Depending on the concentrations that alcohol reaches in the blood, there are well-known effects on the nervous system and on the body in general. These effects are summarized in Table 3, with particular emphasis on the consequences of small doses for what concerns driving the car or the use of dangerous equipment for oneself and others. In fact, the legislation of European countries (and the vast majority of countries in the world) establishes a limit of 0.5 g per liter of blood: beyond this limit it is strictly forbidden and punishable to drive a car. But it is to be taken into serious consideration that already at values of 0.2 g per liter (less than half then) there is a more swaggering behavior, which leads to underestimating the dangers and overestimating one’s own abilities.
Finally, a very small percentage of ethanol (2-10%) is eliminated unaltered through lungs, urine, sweat, etc .; it is precisely by using this elimination system that non-invasive tests (balloon) can be carried out which allow to evaluate the share of alcohol present in the blood (alcoholemia). The concentration of ethanol in the blood therefore depends on various factors: the amount ingested, the method of intake (fasting or meal), the body composition, weight, sex, genetic factors, the amount of body water, the capacity individual to metabolize alcohol, from habit to alcohol. Women, having a lower weight, lower quantities of body water and lower efficiency of the alcohol metabolism mechanisms, are more vulnerable to its effects and, for the same consumption, have a higher alcohol content.