A letter from Mayor Ronnie Johnston says that independent air quality tests performed for the city from Sept. 17 to Sept. 24 revealed “particularly high levels of ethylene oxide in the neighborhoods adjacent to your facility.” Those levels coincided with a valve leak that occurred between Sept. 15 and Sept. 22. BD alerted the city and the Georgia Environmental Protection Division to the leak after it was discovered and corrected on Sept. 23.
EO levels in the areas near the plant spiked on Sept. 22, according to the report by Montrose Air Quality Services, reaching 15.3 micrograms per cubic meter of air (µg/m3) in one neighborhood and dropping to 0.255 µg/m3 the following day, when the leak was contained. Just outside the plant, levels were 12.3 µg/m3 and 12 µg/m3 on Sept. 22, dropping the next day to 2.9 µg/m3 and 5.51 µg/m3 respectively. Montrose also tested for EO in other areas further from the plant as a control measure.
In all, the tests revealed that the plant had released 54 lbs. of ethylene oxide into the air between Sept. 15 and Sept. 23, according to a City of Covington incident report.
BD had the air on its property in Covington tested by a different company, Ramboll, on the same dates that Montrose conducted the tests for the city of Covington. Ramboll’s results showed a median concentration of 1.2 µg/m3, “well below permissible exposure limits set by the Occupational Safety and Health Administration (OSHA) and the Texas Commission on Environmental Quality (TCEQ), but … greater than the screening value set by U.S. EPA, which does not account for background levels of EtO from other sources, including the human body,” the company said in a news release. “The U.S. EPA screening level is also below detection levels of current air monitoring technology.”
BD’s 2018 permit would have allowed the plant to emit approximately 10,000 lbs. of EO for the year, but BD reported only 656 lbs., company spokesman Troy Kilpatrick previously noted.
In his latest letter, Johnston acknowledged that BD is planning to upgrade its emissions-control equipment, and asks that the company close the plant until those controls are in place and further testing takes place. BD said in August that it planned to spend $8 million to upgrade emissions controls at two medical device sterilization plants it operates in Georgia. BD responded that there is a “fundamental misunderstanding on how to interpret air monitoring results” and offered to “share the perspectives of three toxicology experts that have reviewed both the City of Covington’s and BD’s air monitoring results.”
“No one result can be taken as representative of long-term exposures, nor can short-term sampling provide enough data to determine lifetime risks,” the company added. “Second, when air monitoring values fluctuate up and down at a single spot, that should be noted, and all measurements should be considered when assessing exposures over time, not just the highest value, since long-term health risk generally depends on consistent long-term exposure. In most environmental studies, averaging data points of a single location over time using the geometric mean, is a preferred method of analyzing air monitoring data. This is because health risks are based on consistent exposure over 24 hours a day, 365 days a year for a lifetime, which is considered 70 years. You cannot draw conclusions from any one level on any one day.”
Medtech trade group AdvaMed commissioned Montrose to conduct a separate study of “everyday sources” of ethylene oxide. The study took place Aug. 21 in Ashford, Va. Those sources included a diesel engine, a truck, a gas generator, two gas lawnmowers, a charcoal fire, a wood fire pit, and opened jars of kimchi, kombucha and sauerkraut.
Ethylene oxide is a colorless, odorless gas widely used to sterilize medical devices because, unlike other methods, EO sterilization can take place at low temperatures, it does not harm or discolor the devices, and it can penetrate device packaging better than other sterilants. The federal Environmental Protection Agency declared the gas a carcinogen in 2016.