The border between products S-and M-classes, apparently, is rather conditional as it is difficult to establish its strict quantitative characteristic. For example, it is possible to carry products in weight to a class of M no more than 200 grams, and it is possible and 100 or 300 grams. Concrete value of weight in this case does not play a defining role, though and it is obvious, that reduction of weight and dimensions of the self-rescuer raises probability of its constant carrying by the person. Rough value of the specified probability depending on weight and dimensions of products can be received by a method of an expert estimation with attraction as experts of various groups of the population.

Basic distinction between self-rescuers of considered classes the approach to a substan-tiation of requirements to products should be. For samples of class S protective properties should be priority, hence, requirements to them can be formed under the classical scheme allocation of typical situations in which it is required application of products; an estimation of quantitative characteristics of amazing factors in these situations; definition of parameters of the protective properties providing reliable protection of the person in the most adverse conditions. The further development of products should be directed on search of the designs, allowing to realize demanded protective properties at minimally possible manydimensional characteristics and costs of samples.

At a substantiation of requirements to self-rescuers of a class of M, in our opinion, other approach should be used. Operational properties of products, first of all their suitability to constant carrying in a pocket of clothes, in a handbag, in a special case, etc. In other words should be priority, on weight and dimensions it there should be products of type of a mobile phone, a case for glasses a wallet or a harmonious umbrella. Does not cause doubts, that at restriction of weight and dimensions of products it is not obviously possible to realize in full in them protective the properties, defined in requirements for samples of class S. In this connection there is a problem of definition of admissible levels at which products of a class of M it is possible to consider effective and successfully carrying out a problem in the applicability.