scope:

This standard defines sampling conventions for particle size fractions which shall be used in assessing the possible healthy effects of airborne particles in the workplace. They are derived from experimental data for healthy adults. Conventions are defined for the inhalable, thoracic and respirable fractions; extrathoracic and tracheobronchial conventions may be calculated from the defined conventions. The convention chosen will depend on the region of effect of the component of interest in the airborn particles. Conventions are stated in terms of mass fractions, but they may also be used when the intention is to evaluate the total surface area or the number of particles in the collected material. In practice, the conventions will often be used to specify instruments to sample airborn particles for the purpose of measuring concentrations corresponding to the defined fractions. It should be noted that experimental error in the testing of instruments, and possible dependence on factors other than aerodynamic diameter, mean that it is only possible to make a statement of probability that an instrument's performance falls within a certain range, and that different instruments will fall within an acceptable range. One application is the comparison of mass concentration of airborne size fractions with limit values. It should be noted with respect to relevant European Directives that the use of other methods is allowed provided that they yield the same or stricter conclusion.