[en] The technique providing the use of the clothes' model is proposed for the investigation of the principles of the interchange of air between the space under protective coating and environment. The model completely fitting the clothing design and its air permeability was made of filtering material practically impermeable for aerosols. In this case for those exposed to radioactive aerosols the contamination of the space under protective clothing measured with a radiometre, can be attributed only to the air penetrating the design looseness of the clothes