Abstract:

The use of inappropriate working and protective clothing may cause significant electrical charging of both the clothing material and the wearer’s body. Static charge generation on the human body is especially dangerous because of its relatively high electrical conductivity, which may result in high-energy spark discharges. The respective procedures for risk evaluation and/or protection effectiveness may sometimes be questioned, mainly because it is impossible to exactly reproduce in the laboratory the systems that appear when the clothing is worn and, which follows on, there are no sufficient reasons to make generalizations with regard to conclusions. This especially concerns some international standards as well as publications describing the measurement methods of the charge decay time and the charge transfer in electrostatic discharges from textile surfaces. These methods are recommended, first of all, for the testing of atypical textile materials, such as those containing fibres with a conductive core. A method which creates the environment for a rational evaluation of both the level of risk caused by the clothing electrification and the effectiveness of protection provided, regardless of the predicted area of application of the product in question, was developed as a result of research carried out by the Institute of Industrial Organic Chemistry. The results of tests performed, in accordance with a specific procedure in extreme laboratory conditions, simulating the situations that cause the charging of the clothing material and the wearer’s body allow adequate quality classification and qualification for use of protective clothing in view of the static control requirements.