BS 5295-1:1989

Foreword
Committees responsible
Specification
1 Scope
2 Definitions
3 Designation of environmental cleanliness
4 Air pressure
5 Filtration
6 Certification of compliance
Appendices
A Illustration of particulate content limits for
   designated classes of environmental cleanliness
B Method of test for the determination of pressure
   differences
C Method of test for the determination of filter
   installation leaks
D Method of test for the determination of induction
   leaks from construction joints
E Method of test for the determination of particulate
   contamination by microscopic sizing and counting
Tables
1 Comparison with classes of 1976 edition
2 Requirements for controlled environment installations
3 Maximum permitted concentration for filter
   installation leaks
4 Minimum challenge aerosol concentrations for
   induction leak testing
5 Maximum permitted concentration for induction leaks
6 Factors and grid squares to be used in estimating
   total particle counts
Figures
1 Maximum number of particles of a given particle size
   for designated classes of environmental cleanliness
2 Calibration of the measuring eyepiece
3 Reduced unit area

Ten classes of environmental cleanliness according to level of particulate content. For industrial medical and pharmaceutical fields. Test methods for control of particulate content are given in appendices. See also PD 6609.