The preliminary evaluation of selected sulfonium salts for use in wood preservation
D V Plackett
Five sulfonium compounds, including two sulfonium methosulfates, one sulfonium bromide and two amphoteric sulfonium propanesulfonates, were prepared in crude form and subjected to various biocidal screening tests. A rapid screening test in which treated Pinus radiata pulp pellets were exposed to one of three wood-decaying fungi growing on malt agar revealed that dodecyl dimethyl sulfonium methosulfate had an inhibiting effect comparable to that of lauryl dimethyl benzyl ammonium chloride (benzalkonium chloride). The remaining sulfonium salts gave no fungal inhibition in this test. Both dodecyl- and decyl dimethyl sulfonium methosulfate gave a positive response in a screening test for insecticidal activity. However, rapid insect recovery indicated detoxification or excretion of the test chemicals. Dodecyl dimethyl sulfonium methosulfate was also screened as an anti-sapstain treatment with encouraging results. Further work is now in progress to explore the potential wood preservative capability of certain sulfonium and sulfoxonium salts.