A clean room  is a room where the size and number per cubic meter of particles such as dust , microorganisms , aerosol particles and chemical vapors are maintained in the air within a certain specified range. Other parameters such as humidity, pressure and temperature can also be controlled if necessary. Such premises are generally constructed and used in such a way as to minimize the intake, generation and accumulation of such particles within the premises.

A clean room or a clean room is a room in which the countable concentration of airborne (aerosol) particles and, if necessary, the number of microorganisms in the air are maintained within certain limits.

A particle is understood as a solid, liquid or multi-phase object or microorganism with sizes from 0.005 to 100 microns. When classifying clean rooms, particles with lower threshold sizes from 0.1 to 5.0 µm are considered. The key factor is that clean rooms are characterized precisely by the countable concentration of particles, that is, the number of particles per unit volume of air, the dimensions of which are equal to or greater than a certain value (0.1; 0.3; 0.5 microns and_cc781905-5cde-3194-bb3b -136bad5cf58d_t. d.). In this they differ from ordinary rooms, in which the purity of the air is estimated by the mass concentration of pollution in the air. This implies the features of maintaining and determining purity indicators, specific requirements for control devices, particle counters in air, etc.