Improved personal protective clothing for mining, oil and gas personnel working in hot environmental conditions
Creators: name: WATSON, Christopher
Publisher: name: RMIT University
Year: 2024
Subjects: classificationCode: 401001
subject: Engineering design
classificationCode: 401413
subject: Textile technology
classificationCode: 401605
subject: Functional materials

description: Personnel protective clothing (PPC) plays a critical role in safeguarding the health and wellbeing of industrial workers from workplace hazards and frequently covers more than 90% of the body. Engineering of PPC primarily focuses on mandatory protection compliance from hazards, such as flame, fire and electrical arc, with thermal attributes considered as a secondary factor. However, it is well known that wearing PPC imposes significant thermophysiological strains and high levels of discomfort on wearers, resulting in cognitive impairment, fatigue, reduced manual performance and heightened risk of injury, as well as restricting freedom of movement due to the additional bulk, thickness and mass required for protection.

There have been many studies of high-risk PPC, such as for firefighting and armed services, but there is little research into low-level risk categories, such as PPC commonly used in the mining, oil, gas, utilities and building and construction sectors, which employ a substantial number of workers across the globe, including an increasing proportion of women. It is common practice that PPC purchased in these industries is bought `off the shelf¿, and not specifically engineered for the environmental conditions in which they are worn. Further, many workers are exposed to hot and humid outdoor conditions for extended periods. In the next decades, guarding the safety and wellbeing of these workers will be made increasingly difficult by climate change, and therefore greater focus is needed to meet these challenges.

The aim of this study was to produce new knowledge about PPC performance and provide material and garment designers and engineers with a framework for development of PPC that provides improved thermal attributes and ergonomics for male and female workers exposed to hot environmental conditions. Objective methods were employed for evaluation of the performance of current PPC and evidence-based assessment of the improved performance of newly designed and constructed prototype PPC.  

As part of the first stage of the research, the literature on PPC and heat stress was systematically reviewed, focusing on literature relating to working conditions of high temperature and humidity. This review established the state of knowledge about thermal comfort challenges and key problems of PPC to determine knowledge gaps and the areas in which improvement could be made. The study then investigated and characterised materials currently used in low-level risk industrial PPC, which included physical parameters and attributes relevant to the thermophysiological comfort of the wearer, such as thermal resistance and liquid moisture management. Next, four current typical male and female PPC ensembles were tested on a sweating thermal manikin to determine their thermal attributes, such as thermal and vapour resistance. In addition, in order to determine differences in attributes between the PPC and civilian clothing, the research compared attributes of male and female civilian clothing and PPC. The findings of this stage revealed numerous opportunities to improve the PPC through engineering of novel materials and improved garment construction to support better thermal attributes, fit, utility and ergonomic performance for both male and female workers. 

In the next stage of the research, six new materials were engineered, of which four were used in development and engineering of final prototypes of the new PPC. These materials had significantly lower mass, thickness and density than the existing materials, as well as improved elastic attributes in some instances. The attributes of the new materials relevant to the thermophysiological comfort of the wearer were also substantially improved. The new PPC ensembles tested on the thermal sweating manikin demonstrated thermal attributes significantly better than those of the existing ensembles. The new ensembles provided enhanced utility, freedom of movement and improved fit, particularly the female ensembles. In excess of 30 changes were made to each of the male and female PPC ensembles to deliver improved garment shape, static and dynamic fit ease, utility and security of storage, through changes to construction elements and methods and new accessories. These improvements substantially narrowed the performance gaps between the new PPC and civilian clothing.

The outcomes of this research demonstrate that substantial improvement in the performance of PPC ensembles used in hot environments is possible, and that re-engineering of materials and garments can significantly improve the attributes relevant to the thermophysiological comfort of male and female PPC wearers. This research fills gaps in knowledge about industrial PPC performance, and provides industry with new scientific evidence about garment attributes relevant to thermophysiological function. Application of the outcomes of this research will have significant real-world impact for the tens of millions of workers worldwide who wear low risk category PPC, through improving their performance, productivity and safety in hot and humid conditions.