Sterigenics’ failure to report a leak of ethylene oxide gas on July 31, amid controversy over the Smyrna facility’s emissions of the possibly cancer-causing substance, did not violate state laws due to the small size of the leak, the state Environmental Protection Division has found.

However, Sterigenics has agreed to report all future leaks, no matter the size. And the Sept. 30 EPD determination lists nine previous leaks or other incidents at the plant in recent years, one of which drew an official warning for failure to report. All of those leaks eventually proved to be smaller than reporting thresholds, according to EPD and Sterigenics.

The Sterigenics facility in Smyrna as it appeared in a November 2018 Google Maps image.

Meanwhile, the Smyrna plant remains shut down pending inspections and a new permitting application demanded by Cobb County officials. Air quality testing is underway to determine whether the plant’s typical emissions pose any actual health risk, while concern linger about the effects of previously larger releases of gas in the facility’s decades of operation.

In a written statement, Sterigenics praised EPD’s investigation and said the findings “reaffirm our consistent compliance with applicable rules,” though it did not directly address the previous failure-to-report warning letter.

Sterigenics uses ethylene oxide to sterilize medical equipment.

The July 31 incident, in which the gas leaked from an unclosed valve on a drum, drew community outrage for going unreported despite happening the day after a public meeting about the cancer-risk controversy. An internal company report about the leak was revealed by the Atlanta Journal-Constitution.

Sterigenics previously estimated that less than 6 pounds of the gas leaked from the drum. Under state law, 10 pounds is the threshold at which the company would be legally required to report the leak to the EPD.

The EPD’s investigation report says the company provided documentation that the drum contained 9.3 pounds of the gas prior to the leak. So, whatever the amount the leaked, it was below the reporting requirement and “there is no violation” of the law.

The EPD also requested Sterigenics’ data on the past five years of gas releases, regardless of whether they met the reporting threshold. That found nine leaks or other incidents since 2015, of which two were previously known to EPD. Sterigenics said in a written statement that the amount of gas released in all of those incidents combined is less than 10 pounds.

The dates of the releases include: Feb. 3, Nov. 11 and Nov. 15, 2015; Jan. 31 and June 11, 2017, April 2, July 10 and July 17, 2018; and April 10, 2019.

The EPD had investigated two of the 2018 incidents. In the April 2 incident, EPD learned of the leak from a complaint two days later and believed it to be over 10 pounds, according to EPD investigation documents. The final investigation found that a damaged pipe released about 2.6 pounds of gas over 12 minutes. While the actual amount was below the legal reporting threshold, the law also requires an EPD report of any leak whose amount cannot be determined within 15 minutes. For that reason, an EPD inspector issued Sterigenics a letter of warning for “Failure to Report Hazardous Materials Release.”

“The Environmental Protection Division has determined that you failed to report a release of Ethylene Oxide on April 2, 2018,” the letter reads in part. “… Failure to report future releases will result in the Division seeking enforcement action which could include monetary penalties.”

The other 2018 incident investigated by EPD came on July 10, when some of the gas burned in a spark or flash. One employee was injured, according to an EPD investigation report, but there was no sign of the gas actually leaking.

The EPD said it has requested that Sterigenics file monthly reports of all known releases, regardless of size, and the company says it will.

“Consistent with our commitment to transparency, we have agreed to provide the EPD with monthly reports regarding all known EO [ethylene oxide] releases, including those below reportable levels,” the company said in its written statement.

John Ruch

John Ruch is an Atlanta-based journalist. Previously, he was Managing Editor of Reporter Newspapers.