The V.I. Health Department does not expect nearby household water cisterns to have been contaminated from by-products of the fire that erupted at Hovensa Friday afternoon, according to Health Commissioner Julia Sheen.

In a statement, Sheen said the V.I. Department of Planning and Natural Resources’ Division of Environmental Protection dispatched air-monitoring teams to downwind communities. While odors were detected, no immediate health concerns were identified as of Sunday.

According to Sheen, Hovensa officials told Health, VITEMA and DPNR heads that because there was a complete combustion on Friday, no sulfur was released into the air. For that reason, Health officials do no expect that cisterns were impacted, Sheen said Monday.

Chemically speaking, the product of complete combustion of sulfur is sulfur dioxide, which can irritate the respiratory passages if breathed in, but is also a common food additive and preservative, according to numerous chemistry resources available online. Hydrogen sulfide combusts to form water and sulfur dioxide.

Following a Dec. 9 airborne oil release incident at the refinery, Health last week lifted a do-not-drink advisory to neighborhoods near the refinery, saying no contaminants from Hovensa were found in cisterns.

Sheen expanded on that Monday, saying the original do-not-drink advisory was issued as a precautionary measure in the event that products from the release fell into cisterns.

“However, the Department of Health has no knowledge of the maintenance and operation of individual cisterns, which could contain other contaminants that make the water less-than-potable quality,” Sheen said Monday.

“Therefore, we are advising the residents of the affected areas that it is OK to go back to using their cistern water as originally used prior to the DOH press release last December.”

The December press release was issued as a preventive measure because of the potential for contaminants from the release getting into the cisterns. Laboratory analyses obtained recently indicate that those contaminants were not found in the cisterns sampled and the precautionary advisory was lifted.