Grantee Research Project Results
Final Report: Decontamination of Category A Viruses on Porous Surfaces and Sensitive Equipment
EPA Contract Number: 68HERC20C0005Title: Decontamination of Category A Viruses on Porous Surfaces and Sensitive Equipment
Investigators: Lorch, Daniel
Small Business: METSS Corporation
EPA Contact: Richards, April
Phase: II
Project Period: November 1, 2019 through October 31, 2021 (Extended to October 31, 2022)
RFA: Small Business Innovation Research (SBIR) - Phase II (2019) Recipients Lists
Research Category: SBIR - Homeland Security , Small Business Innovation Research (SBIR)
Description:
METSS was funded by the SBIR program to develop a safe, robust, rapid, and effective chlorine dioxide (ClO2) gas dispersion system to be used for on-site decontamination of unoccupied hospital and non-hospital spaces. The technology was designed to meet the demands of the healthcare market to decontaminate porous and nonporous materials, including sensitive equipment, in rooms or vehicles used for patient care or transport. This need was evident during the care and treatment of Ebola patients in the United States in 2014. At that time, many facilities did not have the means to properly disinfect large items (e.g., furniture on-site; therefore, these items required transport off-site for proper treatment and disposal - a process that has inherent safety risks and associated cost. The ability to decontaminate a room containing porous materials and sensitive equipment on-site in a non-destructive manner would be an attractive product to the health care industry and meet a critical need for low-cost, simple solutions to decontaminate non-medical spaces as well. This project was completed in three phases starting with a Phase I feasibility study, followed by a Phase II technology development project, and concluding with a Phase II Commercialization Option for further technology development and commercialization planning.
Summary/Accomplishments (Outputs/Outcomes):
In the Phase I project, METSS demonstrated the feasibility of a novel ClO2 gas dispersion system to achieve >4-log inactivation of an Ebola surrogate in a full-scale, mock bedroom using a low-tech, non-automated, proof-of-concept prototype. In the Phase II project, technology was developed further to meet the anticipated needs of end users. Through full-scale laboratory testing, METSS was able to develop a novel rapid ClO2 gas generation and dispersion process. This process was vetted through multiple iterations of testing to optimize the operating parameters. Simultaneously, time-to-kill efficacy tests were performed with Phi6 bacteriophage (a surrogate to Ebola virus and other enveloped virus), MS2 bacteriophage, and several bacterial pathogens including Staphylococcus aureus and Pseudomonas aeruginosa. The D-values (the time required to achieve a 1 log reduction (LR) (i.e., 90% at a given disinfection treatment) were established for the organisms on porous (fabric, carpet, bare wood) and non-porous substrates (glass). Efficacy testing was performed in a room-sized test chamber (a 1169 ft3 retrofitted ISO shipping container) where the temperature was generally in the range of 18 to 23°C and the relative humidity was controlled at 65 to 75%. The results identified the approximate gas treatment (accumulative gas concentration; expressed as ppmvh [parts per million · unit volume · hour]) that would achieve >4LR and >6LR of Ebola and non-spore-forming bacterial pathogens, respectively.
Once the gas generation/dispersion method was developed and time-to-kill efficacy tests were completed, a breadboard system was constructed. The system included all components to perform a full disinfection cycle: pre-conditioning the room with humidity, disinfecting the room with gas, and degassing (or neutralizing) the room until the concentration returned to 0 ppm (safe to enter). After refining the breadboard system, a 1st-generation functional, automated prototype (GEN-1) was constructed to a set of specifications that were based, in-part, on end-user feedback. The Phase II project concluded with a full-scale ClO2 room fumigation demonstration in which duplicate trials were performed to assess the functionality of GEN- 1 and its ability to fumigate an enclosed space similar in size to a hospital room. The demonstration was a success; a gas treatment of approximately 300 ppmvh at 23 °C and 65% RH was effective at achieving >4 LR of an Ebola surrogate and several non-spore-forming pathogens on materials including on glass, aluminum, carpet, and fabric. Disinfection on wood was also good; however, a low number of virus and bacteria were recovered from this porous substrate post-treatment resulting in log reductions of 3-4 logs. The GEN-1 hardware was shown to be fully functional. The process was also shown to be non-destructive to sensitive equipment such a laptop and external disk drive as well as other electrical devices including a household humidifier and dehumidifier, and the prototype itself.
METSS continued to advance the development of a laboratory prototype in the Phase II Commercialization Option project during which METSS formed a commercial alliance and intellectual property agreement with ChorusTM, LLC (Boston, MA). Chorus is primarily focused on developing process-controlled devices to generate ClO2 for disinfection applications in medical, transportation, and facility-based applications. Chorus assembled a team of product development and design engineers, software and firmware developers, manufacturing specialists, marketing experts, go-to-market strategists, regulatory experts, and executives with demonstrated capabilities in the medical device market. METSS leveraged the engineering product design activities performed concurrently by Chorus to improve device performance and functionality of the room fumigation technology. Collaboration with Chorus helped align the product and commercial development activities and streamline the technology transition, manufacturing, and commercialization process; and develop a regulatory strategy for the device, which was influenced by third-party discussions in targeted commercial applications.
During the Phase II Option project, METSS evaluated ClO2 generation methods and chemistries, ClO2 detection technologies, and ClO2 remediation methods to optimize unit operations and performance, including the incorporation of process control methods. Gas generation/dispersion methods were evaluated and showed excellent potential for use; however, the most vetted method under this project, using a combination of sodium chlorite and sodium persulfate, remained the method of choice. The project concluded with a build of a 2nd generation prototype (GEN-2; Figure 1) that was more rugged and portable than its predecessor. The operability of the GEN-2 was assessed in a mock field demonstration in a room-setting against an Ebola surrogate and two pathogenic non-spore-forming bacteria. In a demonstration with a treatment of 680 ppmvh (or 100-150 ppmv for 6 hours), the GEN-2 unit achieved > 4 log reduction (LR) of Phi6 bacteriophage (Ebola surrogate) on non-porous and porous materials; and >3 LR and >5 LR of Staphylococcus aureus on non-porous (aluminum) and porous (fabric) materials, respectively. The treatment did not adversely affect the functionality nor change the appearance (no discoloration or cracking) of electronic equipment including a laptop and external disk drive, household humidifier and dehumidifier, and the prototype. The demonstration illustrated the devices' capacity to conduct rapid on-site room decontamination, rendering room contents safe for further handling. METSS will pursue Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA)) registration [antimicrobial air treatment, air sanitizer], under EPA's antimicrobials division (AD) as an antimicrobial active ingredient (sodium chlorite/chlorine dioxide).
Figure 1. GEN-2 prototype for room disinfection using ClO2 gas.
Conclusions:
The proven concept of ClO2 fumigation for unoccupied room decontamination was further refined through the development of an on-demand method of ClO2 gas generation and accelerated gas dispersion that can be controlled and automated in a compact, remotely operated device. METSS successfully transitioned from using off-the-shelf ClO2-generating sachet technology (designed to slowly generate large volumes (liters) of dilute aqueous solutions of ClO2 gas) that was not easily scaled nor adaptable for use in an automated device in the initial Phase I project to developing novel methods of fast, controlled ClO2 generation with minimal volumes in Phase II and this Phase II Option. The first prototype (GEN-1) was used to further assess functionality and efficacy of the device providing additional insight of the gas treatment required to meet the objectives of achieving 4-LR and 6-LR of virus and bacteria, respectively, with future aspirations of acquiring EPA registration of the technology with viral and broad spectrum and/or hospital disinfection claims.
The nature of the device and gas generation technology enables the unit to respond to variables such as room size, maximum concentration, target treatment, and cycle time for optimum adaptability to differing environments and cycle requirements. The GEN-2 unit, with minimal control scheme, was sufficient to hit target cycle parameters and effectively communicate and control critical device components; although, the controller is capable of much more discrete functions intended for implementation in future development efforts. The device has the capability to generate a wide range of gas concentrations to allow flexibility for the end-user to select the desired treatment that best fits their operational needs, whether for sanitization or disinfection of porous and non-porous materials without destroying sensitive equipment or reducing the risk of infection caused by aerosolized virus particles, such as SARS-CoV-2.
METSS will need additional funding to refine the technology and bridge the gap between development and commercialization. METSS' end goal will be to register the technology with the FIFRA as a room fumigation technology and bring it to market. The registration will be key in gaining acceptance from end-users as a commercial product. The ultimate goal is to market the technology as a room disinfection device having "hospital and broad spectrum" and "virucide" disinfection claims. METSS is working with a commercial partner to support these efforts.
The utility of this ClO2 room fumigation technology can be universally applied to a number of non-medical markets including education, transportation, hospitality, agriculture, food and beverage, and pest control; however, the healthcare market has the greatest and most immediate need for such a technology. The most significant utility would be for routine and non-routine unoccupied-space disinfection or sanitization in healthcare facilities or EMS units to reduce risk of transmission of viral and bacterial pathogens from fomite contamination, including a Category A level threat.
A third-party market assessment provided very favorable findings for healthcare market applications and identified numerous parties interested in the technology, as well as potential commercial partners. During the Phase II project, Foresight Science & Technology solicited end-users from hospital and non-hospital settings (nursing home, clinics, hospice) to identify the specific attributes (i.e., features and capabilities) the device must possess for them to consider using the technology. Experts/end-users indicated that new decontamination device must be user friendly, durable, portable, and Wi-Fi or Bluetooth enabled with cybersecurity protection and artificial intelligence/robotic integration into each unit. Foresight ascertained that the healthcare market is the most important market for commercializing this technology and is more likely to command a higher price than markets that would utilize units to remediate homes, nursing homes, or warehouses. Forensics and crime scene disinfection could be another important market for this technology and obtaining a good G-Star evaluation and rating could improve the commercialization potential of this technology.
An on-site (defined herein as the location at which the waste is generated; not a biohazard waste treatment facility) room disinfection process would significantly reduce the need to transport contaminated waste to an off-site treatment facility. The technology could also be used for routine and non-routine room treatment to inactivate bacterial, fungal, or viral pathogens. To expand the usefulness of the technology, the process should be efficacious against a range of pathogens and facilitate rapid disinfection of potentially infectious materials in hospitals and other healthcare facilities such as outpatient clinics, nursing homes, ambulatory services, field deployed medical treatment centers (utilized by military operations and agencies such as the World Health Organization) and non-healthcare settings like residential homes, hospitality establishments, and businesses.
The target end-users could be anyone in need of decontaminating a room (i.e., space) and the items within. The technology will be sold as a fumigation device with a distinct volume-dispersion advantage over commercially available disinfection solutions such as bleach, quaternary ammonium salts, and alcohols that are geared for non-porous materials and surfaces (glass, stainless steel, vinyl, etc.). In comparison to other fumigation technologies, the proposed ClO2 generation method is easy to transport, relatively inexpensive, and requires no special training to operate. While the initial targets were Category A viruses, which are rarely seen in the US, the technology is applicable to numerous pathogens and applies to numerous markets such as healthcare, food safety, sports/fitness, and military sustainment.
SBIR Phase I:
Decontamination of Category A Viruses on Porous Surfaces and Sensitive Equipment | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.