Chemical company DuPont LLC in LaPlace was fined $480,000 by the Environmental Protection Agency, EPA for failing to install equipment to prevent the release of benzene – a carcinogenic chemical – from its reservoir.

An unannounced inspection of the chemical plant by the EPA two years ago, found leak of benzene into the air at levels more than federal rules permitted, the fine was agreed upon after a consent agreement was reached between EPA and DuPont.

According to the EPA report, inspectors from the agency monitored 77 valves and 2 pumps during the first day of the inspection and found several violations.

There were open-ended lines from valves in different locations that were leaking about 542 ppm of benzene, just above the EPA limit. They measured 20,100 parts per million of benzene leaking from a vent on a benzene waste tank, and 1,933 ppm of benzene leaking out of a second pressure/vacuum valve.

However, DuPont’s official measurements picked up 1,650 ppm being released from the tank, which was less than what was measured by the EPA inspector’s hand-held monitoring device. 

DuPont officials also found 2,030 ppm leaking from the second valve on the tank, and 767 ppm leaking from the uncapped line and nearby valve, both more than EPA measurements.

DuPont is yet to respond to a request for comment. Its Laplace plant manufactures paraphenylenediamine, or PPDA, used in the manufacture of Kevlar, which is used in making bulletproof vests.

Federal law requires major industries to assure that tanks storing benzene have no detectable emissions, which is indicated by readings of less than 500 ppm and visual inspections. 

Short-term exposure to benzene can cause drowsiness, dizziness, headaches, eye, skin, and respiratory tract irritation, and at high levels can cause unconsciousness.