Institute for Transportation

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.