BS EN 481:1993 PDF

1   Scope This standard defines sampling conventions for particle size fractions which are to be used in assessing the possible health effects resulting from inhalation 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 inhalable fraction is sometimes called inspirable — the terms are equivalent. The nomenclature of the fractions is discussed in Annex A.) Assumptions are given in clause  4 . The convention chosen will depend on the region of effect of the component of interest in the airborne particles (see clause  3 ). 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 airborne 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.

NOTE The problem of comparing instruments with the conventions is to be...