Recent policy and technical developments in biological monitoring in the United Kingdom.

In 1996 the United Kingdom's Health and Safety Executive introduced biological monitoring guidance values for six substances, butoxyethanol, N,N-dimethylacetamide, lindane, methylene-bis(2-chloroaniline), mercury and methylenedianiline. These guidance values were set as either health-based values or hygiene-based values calculate according to the 90th percentile (benchmark concept). Recent technical developments from the Health and Safety Laboratory are described in this paper and include: (i) the use of breath analysis as a useful non-invasive routine monitoring technique; (ii) flow cytometry as a means for measuring different patterns of immune cell activation from workers exposed to respiratory sensitisers when compared with those exposed to chemical irritants; (iii) the use of molecular techniques to explore the possible role of individual susceptibility in the development and severity of glomerulonephritis; (iv) the development of expert systems for predicting the skin permeability of chemicals, and respiratory and skin sensitisation.