Microclimate. Hygienic normalization of microclimate parameters of production and non production workplace.

The normalization of microclimate parameters of production workplaces.

The standards of production microclimate are established by the system of labour safety standards of the State Standard 12.1.005-88 "Total sanitary-hygienic requirements to the working zone air" and SANPIN 2.24.548-96 "Hygienic requirements to microclimate of production workplaces". They are united for all productions and all climatic zones with some small retreats.

In these standards each microclimate component in working zone of the production workplace is separately normalized: temperature, relative humidity, velocity of the air in depending on abilities of the person organism to acclimatization in different season, type of the cloth, intensities of the produced work and type of heat generations in workplaces.

For estimation of the cloth type (heat insulation) and acclimatization of the organism in different season the concept “year period” is introduced. It is distinguished the warm and cool period of the year. The warm period of the year is characterized by average daily temperature of the outside air +10^oС and above, cool period of the year is characterized by average daily temperature -below +10^oС.

At the taking account the intensity of the labour all types of work, proceeding from the total expenses of organism energy, are divided on three categories: light, average gravity and heavy.

Works carried out in the sitting or standing position, not requiring the systematic physical tension (comptrollers’ work, work in processes of precision instrument-making, office works and others) are concerned to the light works (category I) with energy expenses up to 174 Wt. Light works are divided on the category Iа (energy expenses up to 139 Wt) and category Ib (energy expenses 140... 174 Wt).

Works with energy expenses 175...232 Wt (category IIа) and 233...290 Wt (category IIb) are concerned to the average gravity works (category, II). Works, related to permanent walking, carried out in the sitting or standing position, but not requiring loads displacement are included in category IIа, works related to walking and carrying of small (up to 10 kg) loads (in machine-assembly departments, textile production, wood processing and others) are included in category IIb.

Works related to the systematic physical tension, particularly to the permanent movement, transportation of big loads (over 10kg) (in the forge casting shop with manual processes and other) are concerned to the heavy works (category III) with energy expenses over 290 Wt.

According to the intensity of the heat generation the production workplaces are divided on the groups depending on the specific excesses of explicit heat. Explicit heat is the heat influencing on the variation of workplace air temperature. Excess of explicit heat is the difference between summary inflows of the explicit heat and summary heat loss in the workplace.

The explicit heat that was formed within workplace, but was removed from it without transmission of the heat to the air of workplace (for example, with gas from flue or with the air of local suctions from equipment) at calculation of heat excess is not taken into account. The small excesses of the explicit heat is the heat excesses not exceeding or equal to 23 Wt on 1 m³ of internal volume of the workplace. Workplaces with big excesses of the explicit heat are characterized by heat excesses more than 23 Wt/m³.

The intensity of the heat irradiation of workers from warmed surfaces of the technological equipment, lighting instruments, insolation on constant and changeable work places must not exceed 35 Wt/m² at irradiation 50 % of surface of the person and more, 70 Wt/m² - at irradiation 25...50 % of surface and 100 Wt/m² - at irradiation not more than 25 % of surface of the body.

The intensity of the heat irradiation of workers from opened sources (the heated metal, glass, open flame and others) must not exceed 140 Wt/m2, not more than 25% surfaces of the body must be under irradiation and it is obligatory to use the individual protection funds.

In the working zone of the production workplace according to the State Standard 12.1.005-88 the optimum and possible microclimate conditions can be established.

Дата добавления: 2023-11-30