Traditional safety is based on the categorical imperative is to ensure the safety, to prevent any accidents. In practice, such a concept is inadequate to the laws of the technosphere. A requirement for absolute security, wins its humanity, can turn into a tragedy for the people because, to ensure zero-risk in current systems it is impossible.

The modern world has rejected the concept of absolute security and came to the concept of acceptable (valid) risk, the essence of which in pursuit of such security, accept that society in a given period of time.

Public perception of risk and danger is subjective. People sharply react to events rare, accompanied by a large number of one-time victims.

At the same time, frequent events, resulting in the die unit or a small group of people, not cause such intense relationships. Daily production dies 40-50 people, in the whole country from various dangers lose their lives more 1000 people a day. But these details are less impressive, than death 5-10 people in a single accident or any conflict. It must be borne in mind when considering the problem of acceptable risk. Subjectivity in risk assessment confirms the need for search techniques and methodologies, deprived of this drawback. According to experts, the use of risk as hazard evaluations is preferred, than using traditional indicators.

Acceptable risk combines technical, economic, social and political aspects and represents a compromise between level of security and the possibilities of its achievement.

First of all you need to keep in mind, that economic opportunities improve the security of technical systems are not unlimited.

Spending excessive funds to increase security, you can damage the social sphere, for example to degrade medical care.

With increasing costs, technical risk is reduced, but growing social. Total risk has a minimum at a certain ratio between investments in technical and social spheres. This circumstance and you need to consider when choosing a risk, with which society is forced to tolerate.

In some countries, for example in Holland, acceptable risks established in the legislative order. The maximum acceptable level of individual risk of death is generally considered 10^-6 a year. Dismissive is considered a small personal risk of death 10^-8 a year.

The maximum acceptable risk for the ecosystem is the one, whereby may suffer 5% types of biogeocenosis.

Actually acceptable risks 2-3 order "stricter" actual. Therefore, introduction risk is an acceptable action, directly aimed at the protection of human.