Safety and effectiveness of gaseous ozone for residue-free textile decontamination in hospitals

Background

Healthcare-associated infections (HAIs) significantly impact patient safety and costs. Textiles for medical uniforms are known transmission vehicles, yet conventional laundering often fails to disinfect areas like seams or requires damaging chemicals and high temperatures. This study evaluates gaseous ozone as a sustainable, residue-free alternative for textile decontamination.

Methods

Antimicrobial efficacy was tested using a 900 rotary automatic dispenser (Zucchetti Centro Sistemi, Italy). This device features a fully hermetic design for an airtight environment and a catalyst system to accelerate ozone conversion back into oxygen, ensuring safe post-treatment conditions. The system includes an advanced sanitization system with two exposure programs (25 and 45 minutes) at a concentration of 4.5 ppm. Tests were conducted on 100% cotton, 100% polyester, and 40/60 blend fabrics artificially contaminated with Staphylococcus aureus, Escherichia coli, and Candida albicans (10-10⁵ CFU/mL). Ozone penetration was assessed using five stacked fabric layers. Worker safety was monitored via IQ-610 probes to calculate 8-hour Time-Weighted Average (TWA) values. Differences between ozone-treated and control samples were analyzed using Student’s t-test (p < 0.05).

Results

A 25-minute cycle significantly reduced the microbial load on all fabrics. The 45-minute cycle achieved almost complete pathogen elimination (>4-log reduction). Ozone effectively penetrated multiple layers, achieving total bacterial eradication and a 1.4-log reduction in C. albicans. Ventilation-only controls confirmed that reduction was solely due to ozone. TWA ozone concentrations remained below the 0.1 ppm OSHA limit at both 1 m and 50 cm distances.

Conclusions

Gaseous ozone via a rotary dispenser provides thorough decontamination, reaching areas resistant to conventional cleaning. This technology offers a safe, eco-friendly solution to reduce HAI transmission in healthcare settings.

Key messages

• Gaseous ozone provides high-level decontamination across multiple fabric layers, effectively eliminating key pathogens to reduce healthcare-associated infection risks through medical textiles.

• This sustainable, chemical-free method achieves near-total pathogen elimination across various textiles, offering a robust and eco-friendly alternative to improve hospital hygiene standards.