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Laboratory decay tests using brown, white and soft rot fungi on wood treated with a series of dialkyldimethylammonium halides show that maximum fungitoxicity is exhibited by compounds with alkyl chains of 10 and 12 carbon atoms. Both the cation and the anion appear to influence effectiveness with bromide salts showing greater activity values than chloride analogs. The anion presumably influences effectiveness through distribution, fixation, and availability of the compounds rather than directly by changes in fungitoxicity. Monobromination of one of the alkyl chains caused a decrease in fungitoxicity, though the alkyl chain length-fungitoxicity relationship was the same as for the unsubstituted series of compounds. Addition of certain copper or organic biocides to alkylammonium compound formulations increased activity, particularly against soft rot. While this result is a significant advance, the complex relationships involved in such formulations will demand considerable further research in respect of efficacy, fixation, leaching, treatability, and environmental aspects before such a product could be commercialized.

The amount of southern pine lumber treated with chromated copper arsenate annually is considerable, yet the association of this preservative with the wood structure is not clear. The current study was undertaken to elucidate the nature of chemical reactions occurring between the components of the treating solution and the constituents of wood. Small, clear Southern pine samples were treated with six different preservative solutions (Cr; Cr/Cu; Cr/As; CCA-A; CCA-B; CCA-C), at 6.4 and 40 Kg/m3 (0.4 and 2.5 pcf) retentions, and compared to water treated and untreated controls. Samples were dried following treatment and analyzed by X-ray photoelectron spectroscopy (XPS). Evaluation of XPS data indicated that the preservative components reacted with wood, through aromatic and possibly alkene substitution, while oxidation of hydroxyl groups was not detected. The proposed wood/CCA bonding also offers an explanation for differences in hardwood and softwood durability following treatment.

The major components of untreated wood--cellulose, hemicellulose, and lignin--have not been implicated as toxicants, but extractive substances, especially in heartwood, can be toxic. Decay-resistant woods are more likely to contain irritants or sensitizers than nondurable woods. Short-term exposures to certain wood dusts may result in asthma, conjunctivitis, rhinitis, or allergic dermatitis, but long-term effects may include nasal cancer and Hodgkin's disease. Some thermophilic microorganisms found in wood are human pathogens, and septic splinters (chromomycosis) and inhalation of ascomycete spores from stored wood chips have been implicated in human illnesses. Reconstituted wood can contain formaldehyde resins, which pose health risks in enclosed humid areas. Pentachlorophenol (PCP)-treated wood is particularly toxic--short-term exposures to PCP-treating solutions can lead to aplastic anemia and mortality, while diseases such as Hodgkin's disease are associated with long-term exposures. Since much commercial lumber is dipped in PCP, the separation of the chronic effects of wood dust from PCP exposure is difficult. Chromated copper arsenate (CCA)- and ammoniacal copper arsenite (ACA)-treated wood may leach arsenic. CCA-treated wood is potentially safer, since it contains the pentavalent arsenic, which is a common constituent in the environment. ACA contains the trivalent arsenic, which is more toxic.

Although chromated copper arsenate (CCA) is one of the most important treatment methods for the prevention of decay in wood, the nature of wood/CCA reactions are not clear. The current study was undertaken to elucidate the nature of chemical reactions occurring between the components of the treating solution and the constituents of wood. Small, clear Southern pine samples were treated with six different preservative solutions (Cr; Cr/Cu; Cr/As; CCA-A; CCA-B; CCA-C), at 6.4 and 40 Kg/m3 (0.4 and 2.5 pcf) retentions, and compared to water treated and untreated controls. Samples were dried following treatment and analyzed by diffuse reflectance Fourier transform infrared spectroscopy (DRIFT). Evaluation of DRIFT data indicated that the preservative components reacted with the aromatic and carbonyl groups in wood.

The distribution gradients of arsenic and chromium in soil around and below nominal 50- by 101-mm (2- by 4-in) southern pine stakes that were treated with either chromated copper arsenate (CCA Type I or Type II) or in ammoniacal copper arsenate (ACA) and exposed for nearly 30 years in Poarch fine sandy loam soils in southern Mississippi indicate that the small amounts of As and Cr that move from the stakes into the soil are sorbed by the soil proximal to the stakes. The distribution gradient for copper about the stakes is similar to those for As and Cr, but is less precise. These findings support the hypothesis that CCA- and ACA-treated wood, at least in acidic soils such as the Poarch fine sandy loams, will not contribute significant amounts of As or Cr into surrounding soils and waters.

Les premiers essais realises montrent que l'extrait methanolique de Robinia pseudoacacia possede un potentiel important pour la preservation du bois de tremble et de pin contre l'attaque par Gloeophyllum trabeum et Pleurotus ostreatus

The wood preservative chromated copper arsenate (CCA) is a very widely used product. As it contains both copper and arsenic, it is not dissimilar to the pigments Scheele's green and Schweinfurter's green which were found to be biologically convertible to the toxic Gosio gas (B. Gosio, Ber. 30:1024-1026, 1897) later identified by Challenger and co-workers as trimethylarsine (F. Challenger, Adv. Enzymol. 12:429-491, 1951). Thus, it was of interest to determine whether microbiological action on CCA and wood treated with CCA could result in the production of trimethylarsine. We report that the fungus Candida humicola will produce this arsine from dilute solutions of CCA and from wood soaked in CCA.

The service life of wood treated with Chromated Copper Arsenate (CCA) may be 30 years or even more due to the strong fixation of CCA in wood. The strong fixation also means that when the wood is removed from service, a large proportion of the copper, chromium and arsenic is still present and will enter into the waste stream unless actions are taken to prevent this. While the use of CCA is regulated in many countries, the handling of the waste wood is often not. The amount of treated wood being removed from service is expected to increase dramatically over the next few decades.

Widespread use of chromated copper arsenate (CCA) as a wood preservative has led to increasing public concern regarding possible toxic contamination of areas surrounding CCA‐treated structures, e.g., decks, playground equipment, etc. Appreciable leaching of arsenic, chromium, and copper into soils adjacent to such structures has been demonstrated via standard techniques of analytical chemistry. The advantages of PIXE [rapid analysis, quick sample turnover, possible lower cost] suggest its application to this area of interest. PIXE studies in our laboratory of CCA‐contaminated soil samples show good agreement with previous analyses of As, Cu, Cr, and other heavy‐elemental content, with some variability in diffusion rates.

Destructive and nondestructive (NDE) tests were performed on 25 untreated and 75 chromated copper arsenate (CCA) treated red pipe poles to determine basic strength properties and the effects of treatment and strain rate. Test results are compared to previously reported data and to the ANSI 05.1 fiber stress rating and show that the ANSI stress rating continues to be adequate for its intended purpose. A comparison of visual and NDE methods for strength grading showed similar results at ground-line, but the NDE method provided greater accuracy at other locations. >