Temperature limit values for gripping cold surfaces

Objectives. At the request of the European Commission and in the framework of the European Machinery Directive, research was conducted jointly in five different laboratories to develop specifications for surface temperature limit values for the gripping and handling of cold items. Methods. Four hundred and fourteen experiments were run where male and female subjects were invited to grip for up to 20 min cold bars of different contact coefficients, i.e. polished wood, nylon, stone, steel and aluminium. The air temperature and the bars" initial surface temperatures ranged between 0 and -30degreesC for the various experiments. While gripping the bars, either only the hand or the whole body was exposed to cold. Results. The data were used to develop a prediction formula and a graph of the surface temperature limit values in order for the skin contact temperature not to reach <15degreesC. This duration is shown to offer a significant degree of safety with respect to the minimal surface temperature spontaneously tolerated by the subjects. Conclusions. Experiments and modelling must be pursued to extend these data to other conditions of exposure.