Comparison of methods for monitoring solid particulate surface contamination in the workplace

This paper reports an assessment of various methods for sampling particulate surface contamination for use in the field. The results from the study will be used to develop guidance for monitoring particulate surface contamination in the workplace. Three types of adhesive tape, two manual and two `semi-automatic' wipe methods, and one Smair method were assessed. A field assessment of selected methods was carried out in two stages. In stage one, the manual wipes, semi-automatic wipes and adhesive tape (Scotch Tape®) were compared. In stage two, the adhesive tape (Scotch Tape®), black forensic tape, clear forensic tape and Smair were compared. Visits were made to ten metal processing facilities and particulate contamination was sampled from six locations at each site. Sampling locations were chosen for their potential as points of worker dermal contact and also to represent a range of surface characteristics. The metal content of the samples were analysed using Atomic Absorption Spectrophotometry (AAS) and X-ray Fluorescence Spectrometry (XRF). It was found that the Smair method proved to be inefficient in removing surface contamination, particularly where the surface was damp or greasy. Tape methods were found to be the most satisfactory and have considerably greater efficiency than wipe sampling. The black forensic tape is the preferred sampling medium as it is highly efficient, reproducible and easy to use.