Pop quiz: What’s the difference between cleaning, sanitizing and disinfecting a school bus? Not sure? You’re not alone. The confusion about what each means and how to safely accomplish them has school bus manufacturers and suppliers concerned about unforeseen and unintended consequences that could cost their customers dearly.
The stance of the major OEMs—Blue Bird, IC Bus and Thomas Built Buses—is that only soap and water is appropriate for school buses. They reiterated as much during a National Association for Pupil Transportation webinar last month. Seconding those perspectives are a number of equipment suppliers, among them seating, occupant restraint and wheelchair securement manufacturers.
Most of the guidance emanating from the federal and state levels regarding response to the novel coronavirus is limited. To fight the common flu in schools, a type of human coronavirus but one for which a vaccine exists, the Centers for Disease Control and Prevention (CDC) recommends washing surfaces and objects that are touched often with general household cleaners and following up with an EPA-approved disinfectant.
Meanwhile, bus OEM owner manuals address how to clean school buses but not how often. And OEMs warn against using disinfectants, though IC Bus says wipes containing a 70% solution of isopropyl alcohol can be used on seats (when not hot from the sun) and seatbelts.
It is important for student transporters to know the difference between cleaning, sanitizing and disinfecting. According to the CDC, cleaning refers to the physical removal of germs, dirt and impurities from surfaces or objects with soap and water. “This process does not necessarily kill germs, but by removing them it lowers their numbers and the risk of spreading infection,” the CDC states.
Meanwhile, sanitizing reduces the bacteria identified on the product’s label on surfaces and in laundry, according to guidance published by Clorox. Most everyday hand gels fall under the sanitizer category. A pump bottle of Purell, for example, claims that it kills (or at least reduces) more than 99.99 percent of germs.
Purell, Clorox and others also sell surface sprays for hard and soft surfaces that are approved by the U.S. Environmental Protection Agency (EPA) for use on the SARS-CoV-2 virus that causes COVID-19. Such sprays fall under the category of disinfectants.
Disinfecting destroys or irreversibly inactivates both the bacteria and viruses identified on the product’s label (like influenza and rhinovirus) on hard, nonporous surfaces. There are many types of surface disinfectants, however, some of which are inappropriate for a school bus environment. These can include hospital-grade germicidal bleaches and cleansers that are not commonly found outside of a healthcare environment, to limited- spectrum disinfectants such as toilet bowl cleaners.
Household bleach products are also not recommended to be used on school buses for a variety of reasons. When used alone, liquid bleach fumes (and those of other disinfectants) can cause lung irritation. They also can exacerbate conditions suffered by students with disabilities, warn student transportation experts. Combine bleach with vinegar (chlorine gas), ammonia (chloramine) and rubbing alcohol (chloroform), and the result is potentially deadly. Plus, according to guidance published by Toyota regarding vehicle cleaning, bleach can ruin plastics and paint because it must be diluted with water and thoroughly rinsed.
“You never want to use bleach on a school bus,” commented Denise Donaldson, the editor and publisher of SafeRideNews, dedicated to child passenger safety.
She also pointed out that student transporters should be careful about the cleaning or disinfecting products they use in general, as the ingredients can also trigger allergic reactions in students.
The products approved by the EPA to combat SARS- CoV-2 include non-bleach hospital disinfectants like Vital Oxide, the solution used by AeroClave’s vehicle decontamination systems. They range from portable sprayer hoses that disperse fog in cutaway buses, to a larger refrigerator-sized portable system for a 40- foot bus, to a hands-free wall or shelf mount. They all disperse chlorine dioxide (ClO2), which “seem[s] to offer the fast turn-around times of UV (ultraviolet) systems with the ability to ensure whole room decontamination utilizing a safe, EPA-approved disinfectant, coupled with ease-of-use,” according to product literature. It also meets Occupational Safety and Health Administration and National Fire Protection Association specifications.
Automotive International, the maker of vehicle rust protection ValuGard, also offers G-CLEAN, which consists of pre-mixed, water-based sanitizer and a disinfectant. Company President Richard Hallbert shared that EPA has approved the non-toxic, triclosan-free spray to be used on SAR-CoV-2, with the company claiming it can kill 99.9-percent of viruses on hard, non-porous surfaces. It dries and disinfects in about 10 minutes.
GOJO Industries, the maker of Purell, pointed out that its EPA-approved surface disinfectant products differ because they are alcohol-based. Purell disinfectant quickly evaporates, leaving no residue, and it is safe to be used around children, the company said. “It’s not a harsh chemical treatment that will deteriorate components,” added Morgan Paris, GOJO’s market development manager.
For example, she said that many collegiate athletic departments have switched to Purell products because they don’t damage weights, benches and flooring.
She commented that the company also offers a bodily fluid kit that includes personal protective equipment (gloves, googles, shoe covers), a sprayer to disinfect an area from a distance, including killing blood-borne pathogens, and hand sanitizer. “You then throw it away in a regular trash can. There is no need for biohazard bags,” Paris shared.
The company is also developing a battery-powered sprayer that she said could be used between routes on the school bus.
Another common disinfectant used at the home, office and on the school bus is made by a popular bleach manufacturer but doesn’t contain bleach. Clorox lists its wipes and five other products on its website as meeting EPA criteria for being used on SARS-CoV-2 as well as other human coronaviruses. The wipes label warns, however, that it should only be used on hard, non-porous surfaces. And if that surface comes into contact with food (or say a student’s face or mouth), “a water rinse is required.”
Another product that Clorox said meets the new coronavirus kill requirements is the company’s professional series Total 360 electrostatic sprayer. Used in classrooms and school buildings, it also has a school bus application. Cody Cox, the director of transportation and maintenance for Community ISD outside Dallas, has been using it for a couple of years. “We do not do anything besides spray the seats. It dries very fast,” he shared, adding that seats sprayed at his previous district resulted in no issues.
Cox’s experience doesn’t assuage the concerns of Donaldson at SafeRideNews. She said that she has been gathering evidence that shows the general guidance is- sued by the CDC and states fails to take into account the potential damage that different disinfectants can cause to school bus components.
“Chemical foggers … don’t discriminate between what needs to be crashworthy and what doesn’t,” she explained. “And webbing and buckles are certainly hot spots in terms of touch points, so they are being targeted for wipes and sprays, but they shouldn’t be cleaned using chemicals.”
Donaldson pointed out that the CDC has already stated that the new coronavirus will die off by itself after one week, so she advised that car seats and other equipment be removed from service for that long after one use, if possible. She suggested that student transporters should at least rotate car seats and safety vests, if there is enough inventory.
The entire issue has become a major discussion point for the Student Transportation Aligned for the Return
to School (STARTS) Task Force, as it prepares actionable best practices for school districts and bus companies to implement into their operations. A report with recommendations is expected this month.
Among suppliers concerned with the rise in use of disinfectants is IMMI, which manufactures the SafeGuard brand of school bus seats and seatbelts. “[I]nformation that is being provided to the industry is focused on conventional knowledge that applies to the school bus seat vinyl itself, without even always providing all the caveats and precautions that must be considered when going above the fully accepted use of a mild soap-and-warm- water solution wiped on, then wiped and rinsed off with pure warm water, and then dried,” said Charles Vits, market development manager for SafeGuard.
He pointed out that cleaning requirements for belt systems differ from seats and other harder surfaces. “We know that some of these common recommendations for disinfecting can ultimately result in field failures to the restraint system,” he said.
Vits added that the company currently only recommends buckles be cleaned with water, because plastic components inside can become damaged by chemical interactions, which can then lead to occupant restraint failure. He noted, however, that IMMI is currently re- searching the potential development of “an acceptable solution” to disinfecting its products.
A spokeswoman for GOJO Industries, meanwhile, said that without knowing the composition details of the seatbelts from the manufacturer, the company can’t specifically comment on if its Purell Surface Spray would break down the internal plastic materials. But the company has tested “an extensive amount” of plastics that are used in moldable components, said Kelly Ward- Smith, GOJO’s senior manager of public relations. These includes plastics like polyester, nylon, polypropylene, PVC, Polyacrylics, ABS, and more.
“All testing of these specific plastics have shown acceptable compatibility with Purell Surface Spray,” she said. “The plastic materials used as internal and external components of seatbelts, including the strap material, are likely among those which we have successfully tested.”
To avoid rusting uncoated steel, which could be part of the internal components of a seatbelt buckle, Ward-Smith advised spraying surface disinfectant on a paper towel and then wiping the buckle rather than spraying it directly.
While also advising only soap and water, another supplier warned that too much and in the wrong area could be a costly mistake. “Hosing down a bus or using strong chemicals can affect the product or make the floor buckle up and create product failure,” commented Maritza Valentin, a regional sales manager with wheel- chair securement manufacturer AMF-Bruns of America.
She also recommended to make sure to thoroughly dry surfaces afterward.
“Wheelchair lift areas are never to be hosed [down] because the water will sit and create issues on the floor, and the lifts will start to experience failure,” added Valentin, who has 25 years of experience in special needs transportation. “Soaking the floor with a mop can create the same concerns with the floor. A lot of school districts are still running over 10-year-old buses, so some of these buses can be affected [based] on how you clean the inside, especially when it comes to the floor.”
Ken Hedgecock, the national sales manager for the United Safety & Survivability Corporation (USSC), said cleaning school buses should always start with soap and water. But they are no longer enough. And as he pointed out, school bus manufacturer manuals address how to clean vehicles but not how often. The sticking point, so to speak, is what student transporters do after cleaning to ensure that they kill as many bacteria as possible and continue killing them.
AEGIS is another EPA-approved solution to combat vi- ruses that has been used for years in the transit industry as well as in medical facilities and government buildings. Also registered by Health Canada, it is now distributed by USSC for school bus application to treat porous and non-porous surfaces with a bonding anti-microbial agent. An evaluation published in February states that it electrostatically and physically interrupts the bacterial or viral cell membrane and prevents its ability to survive on a protected surface. Hedgecock explained that it “actively attacks” bacteria, viruses and fungi for up to a year with only one application.
“It penetrates the cell membrane of the microbe and kills it. Once applied, it better aids cleaning and disinfecting process,” he shared, adding that future cleaning won’t remove it, until the next application a year later.
Fighting Viruses in the Air
While the CDC and World Health Organization said the novel coronavirus is primarily spread by droplets from someone who is coughing, sneezing or even talking within a few feet away, anecdotal evidence indicates that the SARS-CoV-2 could also be transmissible through particles in the air, according to a May article in Scientific American.
USSC is also working on introducing another solution used in the transit industry to school buses. CDC and state guidance on reopening schools mention the importance of ventilating school buses. Hedgecock said UV photo-hydroionization is a better solution than simply opening windows. UV light (which should never be used on hu- mans and could damage components if shined directly inside a vehicle) works with a catalyst inside an HVAC unit to create vaporized hydrogen peroxide that actively and consistently treats the air as it passes through.
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Of course, such solutions cost money, which is at a premium in school districts, especially for transportation. “The biggest challenge is the word resources,” Hedgecock added. “Where is education going to spend the money it is allotted? If we are going to get our kids to school, we’re going to have to invest in the technology to not only transport them safely but [address] this unseen enemy.”
Meanwhile, school bus HVAC manufacturers American Cooling Technology (ACT) and ProAir seek to introduce their own air ventilation solution. Already used in ambulances to sterilize the air, the technology can be used in school buses by installing the ventilation system in an onboard evaporator, whether that be used for air conditioning or not, said Dave Oberdorff, general manager of ACT.
He explained that the companies are using the base- line of cycling cabin air 12 times an hour through a 3.5-inch-thick HEPA filter, which per U.S. Department of Energy standards must remove 99.97 percent of particles that measure at least 0.3 micrometers. With the virus trapped in the filter, the internal UV light then kills it.
“We agree there has to be cleaning and sanitizing, and airborne filtration must work in conjunction,” he noted.
ACT and ProAir also offer a surface treatment for A/C filters and evaporator coils. “It’s not going to contact all sur- faces,” Oberdorff noted. “The HEPA filter is much denser. But if you get 70 percent [of the virus], it is better than zero. It may be an interim step, if there are budget concerns.”
Then, there is creating a physical barrier to halt the spread of disease. A solution from the Transportation Accessories Group aims to limit the germ transmission between student passengers via plastic curtains that separate rows of school bus seats.
The Original Soft Shield is a removable, soft plastic barrier. Sales literature states that the product can be quickly installed, is durable, and it is easily cleaned.
But student transporters must also do their homework with barriers, as they might not comply with federal motor vehicle safety standards regarding school bus crashworthiness, according to an interpretation issued by the Texas Department of Public Safety. The STARTS Task Force last month noted similar concerns.
Editor’s Note: As reprinted from the July issue of School Transportation News.