The performance of metal-chromium-arsenic formulations after 32 to 38 years' in-ground exposure in Australia
G C Johnson, J D Thornton, J Beesley
Two trials of metal-chromium-arsenic preservatives were exposed in-ground in Australia. In Trial 1, Pinus radiata stakes treated with Boliden K.33, Boliden S.25, Celcure A, Tanalith C and Tanalith CA were installed at Sydney and Narrandera in 1961/1962. In Trial 2, P. radiata and Eucalyptus regnans sapwood were treated with Celcure A, Celcure A21-N, Celcure A 21-O and Tanalith CA (new) and installed at Sydney and Innisfail in 1966/1967. In Trial 1, all metal-chromium-arsenic preservatives at 8 and 12 kg m-3 gave median specimen lives in excess of 35 years. As none of the stakes treated to 12 kg m-3 with Boliden K.33, Celcure A, Tanalith C or Tanalith CA had become unserviceable, the minimum guarantee period for these preservatives is greater than the present exposure periods. In Trial 2, the four CCA preservatives when impregnated into P. radiata sapwood at 12 kg m-3 gave median specimen lives at Sydney of greater than 32.5 years. With E. regnans sapwood treated to 12 kg m-3, only Celcure A 21-0 gave a median specimen life at Sydney of greater than 32.5 years. At the high decay and termite hazard site of Innisfail, Celcure A 21-0 protected the eucalypt better than any of the other CCA formulations.
Keywords: CCA FORMULATIONS; FIELD TESTING; PERFORMANCE DATA; PINUS RADIATA; EUCALYPTUS REGNANS; BOLIDEN K.33; BOLIDEN S.25; CELCURE A; CELCURE A21-N; CELCURE A 21-O; TANALITH C; TANALITH CA