Occupational injury rate of Korea recently slides slightly downward after stagnating around 0.7%'s for more than 10 years. To accelerate this trend ,injury prevention for small enterprises is crucially important because vast majority of injuries take place in small enterprises. Considering huge number of small enterprises, we need to focus our efforts to type of riskier industries. By analysing detailed injury data, we select type of industries which need our concentrated prevention efforts.Several preventive measures are recommended, after we made literature survey of case studies for small enterprises.The result identifies riskier type of industries including transportation machinery manufacturing industry type(B),woods & veneer manufacturing industry, etc. Safety of machinery, new enterprises less than 2 years in service and new employees serving less than 6 months are in need for focused prevention efforts. To cope with these vulnerable spots, recommended preventive measures include strengthening of machinery safety standards,early assistance for safety to new enterprises, mandatory safety education before employment, etc.

Forklift truck is a very convenient transportation vehicle and widely used in industries. However, a lot of overturn accidents occur during operation because of poor understanding on the stability of forklift trucks. The stability of a forklift is defined by the minimum slope of the ramp where a forklift truck overturns. According to the KS BISO 22915-2 code, the stability is determined from the four kinds of stability tests. The equations for the stability of a forklift truck were proposed already in several published literatures and the equations can be used conveniently to estimate the stability and examine the effects of design parameters in forklift trucks. However, because the detail derivation procedure was omitted, it is very difficult to examine the accuracy of the proposed equations and to modify the equations for other types of forklift trucks. In this paper the stability equations were derived again with detail derivations for the four kinds of stability tests. And the effects of acceleration or centrifugal forces were also additionally included in the equations and minor corrections were also made.

-There have been large explosions at some chemical plants recently. Accidents in chemical plants have been caused mainly by servicing for maintenance. There is a need to find a key target for effective injury prevention in maintenance. In this paper, facilities were selected as a key target and the risk priority numbers of the facilities were calculated in order to prioritize preventative measures.The research method was based on the followings; the list of the facilities is found through injury analysis. Then, the risk of each facility was calculated by the frequency of accidents and the working day loss through injuries. In addition, the risk of the facilities was calculated again by the frequency and the severity based on knowledge and experience of experts.As a result, the facilities in chemical plant maintenance are ranked in order of high to low risk priority number; reactor, dryer, tank lorry, etc. In the future, special measures and attention should be directed according to the risk priority number during the maintenance of chemical plants.

There has been an increase in fire/explosion accidents caused by chemical substances used in new small/medium sized construction, reconstruction, or extension sites. There is vast room for improvement, especially in safety training, safety inspection, and selection of countermeasures because training, technicality, and management systems regarding fire·explosion risks in small/medium sized construction sites are very immature in most cases. The purpose of this study is to propose a differentiated technical, educational, and management application plan for preventative management of fire·explosion accidents caused by chemical substances used in small/medium sized construction sites.

Electrical apparatuses for use in the presence of explosive gas atmospheres have to be special designed to prevent them from igniting the explosive gas. Flameproof design implies that electrical components producing electrical sparks are contained in enclosures and withstand the maximum pressure of internal gas or vapours. In addition, any gaps in the enclosure wall have to designed in such a way that they will not transmit a gas explosion inside the enclosure to an explosive gas or vapours atmosphere outside it. In this study, we explained some of the most important physical mechanism of Maximum Experimental Safe Gap(MESG) that the jet of combustion products ejected through the flame gap to the external surroundings do not have an energy and temperature large enough to initiate an ignition of external gas or vapours. We measured the MESG and maximum explosion pressure of propane and acetylene by the test method and procedure of IEC 60079-20-1:2010.When the minimum MESG is measured, the concentration of propane, acetylene in the air is higher than the stoichiometric point and their explosion pressure is the highest value.