Petroleum compounds have a number of components that can cause health and environmental effects. Sulfolane is a solvent used in the oil refining process to make gasoline. Since sulfolane has not been not a federally-regulated drinking water contaminant, neither the state nor federal government has established maximum contaminant levels of sulfolane for drinking water. The federal Agency for Toxic Substances and Disease Registry (ATSDR) has recommended 25 parts per billion sulfolane as the most protective level for drinking water.

If your water well results showed above 25 parts per billion sulfolane, we advise you not drink the water. Flint Hills is providing bottled water to all residents with impacted wells and working toward a permanent alternate water supply. The Alaska Division of Public Health will also prepare a health consultation to explain the implications of sulfolane consumption at the levels found in North Pole well water. Please feel free to contact them with your health-related concerns and questions about this site (see box at right).

The most likely way in which neighbors of the refinery could be exposed to sulfolane would be through drinking contaminated well water. Given the concentrations of sulfolane reported to date, other uses of well water such as bathing/showering, laundering clothes, and washing dishes are not likely to pose any risk to well water users. Additionally, other exposure routes such as breathing vapors or direct skin contact are unlikely because the chemical has low volatility and is not absorbed through the skin.

The health effects of sulfolane have not been studied in humans. Laboratory animals exposed to very high levels have shown changes to the liver and other organs, and the nervous and immune systems. Tests for carcinogenic (cancer) effects have not been done.

The Alaska Division of Public Health is committed to working with communities impacted by environmental contaminants to address their health concerns. In November of 2009 they asked the federal Agency for Toxic Substances and Disease Registry (ATSDR) to help review the health effects research and advise on a recommended limit for sulfolane in drinking water. The ATSDR report was released on February 9, 2010, and is available on our reports page, along with a companion document prepared by the Alaska Division of Public Health.

Gardening Study

The Technical Project Team plans to collaborate on a pilot study of garden crops this summer using selected gardens in North Pole where well water has been affected by sulfolane. If you grow vegetables and/or fruits and want to be part of this study, please fill out this downloadable questionnaire (88K) and send it to the address given. You can also contact Nim Ha directly by phone (269-8028 in Anchorage) or e-mail (nim.ha@alaska.gov) if you’re interested in participating or have any questions about the gardening study.  Please help us spread the word about volunteering for this important study!