Cleaning and sanitation of modular carpet tiles: protocol development and health considerations

We previously reported (RAMC 2014) a developing protocol for a bi-component hydrogen peroxide-quaternary product that provided >4 log reduction vs scrubbed nylon carpet controls of recoverable bacterial species specified in ASTM 2966, Standard Test Method for Quantitative Assessment of Sanitizing Solutions for Carpet. A 3-log reduction was observed for Aspergillus brasilensis. Herein we present light microscopic and scanning electron microscopic data demonstrating the effect of the cleaning and sanitizing regimen. An Appearance Retention Tester (ART Machine) was used for accelerated soiling and wear of new carpet tiles. A total of 20 grams of soil per 1/4 tile (80g/m²)  was applied to mimic a two year soiling with no vacuuming or extraction maintenance. Carpet tiles with controlled soiling (under ambient conditions) and naturally soiled carpet tiles (N=9) from an acute care hospital, a high traffic airport, a seafood restaurant and corporate, education, and retail facilities were examined pre- and post-sanitizing with stero-light and scanning electron microscopy. All naturally soiled samples examined had evidence of soiling equivalent to or exceeding soiling levels on the tiles with ART Machine processing. The cleaning and sanitizing regimen in development markedly restored aesthetic qualities of all soiled carpet tiles. Particulates, including microbes, were nearly imperceptible among carpet fibers following processing of samples with accelerated soiling. Fiber luster and organic odor reduction were noted particularly for the naturally soiled samples. Regimens which clean, deodorize and sanitize, modular nylon carpet tile may effectively reduce or empty “indoor environmental sinks” as well as improve overall indoor air and environmental quality.