Nowadays there is a complex of approaches aimed at prevention of the impact of harmful chemical substances on workers in a working zone. Among them such measures as reducing concentrations of hazardous chemical substances and diet correction.

Today 2457 maximum-permissible concentrations of toxicants are enlisted in Kazakhstan. For many chemical substances, however, there are no approved methods of their analysis therefore the control over them is impossible. But the main problem is that most of the regulations were adopted in past and do not live up to the current situation.

In particular, let us consider some hydrocarbons. At a great number of productions the workers have contact with alkanes and these particular compounds form the basis for any oil. Hexane, an alkane hydrocarbon, is a basic constituent of gasoline. Due to its easy evaporation this particular compound of gasoline accounts for air pollution.

The analysis of available data about hexane impact on the organism speaks in favour of additional research because there is practically no accurate data on its action threshold level. At present maximum concentration level of hexane in the air of the working zone is 300 mg/m3. However according to American and Japanese scientists half of the workers, after 6 years of industrial contact with hexane in concentration of 190 mg/m3 complained on paresthesias in extremities, decreased tendon reflexes. Therefore maximum concentration level of hexane in the air of the working zone in the USA was reduced in 10 times - from 1800 mg/m3 up to 180 mg/m3.

Today there is a great deal of data concerning hexane action on the condition of the nervous system. To be specific, the cases of polyneuritis and loss of colour vision e.t.c. were reported. In experiments with animals the effects were observed of its impact on various ferment systems in lungs displayed as atelectasis and hypostases of lungs, changes in the monooxygenase system of the liver were revealed. Thus it is obvious, that hexane can be classified as a polytropic poison affecting absolutely different tissues of the organism. The frequent and intensive contact with this substance requires very serious attention. The above mentioned facts give evidence that reconsideration of maximum concentration levels for air in the working zone should be made.

Limitation of contact time with toxic gases enables the organism of the person to adapt to their influence. Nevertheless this approach is not adequately introduced, whereas the organization of production with regard to the time of contact enables to set a maximum concentration limit for the air in a working zone in compliance to this factor. Reduction of contact time is even more feasible especially when it is impossible to change the norms.

At industrial enterprises spreads the trend to carry out health improving measures for their workers. Such approach, undoubtedly, is highly recommended because the worker is considered not only in a context of harmful production influences but in a complex of industrial, home and ecological factors. It might result in a dramatic reduction of occupational and professionally induced diseases. In practice health improving measured are normally conducted when certain signs of disease are displayed and their development should be prevented. The diet correction of the impact of toxic chemical substances in workers was adopted by the Order of the Minister of Labour and Social Protection of the Population of Republic of Kazakhstan. As an effective means alimentary correction is recognized, which prevents assimilation of certain toxins in the organism. Combination of alimentary correction with the measures aimed at increasing the general resistance of the body enables to raise considerably the efficiency of alimentary correction of intoxications.

Therefore, to minimize the impact of toxic fumes on workers it is necessary to reconsider a number of maximum concentration levels, the measures preventing the contact to toxic fumes and shortening the time of exposure to them should be encouraged.

Undoubtedly, it is necessary to develop the practice of health improving measures at industrial enterprises. It is absolutely necessary to reconsider completely the approaches to diet correction of the exposures.