In order to prevent accidents involving fire and explosions due to the accumulation of heat during the self-decomposition of stored chemical materials, it is important to understand the thermal behavior of stored materials under an adiabatic condition. Recently, a differential-type adiabatic calorimeter (DARC) has been developed. However, the application range of the DARC in a thermal hazard evaluation is not fully understood. Therefore, in order to understand the application range of a DARC in a thermal hazard evaluation, the thermal behavior of di-tert-butyl peroxide (DTBP)-toluene solution and DTBP decomposition were measured. The results measured by the DARC were compared with those of an Accelerating Rate Calorimeter (ARC). As a result, the DARC is considered to be effective in a thermal hazard evaluation for a small exothermic reaction of less than 100 J/g, which is difficult to evaluate by ARC. In contrast, a DARC should not be used for the thermal hazard evaluation of the material that has a large reaction heat and vapor pressure.

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An advantage of Japan is that high-quality safety management and production technologies have been implemented at worksites by workers, managers and production engineers. If European technologies and social systems for safety of machinery are appropriately implemented on the basis of these “onsite capabilities,” a new technology and social system framework based on Japan’s own onsite capabilities may be created. This study examined the laws, regulations, and social systems that are favorable for safety of machinery in Japan. In maximizing onsite capabilities for safety management, the following four activities were presumed important: (1) the positioning of safety as an investment for new value creation, not a cost; (2) the sharing of a strong sense of ownership and common values for building a safe workplace among involved individuals; (3) the changes in strategies from prevention of recurrence to proactive prevention and from considering the number of accidents to considering the severity of accident; and (4) the consideration of unexpected problems. In addition to the aforementioned activities, the basic principles of machine safety and accident prevention in Europe were considered particularly important for spreading and promotion among corporate executives and machine designers. These principles are the (1) risk reduction strategies provided by the International Organization for Standardization (ISO 12100); (2) conformity assessments that use a modular approach and marking aimed at conveying information about declarations of conformity; (3) validity confirmation when using a machine based on marking information; and (4) feedback regarding disaster information for the design and manufacturing stages of a machine.

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[in Japanese]

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We performed a parallel measurement using some commercially available WBGT measuring instruments and compared the measurement accuracy among them in summer outdoor environments. The results showed that the simple models without globe thermometer were inaccurate for measuring outdoor environmental heat stress. Therefore, use of simple models without globe thermometer is not recommended outdoors or indoors with solar radiation. Also use of a simple conversion table for WBGT values should be avoided in outdoor environments with solar radiation if the table is based on air temperature and relative humidity.

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Electrostatic charges and/or discharges on powders bring about ignition and explosion of powders. Electrostatic problems that occur on powders must be taken care of in the industry. We have developed an electrostatic field sensor which measures electrostatic hazards. This sensor was supplied with compressed air, in order to protect powder particles from getting into it. This paper is related to how the compressed air affects the performance of the electrostatic field sensor. As a result, the performance of the electrostatic field sensor was affected by the compressed air. Namely, the experimental and theoretical values were not the same. This is because movement of the choppers inside the electrostatic field sensor was disturbed by the compressed air.

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The purpose of this study was to investigate the naming of manual material handling equipment (MMHE) and its use in small and medium-sized Japanese retail enterprises, using a questionnaire survey. The questionnaire was distributed to 2,543 enterprises, of which 694 responded. We found that a typical hand truck with one wing was used by almost all of the enterprises, whereas a roll box pallet was used only by about 40% of these enterprises. Also, a two-winged hand truck, a hand truck with two shelves and a dolly were used by approximately 30% of these enterprises. We also observed that these MMHEs were named differently in different enterprises and therefore people could not answer the survey correctly. This meant that it was impossible to use occupational accident reports to judge the types of MMHE according to their potential to cause accidents and we also could not understand whether the accident was caused by flaws in the distinctive features of each MMHE. From these results, it was evident that all the retail enterprises should be informed of the formal and popular names of these MMHE, which may lead to more concrete measures for acquiring the necessary data. We also asked about their subjective danger when working with MMHE, and whether or not the enterprises had MMHE manuals. We found that the enterprises perceived the danger as generally low and that only approximately 10% actually had manuals. These results suggested that it was necessary to provide a worker’s manual to these companies in order to recognize the hazards in working with MMHEs.

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[in Japanese]

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