in lower minimum inhibitory concentrations of the essential oils against the brown-rot fungi (0.30-0.60 mg/mL), while for the white-rot fungi, identical concentrations were determined compared with free essential oils (0.05-0.30 mg/mL). Fourier Transform infrared (FTIR) spectroscopy was used to assess the fungal cell wall changes in the presence of essential oils in the growth medium. The results regarding brown-rot fungi present a promising approach for a more effective and sustainable utilization of essential oils against this class of wood-rot fungi. In the case of white-rot fungi, lignin nanoparticles, as essential oils delivery vehicles, still need optimization in their efficacy.

Analysis of Borax Content in Meatballs that are Sold in The Karang Jangu Environment

Meatballs are one of the foods that are popular with various groups in Indonesia. Borax is a prohibited substance used as a food additive. Borax is commonly used in soldering, glassmaking, porcelain and wood preservatives. The use of borax in crackers aims to increase the elasticity of the meatballs. The purpose of this study was to detect the presence of borax in meatball samples.This type of research is descriptive, the method used is a qualitative method. Meatball samples were taken from meatball traders who sold them in the Karang Jangu area, Meatball samples were taken from meatball traders who sold them in the Karang Jangu area and examined using tumeric paper, tumeric paper (curcumin paper) is filter paper that is dipped in turmeric solution and dried, after that the sample that has been diluted and homogenized is dripped onto the tumeric paper. Based on the results of the study of the five meatball samples that were examined qualitatively using tumeric paper, negative results were obtained or did not contain borax, this was made clear by the absence of a color change on the tumeric paper. It is hoped that future researchers can use other methods. which can detect the presence and levels of borax in meatballs.

Oral administration of curcumin and gallic acid alleviates pentachlorophenol-induced oxidative damage in rat intestine.

Pentachlorophenol (PCP) is used as pesticide and wood preservative. We have previously shown that PCP causes oxidative damage in rat intestine. This study aimed to delineate the possible therapeutic potential of curcumin (CUR) and gallic acid (GA) against PCP-induced damage in rat intestine. PCP alone group received 125mg PCP/kg body weight/day orally for 4 days. Animals in combination groups received CUR or GA (100mg/kg bw) for 18 days and PCP (125mg/kg bw) for the last four days. Rats were sacrificed and intestinal preparations were analyzed for various parameters. Administration of PCP alone altered the activities of metabolic, antioxidant and brush border membrane enzymes. It also increased DNA-protein crosslinking and DNA-strand scission. Animals in combinations groups showed significant amelioration against PCP-induced oxidative damage. Histological abrasions were seen in PCP alone group which were reduced in the intestines of combination groups. CUR was more effective protectant than GA. CUR and GA protected rat intestine from PCP-mediated changes in the activities of metabolic, antioxidant and brush border membrane enzymes. They also prevented DNA damage and histological abrasions. The antioxidant character of CUR and GA may be responsible for the diminution of PCP-mediated oxidative damage.

Design, Synthesis and Biological Activities of (Thio)Urea Benzothiazole Derivatives.

(Thio)ureas ((T)Us) and benzothiazoles (BTs) each have demonstrated to have a great variety of biological activities. When these groups come together, the 2-(thio)ureabenzothizoles [(T)UBTs] are formed, improving the physicochemical as well as the biological properties, making these compounds very interesting in medicinal chemistry. Frentizole, bentaluron and methabenzthiazuron are examples of UBTs used for treatment of rheumatoid arthritis and as wood preservatives and herbicides in winter corn crops, respectively. With this antecedent, we recently reported a bibliographic review about the synthesis of this class of compounds, from the reaction of substituted 2-aminobenzothiazoles (ABTs) with iso(thio)cyanates, (thio)phosgenes, (thio)carbamoyl chlorides, 1,1'-(thio)carbonyldiimidazoles, and carbon disulfide. Herein, we prepared a bibliographic review about those features of design, chemical synthesis, and biological activities relating to (T)UBTs as potential therapeutic agents. This review is about synthetic methodologies generated from 1968 to the present day, highlighting the focus to transform (T)UBTs to compounds containing a range substituents, as illustrated with 37 schemes and 11 figures and concluded with 148 references. In this topic, the scientists dedicated to medicinal chemistry and pharmaceutical industry will find useful information for the design and synthesis of this interesting group of compounds with the aim of repurposing these compounds.

Biochemical and histopathological effects of copper oxide nanoparticles exposure on the bivalve Chambardia rubens (Lamarck, 1819).

Copper nanoparticles are widely incorporated into many applications, including air and liquid filters, wood preservatives, batteries, thermal and electrical conductivity, inks and skin products. Their potential toxicity and environmental fate, however, are poorly studied in the freshwater bivalves. The aim of the present study was to evaluate the different effects of copper oxide nanoparticles and ionic copper on the digestive glands and gills of the mussel Chambardia rubens. Mussels were treated with 100 and 1000 µg Cu L-1 of copper oxide nanoparticles (CuONPs) or ionic copper (Cu2+) for 3, 7, and 14 days. The Cu accumulation and markers of oxidative stress in the digestive glands and gills were evaluated. The results show that the digestive gland collected higher levels of the two forms of copper than the gills. Exposure to CuONPs or Cu2+ induced significant elevations in superoxide dismutase, glutathione peroxidase and lipid peroxidation. Notably, a significant decrease was observed in the glutathione levels after exposure to both copper forms. CuONPs only induced a significant increase in glutathione reductase and glutathione S-transferase. The ionic copper only induced a significant decrease in catalase activities in the gill tissues. Overall, CuONPs and Cu2+ provoked oxidative stress, and further research is needed to clarify their genotoxic and neurotoxic effects on freshwater mussels and other biota.

Treatability Changes of Radiata Pine Heartwood Induced by White-Rot Fungus Trametes versicolor

Desired retention and depth into wood are necessary for wood preservatives to provide long-term durability. In general, heartwood of wood is difficult to treat, and bioincising was investigated as a potential technique to improve the treatability of refractory wood and heartwood. In order to study the effects of bioincising treatment with white-rot fungus Trametes versicolor on the pore structure and treatability of radiata pine heartwood, this research conducted tests of mass loss, microscopic structures, pore structure parameters, uptake, and penetration of preservative of radiata pine heartwood specimens incubated by T. versicolor for 4, 8, and 12 weeks. The results showed that the optimal inoculation time of T. versicolor bioincising on radiata pine heartwood was 4 to 8 weeks. At this time, the retention of injected preservatives increased by 5.01%–17.73%, the penetration depth of preservatives increased significantly, and the corresponding mass loss was 3.04%–6.45%. The results of microstructure and pore structure showed that T. versicolor entered the adjacent tracheids via apertures, with less impact on the cell wall, mainly degrading pit membranes and ray parenchyma cells early in the inoculation of radiata pine heartwood. As the structures impeding fluid flow were connected, the porosity of the wood and the range of the main pore size distribution increased significantly, thus increasing the treatability of radiata pine heartwood.

Effect of Neem Extract on Fungus Inhibition in Toona ciliata M. Roem.

The increasing human population and continuous demands of timber and its derived products like composite wood, has created a significant pressure on the demand for high quality timber from forests. This, ultimately has resulted in pressurising the natural forests and increase in the unvailibility of the production of high quality or durable timber from the forests. The one way to neutralize this pressure on the forests is to modify the other non durable wood species having undesirable properties like hygroscopicity, anisotropy, dimensional instability and biodegradability. Treatment with neem extracts as a biopreservative proves to be very efficient to protect the wood from bacterial or fungal rots. In the present study, wood specimens of Toona ciliata M. Roem. were treated with neem leaf and seed extracts for 72 hours in concentrations of 0.25, 0.5, 1, 1.5 and 2% (w/v), and analyzed for fungal growth and inhibition on dry weight basis using Polyporous rubidus. The fungal growth was maximum in untreated (control) samples whereas, minimum growth was observed in the neem leaf and seed extracts with 2.00% concentration. This method comes to be one of the most eco-friendly processes of wood preservation and helps in utilization of Toon wood in more effective and sustainable way. Also, the minimal release of harmful chemicals in the environment, helps to widen the industrial applications of Toona ciliata wood and make its acceptance to the society with ease.

Fire resistance of pine wood treated with phenol-formaldehyde resin and phosphate-based flame retardant

ABSTRACT Wood is a commonly used material in construction. However, its application is limited due to its flammability. Modification of wood with phenol-formaldehyde resin (PF) can improve many of its inherent properties, but does not upgrade its fire resistance. To address this issue, Scots pine (Pinus sylvestris L.) sapwood was impregnated with a low molecular weight PF resin and phosphate-based flame retardant (FR). The fixation of the FR was evaluated using an accelerated ageing procedureaccording to the EN 84 standard (CEN 2020: EN 84 (2020) Wood Preservatives – Accelerated Ageing of Treated Wood Prior to Biological Testing - Leaching Procedure (Brussels, Belgium: European Committee for Standardization)). The thermal stability, flammability and heat release of treated wood were analysed before and after a leaching test. The combination of PF and FR treatment significantly improved the thermal stability, reduced flammability and decreased the heat release, as evidenced by a 82% and 86% reduction in total heat release within 600 s compared to untreated wood and pure PF-treated wood, respectively. The improved fire performance was also observed for the leached wood.

Pentachlorophenol-induced hemotoxicity diminishes antioxidant potential and oxidizes proteins, thiols, and lipids in rat blood: An in vivo study

Pentachlorophenol (PCP) is an excessively used wood preservative and pesticide, which has resulted in human exposure raising concerns about its potential toxic effects. This study is designed to evaluate the hemotoxicity of PCP in adult rats. Wistar rats were orally administered PCP (25–150 mg/kg bw) for five days while untreated (control) rats received corn oil. Animals were sacrificed, blood was taken and fractionated into plasma and red blood cells (RBC). PCP administration increased methemoglobin formation but decreased methemoglobin reductase activity. Significantly increased hydrogen peroxide level indicates initiation of oxidative stress condition in blood. PCP increased the oxidation of thiols, proteins and lipids, lowered glutathione levels, and compromised the antioxidant status of RBC in treated rats. Enzymes of the pathways of glucose breakdown, glycolysis and phosphogluconate pathway, were inhibited. Markers of liver damage were increased in the plasma of PCP-treated rats suggesting hepatotoxicity. This was confirmed by histopathological analysis of stained liver sections. Activity of xanthine oxidase, a reactive oxygen species (ROS) generating pro-oxidant enzyme, was increased. These hematological changes could be a result of the increased generation of ROS or direct chemical transformation by transient reaction species. These results show that PCP induces redox imbalance, diminishes antioxidant potential, inhibits metabolic pathways, and oxidizes cellular components in rat blood.This study suggests an elaborated possible molecular mechanism of PCP toxicity, and similar compounds so that methods can be devised to minimize its damaging effect.

Wood Vinegars: Production Processes, Properties, and Valorization

Abstract Pyrolysis of lignocellulosic biomass is widely used for the production of charcoal, pyroligneous liquid, and noncondensable gases. All three are value-added products that are exploited in several fields. However, this review focuses on three main areas: wood vinegar production methods, its physicochemical properties, and the use of wood vinegar or pyroligneous acid in agriculture and the environment. Wood vinegar is a liquid derived from wood by the condensation of gases and vapors released during the carbonization process, which is the transformation of wood into charcoal. It is mainly composed of aliphatic, aromatic, and naphthenic hydrocarbons and other oxygenated compounds such as alcohols, aldehydes, ketones, furans, acids, phenols, and ethers. Wood vinegar has antioxidant and free-radical-scavenging properties and is used in agriculture as an antimicrobial, antifungal, insecticide, and plant germination and growth agent. It is also used in food preservation, in medicine, and in the ecological preservation of wood. This review also examines the state of the art in pyroligneous liquid production techniques and factors that could potentially affect its quality.

Development of a safer and improved analytical method for polycyclic aromatic hydrocarbons in creosote products

Polycyclic aromatic hydrocarbons (PAHs) in creosote products used for wood preservation are regulated in Japan. Although the analytical method for this regulation has been stipulated by law, two main problems have been highlighted, namely the use of dichloromethane, a potential carcinogen, as a solvent and inadequate purification. Therefore, an analytical method to solve these problems was developed in this study. Actual creosote-treated wood samples were examined, and it was found that acetone could be used as an alternative solvent. Purification methods using centrifugation, silica gel cartridges, and strong anion exchange (SAX) cartridges were also developed. It was found that the SAX cartridges strongly retained PAHs, and an effective purification method was developed using this phenomenon, in which contaminants were removed by washing with diethyl ether/hexane (1/9 v/v), which could not be achieved with a silica gel cartridge. This strong retention was attributed to cation–π interactions. The analytical method developed in this study yielded good recoveries (81.4–113.0%) with low relative standard deviations (<6.8%), and the limit of quantification (0.02–0.29 µg/g) was significantly lower than the current creosote product regulation. Therefore, this method can safely and effectively extract and purify PAHs from creosote products.