Occupational risk assessment of passenger bus drivers

The aim of this work is improving the procedure for professional risk assessment of passenger bus drivers, taking into account ergonomic, psychosocial, individual, and hygienic factors. To develop the methodology for assessing the professional risk of drivers the theory of analysis was used, which allows to establish alternative solutions of the problem by determining an integrated criterion that depends on a number of individual indicators characterized by ergonomic, psychosocial, individual, and hygienic factors influencing the working conditions of the passenger bus driver. A checklist has been developed to quickly assess the occupational risk of passenger bus drivers, which takes into account the impact of several harmful production factors that contribute to the creation of unfavorable conditions for the occurrence of occupational diseases.  A feature of this approach is the ability to distinguish the level of risk for each harmful production factor and determine the overall level of occupational risk. It is recommended to reduce the effect of occupational risk on the driver of a passenger bus to improve the system of medical examinations, the system of admission to the vehicles driving in the implementation of passenger traffic and strengthen control over the technical condition of vehicles. The relationship between the integrated criterion of occupational risk of the driver and indicators that are characterized by ergonomic, psychosocial, individual, and hygienic factors, which are formed by the working conditions of the driver in the carriage of passengers. As a result, a new approach (checklist) is proposed, which can be used in trucking companies without any additional equipment after training in testing

Оцінка професійних ризиків водія технологічного вантажного автомобіля для умов лісового господарства

Мета роботи: удосконалення процесу з визначення рівня професійного ризику водія технологічного вантажного автомобіля, шляхом визначення взаємозв’язків між різними зовнішніми і внутрішніми небезпечними чинниками, які підвищують вірогідність настання незвичайної події під час виконання виробничої діяльності. Метод: застосовувався метод fuzzy “Decision Making Trial and Evaluation” (fuzzy Dematel). Теоретична цінність дослідження: визначено тридцять небезпечних чинників, що можуть призвести до порушення опорно-рухового апарату водія технологічного вантажного автомобіля під час виконання трудових зобов’язань на підприємствах лісного господарства. Визначено найбільш впливові небезпечні чинники нечітким методом “fuzzy DEMATEL”, які мають найбільш вплив на настання небезпечної події, що пов’язання з роботою водія технологічного вантажного автомобіля. Практична цінність дослідження: встановлено причино-наслідковий взаємозв’язок між визначеними небезпечними чинниками, які впливають на роботу водія технологічного вантажного автомобіля під час виконання професійної діяльності, що дозволяє ідентифікувати причинні та наслідкові небезпечні чинники. Цінність дослідження: розроблено алгоритм оцінки професійних ризиків з урахуванням

Study of protective efficiency of respirator with forced air supply

The aim of the work was to conduct experimental studies aimed at determining the protection factor of the filter respirator with forced air supply by volunteers in different modes of operation and to establish the dependence of the amount of air supplied by the fan from the air purification device to the filter’s resistance. Simulation studies to determine the protective effectiveness of the filter respirator on the testers were performed according to the procedure for determining the penetration coefficient of test aerosol – sodium chloride, as the ratio of the submask concentration of test aerosol to the ambient concentration formed in a special chamber that meets the requirements of DSTU EN 13274. Determination of the amount of air supplied by the air purification unit to the submask space and assessment of the value of positive pressure inside the mask was performed according to the procedure described in DSTU EN 12941: 2004. As a result of simulated laboratory tests to determine the protective effectiveness of filter respirators with forced air supply to the testers, it was found that the average result of the protection factor of the test samples ranged from 99.93 to 99.97, which meets the requirements of DSTU EN 12941: 2004. In addition, it was found that the amount of air treated by the fan of the air purification device for clean filters is 165 and 215 dm3/min for operating modes “Normal” and “Turbo”, while for the polluted filters it is reduced to 131 and 185 dm3/min, respectively. During the study, the compliance of the value of excess pressure in the submask space with the requirements of DSTU EN 12941: 2004, which should not exceed 2.5 mbar, was confirmed. It is also determined that the stability of the technical parameters of the air purification device is maintained in the specified range when charging the “Dinogy Li-Pol 11000mAh 14.8V 4S 25C” brand battery not less than 12 V to ensure the current value of not less than 1.6 A. The practical value of the results lies in determining the duration of protective action of the filter respirator, the choice of filter resistance to establish the scope and modes of operation in the developed personal respiratory protection equipment

Analysis of pressure difference changes in respirator filters while dusting

Objective is to determine the relation between pressure difference of a filter and parameters of a filtering layer to lengthen the protection period. The study involved elements of system analysis and mathematical modeling. Basic statements of the theory of nonstationary filtration and aerohydrodynamics were applied to develop a dust-loaded filter model. Dependence of pressure difference in a filter upon certain changes in packaging density of dust-loaded fibers has been determined; the dependence makes it possible to define minimum fiber packaging density to provide maximum dust capacity. To provide maximum dust capacity and high protective efficiency, the number of filtering layers in multilayered filters depends upon dust concentration within the air of the working zone, specified protection level of a respirator, air loss, and maximum dust volume which may be accumulated in the finishing filtering layer in terms of fiber packaging density being determined according to the minimum pressure difference in a filter at final time of respirator operation. A model of changes in pressure difference in filtering respirators in the process of aerosol particles depositing on filters has been improved; contrary to other available models, that one takes into consideration changes in fiber packaging density while dusting, filtration coefficient, and the amount of aerosol particles

Analysis of pressure difference changes in respirator filters while dusting

Objective is to determine the relation between pressure difference of a filter and parameters of a filtering layer to lengthen the protection period. The study involved elements of system analysis and mathematical modeling. Basic statements of the theory of nonstationary filtration and aerohydrodynamics were applied to develop a dust-loaded filter model. Dependence of pressure difference in a filter upon certain changes in packaging density of dust-loaded fibers has been determined; the dependence makes it possible to define minimum fiber packaging density to provide maximum dust capacity. To provide maximum dust capacity and high protective efficiency, the number of filtering layers in multilayered filters depends upon dust concentration within the air of the working zone, specified protection level of a respirator, air loss, and maximum dust volume which may be accumulated in the finishing filtering layer in terms of fiber packaging density being determined according to the minimum pressure difference in a filter at final time of respirator operation. A model of changes in pressure difference in filtering respirators in the process of aerosol particles depositing on filters has been improved; contrary to other available models, that one takes into consideration changes in fiber packaging density while dusting, filtration coefficient, and the amount of aerosol particles

Analysis of pressure difference changes in respirator filters while dusting

Objective is to determine the relation between pressure difference of a filter and parameters of a filtering layer to lengthen the protection period. The study involved elements of system analysis and mathematical modeling. Basic statements of the theory of nonstationary filtration and aerohydrodynamics were applied to develop a dust-loaded filter model. Dependence of pressure difference in a filter upon certain changes in packaging density of dust-loaded fibers has been determined; the dependence makes it possible to define minimum fiber packaging density to provide maximum dust capacity. To provide maximum dust capacity and high protective efficiency, the number of filtering layers in multilayered filters depends upon dust concentration within the air of the working zone, specified protection level of a respirator, air loss, and maximum dust volume which may be accumulated in the finishing filtering layer in terms of fiber packaging density being determined according to the minimum pressure difference in a filter at final time of respirator operation. A model of changes in pressure difference in filtering respirators in the process of aerosol particles depositing on filters has been improved; contrary to other available models, that one takes into consideration changes in fiber packaging density while dusting, filtration coefficient, and the amount of aerosol particles

Studying the efficiency of a complex individual protective device

Objective is to study efficiency of a complex protective device including coefficients of penetration and suction of aerosols for dust half-masks of various designs. The half-masks were tested experimentally on specially designed laboratory stands with the help of volunteer-testees; the tests included specifications according to EN 149, EN 352-1, ISO 6942. The studies have demonstrated that a complex protective device for workers is rather efficient providing average coefficient of suction being 1.5% that is almost by 30% less than the values of standard filtering respirators of similar protection class. Noise attenuation within the range of 4000 – 8000 Hz is from 19 to 26.7 dB; within the range of speech frequency (0.5÷2.0 kHz), acoustic efficiency is up to 8÷16 dB helping preserve the possibility of communication and timely reaction to warning signals. Use of thermal protecting elements makes it possible to reduce temperature of head heating by 80% comparing to the results obtained without the protective device application. The developed balaclava with the built-in dust respirator and hearing protection devices may be used in the context of the corresponding filter class up to 12 MAC in terms of the most hazardous aerosols, when noise level is up to 14 dB within 2000 – 8000 Hz frequency range; moreover, it provides slow temperature rise up to 2 ºС per minute

Evaluation of the probability of miners’ protection while using filtering respirators

Objective of the research is to evaluate the probability of deterioration of the protection of miners’ respiratory organs while using filtering respirators in terms of coal mines under the coal mine conditions and to elaborate recommendations for the reduction of possible occupational disease risks. A Markovian process theory has been applied to solve the formulated problem. It has been determined that the probability of deterioration of the protection of a worker wearing a filtering respirator is up to 50%, which is stipulated by the lack of corresponding training as for the correct filtering respirator use, negligence of the physical load and its duration during the respirator selection, and possible mistakes during its operation. Reduction of the occupational disease risks is possible only in terms of the use of high-quality filtering respirator under conditions of its correct selection, maintenance and use by the trained miners with the preliminary checking of its relevance to the coal mine conditions. It has been shown that the development of a respiratory protection programme at an enterprise is the efficient tool to provide a miner with high-quality and appropriate filtering devices for the respiratory protection

Selection of Effective Filter Respirators. Challenges and Opportunities

The aim of this paper is to reveal the possibilities to ensure the choice of quality filter respirator that meets the working conditions and anthropometric parameters of user. It is established that the critical issues to ensure reliable protection of user during the performance of professional activities with the use of devices of individual protection of respiratory organs, which are not disclosed (not reflected) by the relevant regulations, the procedure of risk assessment, based on work conditions, verification of compliance of the filter respirator half-mask to anthropometric parameters of user's face, taking into account the duration of filters protective action. It is shown that according to the normative acts of the organization for the assessment of the risks of occupational diseases both in the choice and operation of filter respirators is the responsibility of the employer, and the monitoring of faithful implementation of the recommendations on the effective use of filter respirators must be carried out by the departments of labor protection of the enterprise. It is proposed to assess risks of occupational diseases during the selection and operation of the filtering respirators one of the methods in accordance with the requirements of DSTU IEC/ISO 31010:2013. The recommendations on elimination of possible mistakes during this process to reduce the risk of occupational disease are provided. The new classification of filtering means of individual protection of respiratory organs was developed, which allows carrying out selection taking into account the peculiarities of conditions of work. It is shown that by using thermography of obturate band of filter respirator half mask, you can set it according to anthropometric parameters of the userʼs face. It is recommended that you replace the filters or on the basis of calculation of term of protective action under the conditions or by using filters with active/passive indicators