Grantee Research Project Results
Final Report: Encapsulation of Biological Contaminants in Transportation Systems
EPA Contract Number: EPD18005Title: Encapsulation of Biological Contaminants in Transportation Systems
Investigators: Beltis, Kevin J
Small Business: TIAX, L.L.C.
EPA Contact: Richards, April
Phase: II
Project Period: February 1, 2018 through January 31, 2021
Project Amount: $299,938
RFA: Small Business Innovation Research (SBIR) - Phase II (2017) Recipients Lists
Research Category: SBIR - Homeland Security , Small Business Innovation Research (SBIR)
Description:
The US EPA has responsibility for protecting the US population and the environment from potential exposure to chemical, biological, and radiological (CBR) hazardous materials. It has become a grim reality in this post-911 era that "Preparedness" is a key requirement for first responders. The EPA's Homeland Security Research Program (HSRP) is tasked, in part, with "remediating contamination incidents and natural disasters." Systems such as railway and subway cars present a particularly unusual scenario due to their complexity of construction and, as a result of their mobility, for the unpredictable potential to affect nearby resources. The unique issues associated with providing a response to a release on a transport system such as a railcar or subway car are numerous. Given a contamination event does not occur at a fixed site, remediation efforts must be rapid, be highly portable and quickly provide a measure of sealing the hazard from creating secondary contamination. Liquid wash-down systems have the effect of creating run-off that will contaminate the surrounding terrain that, in the case of the nation's rail and public transportations, could be in a remote or heavily populated location, each with its own set of response issues. The added complication of a train supported by wheels on a rail track prevents installation of ground containment. Mindful of these concerns, the EPA identified the need to specifically mitigate (i.e., inactivate or remove) the release of a biohazard on a railcar system.
This TIAX LLC ("TIAX") effort to develop a strippable fungicidal coating addresses this specific need. The method provided here, using a strippable film, was originally developed by TIAX under a SBIR Phase I contract in the 2003 - 2005 timeframe to mitigate aircraft contamination from chemical/biological attack, was shown to be very effective. In 2006, TIAX adapted its use for building biohazard remediation for the EPA. The TIAX method uses a liquid spray-applied coating to encapsulate both liquid chemical and particulate hazards. Upon curing, the contaminant is contained within the film and readily removed for disposal. Under the SBIR Phase I, II and commercialization efforts of the subject Contract EP-D-18-005 for the EPA's Office of Homeland Security, TIAX validated the capability of the strippable film as an excellent means for surface hazard mitigation from a biological agent release on a subway car.
The principal goal of this effort was for validation of a formulated product including an active biocide. In the development we focused on the quaternary ammonium/phosphonium compounds (QAC/QPC) as principal candidates for the biocide. We used a design of experiment to evaluate mixtures of the aqueous-based polymers to determine usable systems as biocides and also identified a commercially available portable, battery-powered sprayer for the coating applications. The inoculants in this project were chosen based the threat scenario and identifying reasonable surrogates. Given Bacillus anthracis as the threat of most consequence, used both Bacillus thuringiensis and Bacillus atrophaeus as surrogates, to ensure a capability for cross-referencing of data.
The decontamination technique developed by TIAX can mitigate exposure to the contaminant by immediate encapsulation, prevent cross-contamination and minimize the quantity of hazardous waste generated. Our assumed scenario was for the release of a powder-dry biological threat onto a railcar or subway car with contaminant settled on the various surfaces. Incorporating an active biocide into the coating provides immediate and, once dried, permanent encapsulation of the biohazard with constant and direct contact of the biocide. The removal process uses the technique of rolling the contaminant inward as it is stripped from the surface. As a result, the contaminant is permanently sequestered within the rolled material, ready for disposal without special handling. The technique has the following benefits:
· 97% removal efficacy of an aerosolized, powdered agent simulant.
· 98 - 71% removal efficacy of a liquid-suspension biological inoculant (Bacillus atrophaeus -Bg -and Bacillus thuringiensis - Bt); dependent upon surface type; (e.g., reaction of suspension inoculant with steel and other materials that are not representative of an aerosolized dispersion).
· Formulation of a flexible, strippable coating using a safe and effective fungicide. Formulation provides a 5-log biohazard reduction (removal + kill) capability.
· No need for establishing secondary containment ahead of treatment (i.e., no enclosure needed around contaminated equipment - railcar or other transportation unit: bus, plane, or boat - and given there is no water washdown, there is no need to install ground containment devices onto rails).
· Reduce risk to the hazmat responders, the public and the environment by immediate encapsulation of the hazard. The treatment materials are non-toxic, and environmentally safe.
· Technique does not require significant outside logistical support (no need for: electrical support, external water supply, etc.) and no special tools needed for removal.
· Minimum manpower: one or two technicians for coating application and subsequent removal.
· Application using a commercially available, hand-held (battery operated) paint sprayer system.
· Use on full-scale subway car under temperate environmental conditions to ensure efficacy on systems of interest.
· Material costs for typical railcar interior surface encapsulation (ca. 2100 square feet) less than $10K
· Treated materials of construction are not adversely affected (e.g., does not degrade or corrode)
· The amount of solid waste generated is approximately 15-25 kg with no liquid wastes.
· Encapsulation allows time for subsequent, more complete action planning (e.g., either complete treatment in place or move the hazard to a better location for all concerned).
Additional Phase II goals were to: demonstrate use in commercially available sprayer systems; and perform product demonstration on a railway/subway car (in whole or part) with a collaborating mass transit system or training center. TIAX worked with the Massachusetts Bay Transit Authority (MBTA) to make use of some real-world assets and prepared test coupons made of representative materials of construction for subway cars. The items identified were prioritized to include the more prevalent and the more difficult surfaces to treat and included Formica®-type wall and ceiling panel, stainless-steel handrails, vinyl covered seats and non-skid floor covering.
Summary/Accomplishments (Outputs/Outcomes):
In determining efficacy on Formica® panels salvaged from one of the mass transit trains, we deposited 1-mg onto a 25-cm2 area corresponding to a 8x107 CFU/m2 inoculant. We evaluated formulation biocide concentrations from 1% to 2% then 3% yielding approximate dried film biocide concentrations of 2%, 4% and 6% respectively. The results for the 1% formulation indicated a 1-log reduction (i.e., decontamination efficacy: removal plus inhibition/kill). The 2% formulation (initial concentration) showed a much improved 2-3 log reduction. The 3% starting biocide concentration had a significant affect in having the strippable decontamination method shows 99.999+% or a 5-log reduction. One of the 3% concentration samples showed zero cultivability (i.e., complete removal/kill). The log-reduction for handrails was shown to be on the order of 1.8 - 3, a reasonable finding considering the literature shows that stainless-steel is notorious for harboring microbial contamination.
As a sample of opportunity, we were given a flooring panel with mold infestation to demonstrate the utility of the biological decontamination technology on a qualitative basis. Of interest was the panel's rubberized polyurethane-based system containing grit non-skid coating application. Following treatment with our strippable coating, the surface was clean of the mold as shown in the figure below demonstrating no wear from the process. In addition, we observed no regrowth was after several days.
Figure 1. Mold infested textured surface treated with TIAX Strippable Bio Decon (before, application, and after)
Following the Phase I and II SBIR effort, the commercialization option allowed demonstration of storage stability. During these evaluations, we determined that the formulation with the initial 3% biocide had a short duration shelf-life, on the order of about two weeks. We found a direct relationship of useable storage life to biocide content. At 2.5% the formulation could be useable for about a month. At 2% its usability was between 2 and 3 months. At 1.5%, the usability is increased to least one year according to the accelerated storage study (i.e., 45°C, for 63 days actual time - equivalent to about 360 days at 20°C).
Cultivability evaluations at the end of the storage cycle were conducted using a Bt spore suspension as the inoculant onto tryptic soy agar plates. The negative control achieved repeatable cultivability. Samples treated by applying a coating of the TIAX strippable formulation produced no observed growth in any of the samples immediately after removing the coating. The plates were rechecked after being replaced in incubation for an additional 24 hours. Again, no growth was observed with formulated product aged for the equivalent of one year at standard conditions showing 100% removal and/or inhibition for any Bt spores that may have remained.
Other efforts conducted during the commercialization phase included:
· a marketing assessment, ultimately used to determine production options,
· preparing a GHS compliant Safety Data Sheet (SDS) for transport and other safety concerns
· continuing the patent application/review process, and
· understanding the EPA Pesticide/Fungicide registration process
Based upon a marketing assessment, TIAX made the decision that it will make use of in-house or toll manufacturing to ensure integrity of manufacturing (product quality); maintain oversight of packaging; selection of application equipment as well as marketing, sales, support, and training for the limited market currently anticipated. When necessary, TIAX will pursue toll manufacturing as greater interest develop beyond our capabilities.
As noted, the patent application process continued over the duration of the development effort with various authorities, the filing having been submitted in July 2018. TIAX has worked with its own team including in-house and outside counsel to work on ensuring the appropriate documentation and filings are completed and updated as required. Incorporation of a biocide into the formulation will eventually require registration application as a fungicide. As the patent process continues, TIAX will pursue the registration process, which will continue as a TIAX internally funded project.
TIAX has, therefore, successfully completed development and evaluation of a strippable, biocidal coating with demonstrated efficacy in removing and/or inhibiting the growth of Bt as a surrogate for the target sporulating bacilli (e.g., Bacillus anthracis). The accelerated aging storage evaluation has led to a one-year, shelf-stable formulation with a demonstrated utility on surfaces typically found in railway and subway transit cars.
Conclusions:
The next critical step for commercialization is to pursue EPA Fungicidal Registration. Given the base biocide used in this effort is a commonly used fungicide, we are confident that this effort may be fully carried forward to market. In brief, we envision the following utility:
· Use:
· Controlling microbiological contaminants that may become entrained in the air (e.g., anthrax)
· Treatment of hard, non-porous surfaces
· Differentiated advantages:
· Initial area containment unnecessary
· Immediately encapsulates hazard upon application, preventing cross-contamination
· Uses commercially available, portable (battery-operated) application system
· Smaller response team (requires only one 2-person team for treatment)
· No liquid run-off (i.e., no secondary contamination)
· Solid waste only (acute contact/inhalation hazard issues mitigated)
· Ingredients: Proprietary, generally recognized as safe
· Production: Packaging: Plastic open top, 1-Gallon Pail or 5-Gallon
· Buyers/Users: Homeland Security and civil authorities for transit systems (trains, planes, buses)
· Competitors: No known commercially available similar products
· Manufacturing: TIAX and/or toll manufacturers
· Sales/Distribution: TIAX licensing to civil/military and first responder specialty suppliers
SBIR Phase I:
Encapsulation of Biological Contaminants in Transportation Systems | 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.