Potential Penetration of Engineered Nanoparticles under Practical Use of Protective Clothing Fabrics

Abstract

The commercial application of engineered nanoparticles (ENPs) has rapidly increased as their unique properties are useful to improve many products. ENPs, however, can pose a major health risk to workers through exposure routes such as inhalation and dermal contact. Research is lacking on the protective nature of lab coats when challenged with ENPs. This study investigated multiwalled carbon nanotubes (CNTs), carbon black (CB), and nano aluminum oxide (Al₂O₃) penetration through four types of lab coat fabrics (cotton, polypropylene, polyester cotton, and Tyvek). Penetration efficiency was determined with direct reading instruments. The front and back of contaminated fabric swatches were further assessed with microscopy analysis to determine fabric structure with contaminated and penetrated particle morphology and level of fabric contamination. Fabric thickness, porosity, structure, surface chemistry, and ENP characteristics such as shape, morphology, and hydrophobicity were assessed to determine the mechanisms behind particle capture on the four common fabrics. CNTs penetrated all fabrics significantly less than the other ENPs. CNT average penetration across all fabrics was 1.83% compared to 15.74 and 11.65% for CB and Al₂O₃, respectively. This can be attributed to their fiber shape and larger agglomerates than those of other ENPs. Tyvek fabric was found to be the most protective against CB and Al₂O₃ penetration, with an average penetration of 0.06 and 0.11%, respectively, while polypropylene was the least protective with an average penetration of 40.36 and 15.77%, respectively. Tyvek was the most nonporous fabric with a porosity of 0.50, as well as the most hydrophobic fabric, explaining the low penetration across all three ENPs. Polypropylene is the most porous fabric with a porosity of 0.77, making it the least protective against ENPs. We conclude that porosity, fabric structure, and thickness are more important fabric characteristics to consider when discussing particle penetration through protective clothing fabrics than surface chemistry.