Evaluation of New Creosote Formulations

This study compared two new formulations of creosote and one pigment-emulsified creosote (PEC) with a formulation of creosote that met requirements of the AWPA standard P1/P13 for creosote. Two softwood and two hardwood species were treated to four retention levels with each formulation. The four creosote formulations were evaluated by (1) soil-block test, (2) fungal cellar test, and (3) field test. This paper presents results from the soil-block tests and preliminary findings from the fungal cellar tests after 72 weeks. The field stakes have been exposed for only 1 year, thus these data are not available. Data from the fungal cellar tests show that softwoods are protected much better than hardwoods for all four formulations of creosote tested. The soil-block tests show comparable performance in softwood and hardwoods. No major difference between formulations was detected in the two laboratory tests.