The Development of a Standard Hand Method and Correlated Surrogate Method for Sampling CCA (Pressure)-Treated Wood Surfaces for Chemical Residue

The U.S. Consumer Product Safety Commission (CPSC) staff completed a series of investigations that estimated the potential exposure and risk of young children to arsenic while playing on playground equipment composed of CCA (chromated copper arsenate)-treated wood. Prior to sampling in-use field structures composed of CCA-treated wood, studies were undertaken to create a standard sampling protocol for quantifying arsenic migration from CCA treated wood and to establish a correlation between the amount of chemical removed by a human hand and a cloth surrogate. These studies resulted in: 1) the development of an efficient extraction method for chemical residues collected on a human hand, 2) the development of a sampling device for consistent surrogate measurements, 3) establishment of a correlation between surrogate and hand measurements, and 4) the development of a standard human hand and surrogate sampling protocol for quantifying arsenic migration from CCA-treated wood. These studies also examined factors such as approaching a maximum hand load, effects of re-rubbing the same area of a board, and comparison of surrogate materials. The results from sampling CCA-treated wood with methods described in this article were later employed to obtain field data used in exposure and risk assessments.