A global study of the performance of cleanroom garments over their life cycle

Article by Matheus Barbosa, Jean-François Teneul

Sterile garments for cleanroom use often present a variable performance over their entire life cycle as they are vulnerable to damage from laundering and sterilization methods. A study was conducted to understand how reusable garments perform when subjected to multiple laundering and irradiation cycles – tear strength, particle shedding, permeability, etc. The study enables a cost comparison with single-use garments.

In the context of a global business with ever-increasing quality standards and effectiveness requirements as well as the latest draft review of the Good Manufacturing Practice (GMP) Annex 1 of December 2017, one of the main technical areas explored is related to studying and mitigating potential process/product contamination risks against biological bodies, particulates and pyrogen agents. One key strategy for cleanroom supervisors should be to carry out complete Risk Assessments in order to map, classify, and then reduce contamination risks.

Humans are the main source of potential contamination inside cleanrooms
(more than 70%), as shown by several past global studies (Akers, J. et al., 2004; Ramstorp M, 2000 and Whyte and Hejab, 2007). Hence, cleanroom garments serve as the last protection barrier against controlled environment contamination by the thousands of human particles (potentially carrying microorganisms) that are shed every minute. In terms of contamination risk management, it is critical to evaluate the variables related to human contamination and cleanroom garment barrier performance besides HEPA filtering, process air flow velocity and other factors. This study aims to explore several important technical aspects of cleanroom garments that should be considered when evaluating contamination risks.

The process of wearing, laundering and sterilizing reusable cleanroom  garments can impact their physical properties and change their functionality.
Laundering and wearing abrades garment fibres. Simultaneously, changes to the polymers that make up the garments can occur at the molecular level. Although routine visual inspection is often part of garment quality evaluation programmes, non-visible properties also change with time.

When selecting reusable garments for use in cleanroom environments,
it is important to understand how they will perform over their intended life
cycle. Consideration of all the degradation aspects should be part of the decision process for when to take reusable garments out of service, or alternatively to change to a single-use garment system. Several factors should also be considered when evaluating intrinsic risks generated by cleanroom garments, such as: particle shedding, biological/ particle barrier, worker comfort and protection, durability, packaging, sterilization continuous validation –
besides process and supply factors: logistics chain reliability, damages and
repairs, shrinking and ergonomic fit, among others.

This is an extract of an article from CACR Issue 38. To read more of this article and others like this subscribe to the quarterly CACR