112 An alternative to the HSE/NPL phase contrast test slide for airborne asbestos fibre analysis laboratories

More than 55 years ago, an analytical technique employing phase contrast microscopy was developed for the quantitative estimation of airborne asbestos fibre concentration. It was found that the detection limit of these microscopes was dependent upon microscope design, set-up and observer performance. In the late 1970’s the HSE/NPL Phase-Contrast Test Slide was developed that facilitated the standardisation of detection limits of microscopes and observers in laboratories around the world. An alternative test slide has now been developed using state of the art nano-metre fabrication technology, and is known as the Pickford Phase Contrast Test Slide, and manufactured by PhaseSlides. Both subjective and newly developed objective visibility testing show that the Pickford Test Slide is equivalent to the HSE/NPL Test Slide, and users report it to be much easier to use. Each Pickford Test Slide is certified by the Environmental Analytical Laboratory of the Southern Cross University – stating that it is equivalent in performance to that of the HSE/NPL test slide. Acknowledgement to the BOHS Annals of Work Exposures and Health.