In industries such as the mining, petrochemistry or power industries, personal protective equipment is often used in explosive atmospheres. What causes the occurrence of explosive hazards is ever-present in the work environment they include, electrostatic phenomena as well as the build-up of electrical charges on the surface of the protective equipment used. This paper presents the results of studies which were aimed at determining the fundamental electrostatic parameters of protective helmets as well as eye and face protection, surface resistance and the voltage of electrostatic fields. Examinations on the typical structure of the above mentioned equipment was conducted including the variable values of ambient humidity, which can occur in the working environment and with the use of various types of materials used to generate a charge. The adopted methods and testing equipment have been presented. Using the current, general requirements regarding the electrostatic properties of materials, the examined helmets and eye protection were assessed for their use in explosive atmospheres.
The use of individual fall protection equipment is one of the most commonly applied methods of protecting workers whose worksites are located above the floor level. The safety of the user in such a situation depends on both the proper selection and correct use of such equipment. Additionally, aspects such as minimizing the free-fall distance before the fall arrest, as well as quick notification of an accident and efficient rescue operation, are important factors influencing safety. This paper presents a new testing method for fall arrest equipment using a test stand consisting of the Hybrid III 50th Pedestrian ATD anthropomorphic manikin and measuring set with three-axis acceleration transducers. The proposed method and test stand were developed for the design and testing of new fall protection devices equipped with electronic detection and alarm systems, for which it is necessary to determine acceleration limits in order to determine the alarm threshold. The proposed method is based on the measurement of accelerations that occur during tipping and falling from the height of an anthropomorphic manikin secured by a self-locking device. Two places of attachment of the measuring set with a three-axis acceleration sensor were analyzed at the waist belt of the manikin (abdomen and back). Moreover, the self-locking device lanyard was attached to the two points of the safety harnesses (the front and back point). The aim of the research was to check whether the acceleration values depend on the places of attachment of the measuring and anchored system, as well as to determine their maximum values. Acceleration values corresponding to fall arrest and tipping were analyzed. Limits of acceleration have been established in order to determine the threshold of alarm triggering. The non-parametric Mann–Whitney U test was used to check whether the location of the three-axis acceleration transducer and the position of the self-locking device lanyard attachment affect the value of the recorded acceleration. For results of acceleration measurements when testing the behavior of the manikin during fall arrest, no statistically significant differences were found. For results of acceleration measurements when testing the tipping behavior of the manikin, statistically significant differences occurred. This means that during fall arrest, the location of the three-axis acceleration transducer and the position of the self-locking device lanyard attachment do not matter. This work is a continuation of previous research on accelerations characterizing human body positions occurring during normal physical activities (ADL—activities of daily living).
8 January 2009 in International Journal of Occupational Safety and Ergonomics
A full body harness is a component of personal systems protecting against falls from a height. To ensure users’ safety, the harness must retain its protective properties during its whole service period. All the elements of a harness (webbings, threads, metal buckles, etc.) are exposed to destructive factors. Harnesses stored and used for a few years were tested. The paper discusses the most frequent types of damage and their effect on the essential resistance parameters. The effect of atmospheric conditions, sunlight, mechanical damage and dust on the parameters of webbings was tested. Conclusions on the main causes of the loss of the protective properties of harnesses are drawn; periodic checks of the physical conditions and guidelines for estimating acceptable service time are recommended.
The article describes the importance of dimensional allowances, which are a consequence of the use of personal protective equipment (PPE) for work safety. The method of 3D scanning was proposed for determining the dimensional allowances which has been preliminary validated. Two geometric solids (a cylinder and a cuboid) were used to approximate the minimum space around the person using PPE. The solids are a simplified representation of the silhouette of a human subject performing activities in a confined work environment. They also correspond to the typical shapes of access openings and confined spaces, reflecting the real working conditions of welders, firefighters, mine rescuers, and other rescue teams. A detailed analysis of dimensional allowances for a full welding PPE set is provided. Based on the adopted parameters: the dimensions of the body, the base area and the volume, the differences in the dimensions of the body of a person dressed in underwear and in PPE were compared. The results of the presented studies indicate a significant role of dimensional allowances in interactions between persons wearing PPE and the work environment. The results are planned to be implemented in a new anthropometric atlas of human’s measures used for ergonomic design.
8 January 2009 in International Journal of Occupational Safety and Ergonomics
Retractable type fall arresters constitute a most effective group of components used in personal protection systems protecting against falls from a height. They are designed primarily for outdoor use, which results in exposure to atmospheric factors associated with risk of corrosion of metal elements. This paper presents the results of a study, in which retractable type fall arresters were exposed to a simulated corrosive environment, a neutral salt spray. It discusses the development of corrosion processes depending on the duration of exposure to corrosive conditions. Tests demonstrated that corrosion of elements decreased their strength and impaired the functioning of mobile parts. The article presents methods of testing the correct functioning of devices, necessary for assessing their resistance to corrosion, which have been developed for this purpose. It also analyzes the correlation between corrosion-related damage of retractable type fall arresters and potential hazards for their users.