Validation of the analysis of respirable crystalline silica (quartz) in foams used with CIP 10-R samplers.

Sampling the respirable fraction to measure exposure to crystalline silica is most often carried out using cyclones. However, low flow rates (<4 l min(-1)) and continuing improvement in workplace hygiene means less and less material is sampled for analysis, resulting in increased analytical uncertainty. Use of the CIP 10-R sampler, working at a flow rate of 10 l min(-1), is one attempt to solve current analytical difficulties.

Producing samples for the organization of proficiency tests. Study of the homogeneity of replicas produced from two atmosphere generation systems.

This article describes two atmosphere generation systems used for the production of replicas. The first, the Sputnic system, is based on the Sputnic air sampler developed by the National Institute of Occupational Health in Oslo (Norway). It is used to generate asbestos fibres or silica particles and allows the simultaneous production, by means of sampling on filters, of up to 114 replicas.

Laboratory study of selected personal inhalable aerosol samplers.

Assessment of inhalable dust exposure requires reliable sampling methods in order to measure airborne inhalable particles' concentrations. Many inhalable aerosol samplers can be used but their performances widely vary and remain unknown in some cases. The sampling performance of inhalable samplers is strongly dependent on particle size and ambient air velocity.

Comparison of direct and indirect methods of measuring airborne chrysotile fibre concentration.

Transmission electron microscopy observations most frequently form a basis for estimating asbestos fibre concentration in the environment and in buildings with asbestos-containing materials. Sampled fibres can be transferred to microscope grids by applying either a direct [ISO (1995) Draft International ISO/DIS 10312. Ambient air.

An International comparison of the crystallinity of calibration materials for the analysis of respirable alpha-quartz using X-ray diffraction and a comparison with results from the infrared KBr disc method.

It is important that analytical results, produced to demonstrate compliance with exposure limits are comparable, to ensure controls are monitored to similar standards. Correcting a measurement result of respirable alpha-quartz for the percentage of crystalline material in the calibration dust is good analytical practice and significant changes in the values assigned to calibration materials will affect the interpretation of results by an analyst or occupational hygiene professional. The reissue of the certification for the quartz reference material NIST 1878a in 2005 and differences in comparative values obtained by other work created uncertainty about the values of crystallinity assigned to national calibration dusts for alpha-quartz.

ALASCA proficiency testing scheme for occupational hygiene laboratories.

Nowadays, quality assurance is an important part in the environment of analytical laboratories, who need to prove their ability to perform analysis as well to handle routine control as research and development analysis. A proficiency testing scheme (PTS) is one of the possible and powerful tools to evaluate both bias and dispersion of the analysis. As far as industrial hygiene is concerned, since analytical uncertainty is insignificant with regard to sampling strategy uncertainty, laboratories could be tempted to neglect analytical uncertainty assessment as well.

Occupational exposure to mineral fibres: analysis of results stored on colchic database.

The aim of this paper is to present fibre exposure data recorded on the COLCHIC database. This database consolidates all occupational exposure data collected in French companies by the Caisses Régionales d'Assurance Maladie (regional health insurance funds, CRAM) and the Institut National de Recherche et de Sécurité (national institute for research and safety, INRS). A total of 8029 concentration results, expressed in number of fibres measured by phase-contrast optical microscopy, are available for exposure to asbestos fibres, ceramic fibres and man-made mineral fibres other than ceramic fibres.

Effect of using a cowl when measuring the fiber number concentration by the membrane filter method.

This article compares samples taken with three different sampling heads: (1). open-faced sampling head, (2). open-faced sampling head with stainless-steel extension cowl, and (3).