Source: https://www.delawareonline.com, November 26, 2018
By: Maddy Lauria, Karl Baker and Josephine Peterson

It remains unclear what caused flammable toxic gas to seep into the air from Croda Inc.’s bio-ethanol plant north of New Castle Sunday night, but experts say the decision to close the Delaware Memorial Bridge was the safest bet.

The incident shut down traffic on the bridge for eight and a half hours, the end of the busy Thanksgiving travel weekend.

Delaware Department of Natural Resources and Environmental Control Secretary Shawn Garvin said there were two threats: There were people nearby who could have inhaled the carcinogenic gas, called ethylene oxide, and, it simply could have caught on fire and spread to the cars on the nearby interstate.

“The flammability of it was an issue with it being that close to the bridge and to (Interstate) 295,” he said. ‘It’s more flammable than combustible.”

The structure of the bridge did not appear to be at risk, he said.

Holloway Terrace Fire Chief Mark Willis said a Hazmat crew responded to Croda Inc. in New Castle at about 4 p.m. on Sunday after employees first discovered the leak.

Crews used more than 30,000 feet of hoses to spray water into the air to dissipate the chemical gas, Deputy Chief Rob Snyder said.

The constant water kept the vapor low to the ground, as Croda crews transferred the remaining gas into a secure tank, he said.

DNREC officials at the scene had to close valves to secure the area, Garvin said.

The amount of gas that leaked will be determined after an investigation, he said.

Asked if the leak was caused by a ruptured line, broken valve or rusted tank, Garvin said, “we will be investigating to ensure we have a full understanding of where it came from.”

Garvin said DNREC officials do periodically inspect the facility, though he would not say when the next visit was scheduled.

DNREC inspected the site Aug. 20, four days before it began producing ethylene oxide.

“I’m not sure I can give you a definitive that would say every 6 months, every year, every two years,” he said.

A spokesperson at the U.S. Environmental Protection Agency did not answer questions about the incident by press time.

Ethylene oxide is used to manufacture other chemicals, to sterilize medical devices and as a fumigant, according to the Occupational Safety and Health Administration.

DNREC said it met all the criteria for the ethylene oxide permit.

For residents, the chemical operation was a disruptive neighbor.

On Sunday night in New Castle, residents living near the plant were urged to stay in their homes. Delaware’s emergency management tried to contact residents in Collins Park, Buttonwood, Swanwyck and Castle Hills.

Robin Most described the scent of the gas as “sweet like honeysuckle.” She was stuck on the New Jersey side of the bridge, near exit 1. She said she began having headaches and double vision in the eight and a half hours she was stuck in traffic.

Nearby resident Crystal Robertson had symptoms varying from headaches, to sore throats to burning nose and eyes. Robertson lives on Buttonwood Avenue, a mile and a half from the plant. Her three-week-old daughter’s eyes continuously watered.

“It was beyond scary,” Robertson said. “No one warned us we were in grave danger.”

All north and south lanes of Delaware Memorial Bridge closed around 5 p.m. after Croda officials asked the Delaware River and Bay Authority to shut down the bridge, spokesman Jim Salmon told The News Journal.

The leak was finally, contained and the bridge reopened about eight and a half hours later, and as of Monday, no serious injuries had been reported.

Croda said in its press release following the leak that one employee sought medical treatment “as a precautionary measure” and “is currently under observation.”

The statement also said “there was no point at which there was an unsafe level” of ethylene oxide leaking from the site.

According to the American Chemistry Council, explosions from ethylene oxide vapor clouds, or from the chemical catching on fire, can have devastating – and far-reaching – impacts.

In northern Delaware, this is not the first time highly toxic ethylene oxide has found its way into the atmosphere. Croda previously was cited for releasing 98 pounds of the chemical in 2008, two years after the company acquired Uniqema and the Atlas Point facility.

In Delaware’s latest toxic release inventory from 2016, ethylene oxide ranked fourth for onsite releases of known carcinogens. All of that chemical release – 2,654 pounds – was released into the air by Croda, the report states.

Inhaling ethylene oxide gas for short periods of time can cause headaches, dizziness, nausea, fatigue, coughing, wheezing, shortness of breath, vomiting and other gastrointestinal distress, according to the U.S. Environmental Protection Agency.

In 2016, the U.S. Department of Labor sanctioned Croda for another chemical leak at its New Castle plant. In that incident, an employee suffered burns from “molten” acid called, 12-hydroxystearic.