Introduction of Ergonomics and Comfort in the Selection of Personal Protective Equipment (ppe); Concepts for a New Approach

This paper describes an initiative to integrate aspects of ergonomics and comfort into a selection system for personal protective equipment (PPE). Selection criteria intended for PPE mainly focus on the efficiency of chemical protection to reduce respiratory and skin exposure. However, the efficiency of PPE is not exclusively determined by the protection aspects of respiratory protective equipment (RPE) or skin protection equipment (SPE), but it is also dependent on the suitability of devices for actual work situations. Aspects associated with the individual worker (e.g. anthropometrics), the task (e.g. work load) and the work environment (e.g. temperature and humidity) are often neglected and do not form an integrated part of a selection system. This paper provides a generic concept for a RPE and SPE selection system that intends to translate the conditions of use to objective evaluation points, and subsequently link these with the features of the PPE. By categorising and scoring different ergonomic and comfort aspects associated with the wearing of PPE, the system systematically incorporates the conditions of use into a risk-driven selection process. Based on a literature review, seven), respectively three main groups of ergonomicand comfort factors were identified for RPE (respirators) and SPE (gloves). Semi-quantitative or subjective evaluations of the work situation were used to assign values to the “task relevance” factors, whilst “PPE performance” aspects were derived from literature or manufacturers. By means of a simple scoring system an overall evaluation could be made, where PPE can be prioritised by distinguishing between ‘less suitable’ types or brands (negative end-score) and ‘suitable’ types (zero end score). This conceptual model needs to be developed further in order to construct a selection tool. Further developments include the refinement of the task analysis and an upgrade of the PPE performance data for the factors identified. Introduction It is generally assumed that the ‘overall’ effectiveness of personal protective equipment (PPE) is determined by the ability of the PPE to retain workplace contamination, i.e. the ‘technical’ protection provided, as well as the conditions of use in the workplace, i.e. the human factor. During Technical Meetings of the European Chemicals Bureau (ECB) two key issues related to PPE and exposure to chemical were identified, i.e. proper functioning and proper use (Doc. ECB4/32/98). Proper functioning implies that PPE should be designed and tested to ensure reproducible and quantifiable reduction of exposure. Chemical protection in workplace conditions is determined by an assessment of the toxicological properties of a substance or product (hazard), the exposure level of the chemical and the protection factor of a PPE device or brand. Protection factors are assigned for various RPE designs based on field studies that have been conducted to assess workplace protection factors (WPF), as reflected in US and UK standards (ANSI, Z,88.2,1992; BSI, BS 4275, 1997). For SPE no such protection factors have been assigned, hence the effectiveness of chemical protective equipment is derived from laboratory test data on chemically integrity, e.g. degradation, or data on permeation or penetration. In addition, proper use criteria are vital to ensure that PPE is both suitable and fitting for a given work task. Moreover, wearers should be instructed and trained in the proper use and maintenance of PPE. In the past, the emphasis was often placed on the ‘efficacy’ during PPE selection, and little attention has been given to the ergonomic and comfort aspects associated with the wearing of PPE. Until now, a systematic approach to incorporate ergonomic and comfort aspects into a selection system is lacking. This paper describes an initiative to develop such an approach, and to optimise the protection of individual workers during performance of their individual tasks. Methodology The selection system presented here incorporates the current decision logic used for the selection of adequate types of RPE and SPE. First, ergonomic and comfort factors are selected that are relevant for performing tasks and that are known to be affected by the use of PPE. Our basic assumption is that the use of PPE limits a worker’s task performance and comfort compared to a zero-situation, i.e. a non-PPE use scenario. Therefore, we only consider PPE types that are the least uncomfortable and the most compatible with a specific task. The following criteria are considered relevant for the actual selection of the most appropriate PPE. task: what tasks must be performed by the worker, and what are the requirements in terms of vision, mobility and reach, dexterity, communication etc. work environment: under what environmental conditions must the task be performed. worker: this category includes workers dimensions, and personal aspects such as use of glasses, allergies etc. The selection strategy applies the criteria given above to systematically select PPE in two consecutive steps: (1) ergo-comfort selection to determine the suitability of a type of PPE for a given work situation and 2) personal fitting selection to establish how fitting the PPE is (or tailored to the wearer in question; this may involve a field-test and try-out in practice). All reported ergo-comfort factors obtained from literature studies were categorised and clustered in main categories (Goede et al., 2001, Brouwer et al., 2002). For the RPE selection system seven major categories could be distinguished, whereas for the SPE system three categories were identified (tables 1 and 2, respectively). Table 1 Principal categories of ergo-comfort factors for respirators Main category Example of factors Vision Visual field Visual acuity Communication Audibility of users’ speech Users’ hearing Respiration In/ exhalation CO2-retention Physical task performance Mobility Body posture Dexterity/ stability/ precision Environment Heat stress/ Cold