Study of The Impact of Users' Features on Dimensional Allowances Resulting from the Use of Personal Protective Equipment.

Up-to-date anthropometric data on the human population are needed for designing safe and ergonomically efficient workplaces. An important determinant of safety and ergonomic comfort at work is knowledge of the value of dimensional allowances (DAs) when using personal protective equipment (PPE) as the dimensions and space occupied by workers increase. This is particularly important in environments characterized by spatial constraints. However, it is not well known to what extent the aforementioned DAs are affected by the users' features. The anthropometric dimensions of 200 people (151 males and 49 females) were obtained from 3D scans, and these became the basis for calculating DAs when using PPE kits normally worn by rescue and technical workers. DAs were determined for the entire body shape of a person wearing three types of PPE kits designed for firefighters, mine rescuers, and welders. In the study, maximum and mean values of height, width, and circumference DAs were obtained. In addition, percentage dimensional increments (DIs) were calculated. A three-dimensional analysis of the human body with and without PPE, involving a 3D scanning methodology, was applied to address the research question. Test results clearly indicate that the values of DAs do not depend on the anthropometric features of users, such as sex, age, and body height percentile-they remain constant for a given type of PPE. The presented data are useful for designing PPE products as well as work tools and infrastructure, including machinery, devices, workstations, means of transport, interiors, and building equipment. The results of the presented study indicate that dimensional allowances play a significant role in interactions between persons wearing PPE and their work environments. The obtained results (DAs and percentage DIs) are included in a new anthropometric atlas of human measures developed by the CIOP-PIB in 2023.

Studies of Acceleration of the Human Body during Overturning and Falling from a Height Protected by a Self-Locking Device.

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).

Procedure for Determining Dimensional Allowances for PPE Using 3D Scanning Methods.

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.

Properties of thin coatings deposited by physical vapour deposition on safety helmets.

This article presents research on a new solution for industrial helmets improving mechanical and physical properties (temperature resistance and reflection of infrared radiation). The application of known technology in a new personal protective equipment area has been described in order to increase their level of safety and comfort of use. In this work we have studied the effect of a selected magnetron sputtering coating method onto polymer substrates, such as acrylonitrile-butadiene-styrene copolymer, polycarbonate, polyethylene, high-density polyethylene, polyamide, glass and silicon. Coatings made of copper, aluminium, TiN and TiAl were used. This work aims at identifying the best substrates for coating deposition improving the quality of protective helmets. On the basis of the obtained results, it can be stated that the TiN coating provides the best protection from infrared radiation and the best scratch resistance.

Analysis of selected mechanical parameters for foamed materials with non-Newtonian liquid characteristics in terms of their use in aspects of protective helmets.

This article presents the results of measurements of mechanical parameters for foamed materials with non-Newtonian liquid characteristics (energy suppressed in the sample, force transferred to the anvil during the dynamic tests). In dynamic studies, the following characteristics were determined: the pressure forces exerted on the anvil as a function of the sample deflection during the impact, the energy suppressed in the sample depending on the temperature and the energy suppressed in the sample depending on the sample density. Foamed materials with non-Newtonian characteristics are currently used as elements protecting against impacts. Such materials have been used for the first time in protective helmets, and in particular in those designed for workplace applications.

Mechanical properties of protective spectacles fitted with corrective lenses.

The majority of commercially available corrective spectacles used by workers do not provide effective eye protection against mechanical hazards in the workplace. One of the risks commonly occurring during work is hitting the head on some protruding elements, such as components of machines, buildings or tree branches in a forest. Because of the considerable weight of the human head and the speed of movement during impact, this type of accident may be very serious. This article presents a method of testing the mechanical strength of corrective lenses, simulating the results of an impact of the head on elements of workplaces. The results of tests of commercially available materials used for the construction of corrective and protective spectacles are also presented and discussed.

Corrosion of connectors used in equipment protecting against falls from a height.

Connectors are commonly found in personal equipment protecting against falls from a height. They are typically used outdoors and exposed to atmospheric factors, which can result in corrosion. This article presents the results of a study involving exposure of connectors to experimental corrosive media - neutral salt spray (NSS), acid salt spray (ASS), and seawater mist (for elements made of carbon steel and non-ferrous metals) - and to experimental conditions simulating the processes of pitting, stress, and intercrystalline corrosion (for equipment made of s`tainless steel). The results indicate that the main effects of corrosion on connectors include impaired operation and reduced strength of their mobile elements. The article presents methods of testing connector operation developed for this purpose. Corrosive damage to connectors has been presented in relation to potential hazards for their users.

The effect of the use of full body harnesses on their protective properties.

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.

Corrosion of retractable type fall arresters.

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.