Boeing tested air purifiers like those widely used in schools. It decided not to use them in planes.

Reviewed by Emily Henderson, B.Sc.Jun 8 2021

Aerospace giant Boeing tested two kinds of ionization technologies — like those widely adopted in schools hoping to combat covid — to determine how well each killed germs on surfaces and decided that neither was effective enough to install on its commercial planes.

Boeing noted in its conclusion that "air ionization has not shown significant disinfection effectiveness."

Companies that make the air purifiers say they emit charged ions, or "activated oxygen," that are said to inactivate bacteria and viruses in the air. Boeing did not test the technology's effectiveness in the air, only on surfaces. It also used a "surrogate" for the virus that causes covid-19.

The Boeing study has been cited in a federal lawsuit filed by a Maryland consumer against Global Plasma Solutions, maker of the "needlepoint bipolar ionization" technology that a Boeing spokesperson said its engineers tested.

The proposed class-action lawsuit says GPS makes "deceptive, misleading, and false" claims about its products based on company-funded studies that are "not applicable to real world conditions."

A GPS spokesperson said the lawsuit is "baseless and misleading" and that the company will aggressively defend against it. He added that Boeing "researchers deemed the study 'inconclusive.'"

"Plaintiff's Complaint throws the proverbial kitchen sink at GPS in the hopes that something might stick," the air purifier company says in court documents filed May 24 as part of its motion to dismiss the proposed class action. "But it is devoid of any concrete, specific allegations plausibly alleging that GPS made even a single false or deceptive statement about its products."

The plaintiff's case cites a KHN investigation that found that more than 2,000 U.S. schools had bought air-purifying technology, including ionizers. Many schools used federal funds to purchase the products. In April, a covid-19 commission task force from The Lancet, a leading medical journal, composed of top international health, education and air-quality experts, called various air-cleaning technologies — ionization, plasma and dry hydrogen peroxide — "often unproven."

Boeing said in its report that with ionization there is "very little external peer reviewed research in comparison to other traditional disinfection technologies" such as chemical, UV and thermal disinfection and HEPA filters, all of which it relies on to sanitize its planes.

The controversy is getting the attention of school officials from coast to coast. They include one California superintendent who cited the lawsuit and switched off that district's more than 400 GPS devices.

For worried parents and academic air-quality experts who regard industry-backed studies with skepticism, the Boeing report heightens their concerns.

"This [study] is totally damning," said Delphine Farmer, a Colorado State University associate professor who specializes in atmospheric and indoor chemistry who reviewed the Boeing report. "It should just raise flags for absolutely everyone."

'No reduction’ in bacteria

GPS pointed to another study, one conducted in the weeks before Boeing began its study in September, by a third-party lab. It completed a study of two devices — powered by GPS technology — that another aviation company now markets to clean the air and surfaces in planes.

That study looked at the effect of the ionizers on the virus that causes covid-19 when used on aluminum, a type of plastic called Kydex and leather. The test report shows it was conducted in a sealed, 20-by-8-foot chamber, with airflow speeds of 2,133 feet per minute — or about 24 mph. At the end of 30 minutes, "the overall average decrease in active virus" was more than 99%.

"Given the specific environment this was tested in, the quality of the materials, and the method in which the virus was dispersed, it is safe to say that the bipolar ionization system used in this experiment has the ability to deactivate SARS-CoV-2 with the given ion counts," the Aug. 7 report from the third-party lab says.

The following month, Boeing began its own testing of GPS devices and another kind of ionization technology.

The Boeing study cites a GPS white paper that says its device killed 99.68% of E. coli bacteria in one test in 15 minutes. GPS records show the test was done on bacteria suspended in the air. The Boeing engineers used the company's technology to try to kill E. coli on surfaces in a lab but found "no observable reduction in viability" after an hour.

The Boeing study notes it "was unable to replicate supplier results in terms of antimicrobial effectiveness."

GPS cautioned that the Boeing tests examined disinfection of surfaces, not the air: "While GPS products do have the ability to help reduce pathogens in air and on surfaces, GPS products are not chemical surface disinfectants."

Yet surface tests comprise half of the test results the company lists on its "pathogen reduction" webpage, a GPS spokesperson confirmed.

Boeing researchers found another lab result they could not replicate: While the GPS white paper reported a 96.24% reduction in Staphylococcus aureus in 30 minutes, Boeing engineers found "no reductions" in the bacteria in an hourlong test.

Boeing found minimal or no reduction on surfaces in four other pathogens it tested with GPS ionizers for an hour in a Huntsville, Alabama, lab.

Notably, Boeing's tests in Huntsville detected no hazardous ozone gas from the GPS unit, the report says. The "corona discharge" ionization technology from another vendor that Boeing also studied did emit ozone at levels that "exceeded regulatory standards."

A University of Arizona lab test described in the Boeing study found that the GPS device showed a 66.7% inactivation of a common cold coronavirus on a surface after an hour of exposure at up to 62,000 negative ions per cubic centimeter. That ion level is far higher than the amount of ions company leaders have said the devices tend to deliver to a typical room. Those levels have ranged from 2,000 to 10,000 and even up to 30,000 ions per cubic centimeter when an HVAC system is running, according to records provided to KHN and statements made by company representatives.

In a presentation during a Berkeley Unified School District meeting in California, a physicist who appeared with executives said a level of more than 60,000 ions per cubic centimeter "has been shown to be not healthy."

GPS noted that Boeing deemed the 66.7% effectiveness rate in killing the common cold virus “statistically significant.” A GPS spokesperson said the result validates needlepoint bipolar ionization's "effectiveness against certain pathogens." In its report, Boeing called the test results "inconclusive" due to "lack of experimental confirmation."

A GPS spokesperson also highlighted a passage in the Boeing report's conclusion that said: "There remains significant interest in air ionization due to lack of byproduct production, minimal risk to human health, minimum risk to airplane materials and systems, and the potential for persistent disinfection of air and surfaces under specific flow conditions."

The Boeing study concluded in January. In April, GPS published the results of additional tests it funded at a third-party lab showing its technology "is highly effective in neutralizing the SARS-CoV-2 pathogen."

Boeing engineers said their study highlights the need for those in the ionization business to standardize the evaluation of the technology "to allow comparison to other proven methods of disinfection."

Ripple effects of the Boeing study

On May 7, law firms representing a man who spent over $750 on a GPS air cleaner in Texas filed the "fraudulent concealment" lawsuit against GPS in U.S. District Court in Delaware.

The lawsuit claims that the defendant's "misrepresentations and false statements were woven into an extensive and long-term advertising campaign … accelerating during the COVID-19 pandemic."

"People are being victimized by these companies for profit," said Mickey Mills, a Houston attorney for the plaintiff. "People are scared because of covid, and they capitalize on it."

In filing a motion to dismiss the case, GPS told the court the lawsuit was an "attempt to distort the facts and assert baseless claims, doing grave damage to GPS's business in the process."

The GPS court document also says the disclaimers on its website "make it unreasonable for any consumers to believe that the efficacy demonstrated in GPS studies will necessarily be the same for their particular application."

It asserts that most of the GPS statements identified in the plaintiff's lawsuit — such as "safe to use" and "cleaner air" — amount to "non-actionable puffery" as they are "vague generalities and statements of opinion."

The lawsuit spurred a Newark, California, school district to turn off its GPS devices, according to a May 18 memo from Superintendent Mark Triplett to district families. The district spent nearly $360,000 on the devices, an April board presentation shows.

The roughly 5,500-student district bought GPS units for every school HVAC system, Triplett said in a March school board meeting in which he noted the technology "arguably is much better than any filter." By May, he said in the memo the district had become aware of the lawsuit "alleging the misrepresentation" of the devices and would continue to monitor the situation.

A company spokesperson noted GPS appreciates Newark's concerns and has reached out to share additional data and answer questions, as well as extended "an offer to conduct onsite testing to verify the safety of this technology and the added benefits."

Megan McMillen, vice president of the Newark Teachers Association and a special education preschool teacher, said it was disheartening to know the cash-strapped district in the Bay Area spent so much on the devices instead of other safety measures or services to mitigate learning loss after the chaotic pandemic year.

"For such a big chunk of that [money] going to something potentially ineffective … is really frustrating," she said.