The article presents results of the granulometric composition of chip particles when sanding wood (beech) and wood-based materials (particleboard and semi-hardboard) using different types of sanders – wide belt sander, narrow belt sander, and hand sander. On the basis of the carried out sieve analyses, the proportion of produced particles, which can be marked as dust with the particle size of ≤ 80 μm, is high at the interval from 89.21% - 96.29 %. The highest percentage of dust particles was reached at dust from the hand disk sander. At the end of the article we point to possible technical safety measures – additional dust exhausting, suction, to possibly reduce the dust getting to the working environment.

The paper deals with determination of the medical fitness of drivers. They were psychologically tested with particular emphasis on visual perception. The research included visual perception - spatial vision and adapting to the darkness with the aim to show impact of age and education of the respondents to obtained results. The study included truck drivers, bus drivers and people with pre-test candidates and checking on driving instructors or examiners.

Electricity is the most important form of household energy and one of the most important forms of energy for industry and transport. Electrical distribution in construction and transport is almost exclusively implemented using electrical cables. One of the unresolved problems associated with electrical cables is the release of smoke and the resulting reduction of visibility in case of fire in the area. In this study, a new approach was developed to assess the reduction of visibility in an area affected by an electrical cable fire. This approach is based on the determination of the critical ratio of smoke volume (in the smoke layer and exhausted from the fire compartment) to the length of the burning cable, through which the visibility of reflective and illuminated signs was reduced to a lower limit value (a standard of 10 m). The input data for this approach was the extinction area of the smoke released from one meter of burning cable and the length of the cables in the area. This approach was used to test two power cables (CHKE-V J3x1.5 and CHKE-R J3x1.5) and one signal cable J-H(St)H 1 × 2 × 0.8 with the B2ca, s1, d1, a1 fire reaction class. The smoke extinction area of the examined cables was determined using a cone calorimeter at a heat flux of 50 kW/m2. The obtained data showed that in order to maintain a visibility of 10 m for reflective signs, the critical ratio of smoke volume to length of burning cable was 7.5 m3/m. For illuminated signs, the critical ratio was 2.8 m3/m. The relationship between burning length and visibility allows the calculation of visibility in the fire compartment affected by cable fire only from cables length.

The paper assessed the fire risk of the summer tyres marks Kormoran on the base of thermogravimetric analysis complemented by the analysis and determination of the carbon monoxide (CO) concentration in the decomposition products. Thermogravimetric analysis was performed in an atmosphere of air with flow rate of 4 l/min. During the thermal analysis, the samples were loaded with temperatures from 20 to 550 °C, in the first case by rate of heating 5 °C/min and in second case by 10°C/min. The results of thermal analysis shown that the thermal decomposition of the samples at a heating rate of 5 °C/min started at 320 °C and from the temperature of 370 °C thermal decomposition pass intensively. At a heating rate of 10 °C/min, thermal decomposition of the samples started at 360 °C, from the temperature of 420 °C thermal decomposition pass intensively. The measured concentrations of CO in combustion gases showed that the thermal decomposition of tyres is accompanied by a significant release of gas. The results also shown that the thermal decomposition of the investigated tyres coupled with the release of CO starts at temperatures around 320 °C. That temperature cannot be considered as safe in the medium and long-term exposure.

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