By Matt Scallan
The Times-Picayune
ST. CHARLES, La. — St. Charles Parish officials sounded the all-clear alert in the Hahnville area 35 hours after foul-smelling fumes began to escape from a faulty storage tank at Dow Chemical’s St. Charles Operations facility in Hahnville.
The stench from the ethyl acrylate housed in the tank sent at least 27 people to the hospital reporting eye and nose irritation, and forced parish officials to block off parts of River Road near the plant.
Ethyl acrylate is used in producing plastics and adhesives.
The acrid smell, which residents compared to that of burning plastic, drifted over much of the New Orleans area on Tuesday.
Dow workers filled the 640,000-gallon tank with foam to dampen the fumes and treated the material with other chemicals to neutralize it.
Dow spokesman Tommy Faucheux said the material will be loaded onto railcars in the yard, where it will be disposed of in the plant’s normal waste-processing facilities. About 15 families were evacuated from homes closest to the plant overnight as employees of the state Department of Environmental Quality tested the air.
DEQ spokesman Rodney Mallett said Wednesday that DEQ employees with air sampling monitors got no readings close to the federal workplace safety standard for volatile organic compounds of 25 parts per million.
Ethyl acrylate is in that category of chemical.
“None of the samples came up to even half that amount,” Mallett said.
There also is a fixed air quality monitor near the Dow site.
Mallett said he was relying on information from DEQ agents in the field, and did not have immediate access to the data.
One of the characteristics of ethyl acrylate is its pungent smell, which becomes noticeable well below toxic levels.
Some residents near the plant who woke up to the smell and were affected by the odor early Tuesday complained that they were told that nothing serious was going on.
Dow officials said they called the St. Charles Parish Emergency Operations Center about 4:45 a.m., well before firefighters began knocking on doors in the community shortly after 7 a.m.
However, it wasn’t clear what the EOC knew about the full effects of the chemical, which it said was “non life-threatening.”
“We’re going to look at what we did, and we’ll be honest about how we could have done better,” emergency preparedness director Scott Whelchel said.
St. Charles Parish public school officials did not ask summer school and camp participants to evacuate or shelter in place during the event because the EOC didn’t make that recommendation, spokeswoman Rochelle Cancienne-Touchard said.
St. Charles and Dow officials continuously said that the level of ethyl acrylate released, while malodorous, was not toxic.
Plant and parish officials have yet to say just how much ethyl acrylate was leaked.
Parish officials say it could take days for the smell to completely dissipate, but that any residual odors don’t pose a health risk.
Copyright 2009 The Times-Picayune Publishing Company