Evaluation of properties of elastomeric head straps of filtering facepiece respirators

Abstract

Frequent donning and doffing of filtering facepiece respirators (FFRs) can reduce their effectiveness due to the residual deformation of their elastic head straps. This study investigates the loss of elasticity of head straps during repeated use. Five elastomeric tapes were tested as FFR head straps, and their tensile strength was measured using a DU-100 dynamometer after repeated donning and doffing cycles. After eight consecutive uses, the protection factor drops significantly, requiring strap length adjustments to guarantee the specified level of user protection. The maximum tensile force of the elastomeric head straps causes residual elongation, which remains consistent after eight cycles. The study also establishes how strap elongation depends on the force and number of donning and doffing cycles. This knowledge is vital for designing better FFRs. Additionally, the research explores alternative materials for FFR construction to address strap elongation and its effects on performance and comfort.

Keywords:

• respiratory protective equipment
• filtering facepiece respirator
• head straps
• elastomeric tapes
• elasticity

Acknowledgements

This article is partially published and based on the results of a research task carried out within the scope of the fifth stage of the National Programme ‘Improvement of Safety and Working Conditions’ supported by the resources of the National Centre for Research and Development task no. III.PB.14 entitled ‘Development of Self-fitting Seal for Respiratory Protective Devices’. The Central Institute for Labour Protection – National Research Institute is the Programme’s main coordinator.

All test subjects gave informed consent for inclusion before participating in the study. Tests were performed on the study group taking part in the routine assessment of respiratory protective devices according to the European standards.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This paper is published and based on the results of a research task carried out within the scope of the fifth stage of the National Programme ‘Improvement of safety and working conditions’ supported by the resources of the National Centre for Research and Development, task no. III.PB.14 entitled ‘Development of self-fitting seal for respiratory protective devices’. The Central Institute for Labour Protection – National Research Institute is the Programme’s main co-ordinator.