Numerous scientific studies concerning the determination of workplace protection factors (WPFs) indicate that the level of protection shown by laboratory testing to be presented by respiratory protective devices cannot be attained at real-case workplaces. A WPF is calculated by formation of the quotient of the hazardous substance concentration (gases or particles) within the facepiece and the corresponding ambient concentration. Its calculation therefore requires measurements of the total leakage. The conditions (such as the task, severity of the work, environment) under which the total leakage is determined in laboratory tests differ markedly from those encountered by users in practice. In other words, the tasks performed by the test subjects during laboratory testing do not reflect the conditions at real-case workplaces. Since a harmonized method for determining workplace protection factors (for example determining of the total leakage in the laboratory, workplace studies) does not exist in Europe, the WPFs differ from country to country, in some cases considerably.
One of the objectives of this project was therefore the development of a standardized method and strategy for determining workplace protection factors for a range of respiratory protective devices. Test series were then to be performed at real-case workplaces in order to determine the actual situation. In the final phase, a training programme was to be developed for the test subjects, and its effectiveness measured. For this purpose, the results obtained with individual test subjects before and after training were compared.
The project comprised two stages. The first stage involved planning and conceptual design, and selection and evaluation of the test method and strategy. In the second stage, several test series were performed on respiratory protective devices at real-case workplaces. The measured data were then to enable parameters to be identified which are ultimately used to determine the desired workplace protection factors.
The project was conducted under the umbrella of PEROSH by an international group of test bodies primarily concerned with occupational safety. As many real-case working areas as possible were to be studied. The test method used was to be kept as simple as possible and was to be sufficiently robust to permit its use under the required conditions. Nature of the project: multi-centre study (in co-operation with PEROSH partners)
A number of modules were developed during the first stage of the project. An introductory seminar was to be conducted for individuals with responsibility in companies and involved in measurements, and a framework guidance document produced. These measures were to assure reproducible underlying measurement conditions at all times. Two further modules concerned the selection of suitable workplaces and of the corresponding respiratory protective devices. The precise conditions and circumstances of the workplaces were determined by means of a survey instrument specially developed for this purpose. The core activity in this stage was development of the test method and test strategy, initial trialling of which took the form of round-robin tests performed by all participants on simulated workplaces at the IFA. The concept was fine-tuned during this process, and then evaluated. Where permitted by capacity, initial measurements have already been performed in the second stage by means of the agreed method at workplaces in France, Poland and Germany.
Comprehensive workplace measurements are to be planned for performance in a follow-on project: these are to deliver an adequate volume of data from which generic workplace protection factors for respiratory protective devices can be defined. Plans are for the work performed to date to be published in the coming year in the Annals of Occupational Hygiene.
-cross sectoral-Type of hazard:
personal protective equipmentDescription, key words:
respiratory protective devices (RPD), workplace protection factor (WPF), respirators performance, total inward leakage