​On January 28, 2021, Illinois EPA issued four statewide Health Advisories for Per- and Polyfluoroalkyl Substances (PFAS) as a result of an ongoing sampling initiative of PFAS chemicals in Illinois community water supplies. A Health Advisory is a regulatory action that provides guidance to local officials and community water supply operators in protecting the health of water consumers. Illinois EPA is authorized to issue a Health Advisory when there is a confirmed detection in a community water supply well of a chemical substance for which no numeric groundwater standard exists.

Illinois EPA uses methodology and toxicity data, outlined in 35 Illinois Administrative Code Part 620, to derive health based protective values. At this time, no enforceable federal or state drinking water standard, called a Maximum Contaminant Level or MCL, exists for any of the more than 5,000 known PFAS chemicals. Illinois EPA is in the process of collecting data in the PFAS Investigation Network to develop a state MCL. 

The table below shows the PFAS chemicals for which Illinois EPA has established Health Advisories.


PFAS Analyte
AcronymHealth-Based Guidance Level 
​Perfluorobutanesulfonic acid​PFBS​140,000
​Perfluorohexanesulfonic acid​PFHxS​140
​​Perfluorooctanoic acid
​Perfluorohexanoic acid


Health Advisories serve several purposes as outlined 35 Ill. Adm. Code 620.601(a) – (d).  Health Advisories are to be used by the Illinois EPA when evaluating groundwater cleanup, when developing future rulemaking proposals, evaluating mixtures of chemical substances and when determining whether a community water supply is taking its raw water from a site or source consistent with regulatory requirements. In addition to the uses outlined in the regulations, the Health Advisories also contain general information on the characteristics of the harmful contaminant, potential adverse health effects and numerical contaminant guidance levels.  The guidance levels contained in the Health Advisories represent concentrations in drinking water at which no adverse health effects are expected to occur.  Additional information on the potential health impacts of PFAS can be found on our Per- and Polyfluoroalkyl Substances (PFAS) webpage.

Documents and Links

News Release: Illinois EPA Issues Health Advisories for Per- and Polyfluroalkyl substances (PFAS) in Accordance with Illinois Groundwater Regulations
Health Advisory - Perfluorobutanesulfonic Acid (PFBS)

Health Advisory - Perfluorohexanesulfonic Acid (PFHxS)

Health Advisory - Perfluorooctanoic Acid (PFOA)

Health Advisory - ​Perfluorohexanoic Acid (PFHxA)