What is C8 Chemical Contamination?

C8 chemical contamination refers to the environmental presence of specific compounds within the family of perfluoroalkyl and polyfluoroalkyl substances (PFAS), specifically those with an 8-carbon chain (C8) structure. The two chemicals in this family are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). C-8 was originally in production for military applications, as early as the 1940s. And shortly thereafter, manufacturers introduced this highly utilitarian compound into household and commercial products. Today, scientists understand that the widespread use of C8 and subsequent disposal of this chemical into landfills and waterways impact the environment. As a result, various ecosystems, plants, animals, and humans contain increased levels of C8. Furthermore, environmental scientists understand that the chemical C-8 does not easily break down in the environment, nor the body. Consequently, chronic exposure to the chemical can remain in the body for many years and cause adverse health effects. Updated April 9, 2024.

What is PFAS?

PFAS is not one specific chemical, but rather is a broad family of synthetic chemicals characterized by a chain of linked carbon and fluorine atoms. This is a key trait for the substance because carbon and fluorine together form one of the strongest bonds that exist. And the more carbon atoms in the chain, the stronger the structure of the molecule. PFAS comprise a large group of relatable chemicals that exist in many products. For instance: from protective coatings to firefighting foam, and across industries including commercial, industrial, military, and home use. PFAS includes the subset of fluorosurfactants known as C8.

Chemical Exchange

Due to health and environmental issues, manufacturers no longer produce long-chain PFAS. In fact, in the United States, the industries are currently undergoing a phase-out of the long-chain PFAS. And in exchange for the substances comprising eight or more carbons (C8), a shorter-carbon chain “the GenX chemicals” and perfluorobutane sulfonic acid (PFBS) apply.

What is C8?

According to the West Virginia Department of Environmental Protection, C8 has been used by DuPont since the early 1950s in its fluoropolymer-related manufacturing processes. As a result, residues containing C-8 release into the air and discharge into the Ohio River. And other introductions to the environment (such as potential subsurface impact) reportedly occur at production facilities, and also at various sites during destruction/disposal. According to the Centers for Disease Control and Prevention, C8 persists in the environment and does not break down easily.

Perfluorooctanoic Acid C8 PFOA Chemical
Perfluorooctanoic Acid C8 PFOA Chemical


The primary emerging chemicals of concern in the PFAS family include perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). Scientists refer to both PFOS and PFOA, as C8. And both substances were once part of the manufacturing process by companies such as DuPont and 3M, to make products such as Teflon and Scotchgard. And these applications are widespread (for example, non-stick cookware, stain-resistant carpet, and waterproof clothing).

Perfluorooctane Sulfonate C-8 PFOS Chemical
Perfluorooctane Sulfonate C-8 PFOS Chemical

Problems Associated with C8

While the 8-carbon chain structure gives C8 its strength and durability, it also makes it hard to break down naturally, and the human body does not readily metabolize or excrete this type of compound. In fact, C-8 classifies as a “bio-persistent” substance, specifically because it stays in the body this way. The EPA also recognizes that C-8 exposure occurs with people by many different pathways. However, the primal form appears to be the consumption of drinking water and inhaling air.

Adverse Health Effects

The EPA publishes health advisories based on epidemiological studies of human populations with exposure to PFAS. These studies indicate that exposure to C8 over certain levels may result in adverse health effects. For instance, developmental effects to fetuses during pregnancy or while breastfeeding infants (such as low birth weight, accelerated puberty, skeletal variations, etc.) can reportedly occur. Additionally, there are apparent risks of testicular and kidney cancer occurring, as well as other liver effects such as tissue damage. Moreover, there are reportable occurrences of thyroid and immune system effects, such as antibody production impact, as well as cholesterol level changes to the body.

C8 Lawsuit

The death of livestock around Parkersburg, West Virginia was one of the first reasons that C8 was thought to be the cause of illness near the DuPont manufacturing facility. And as a result, a class-action lawsuit was brought against the corporation by residents in 2001. In 2004, DuPont agreed to fund medical monitoring programs, install new water treatment systems, and stand by while a panel of scientists conducted further research on the matter. The panel eventually confirmed a probable link between C-8 and kidney and testicular cancers, ulcerative colitis, thyroid diseases, pregnancy-induced hypertension, and high cholesterol. Members of the class action suit also sued DuPont individually. The first three verdicts were ruled in favor of the plaintiffs, totaling $19.7 million dollars.  And in 2017, over 3,000 remaining cases were settled by DuPont for a total of $670 million.

EPA Action on C-8

In 2006, the EPA created a C8 stewardship program, inviting eight of the top corporations from the PFAS industry to reduce their use of C8 by 95% by the year 2010. The ultimate goal of the program is to eliminate C8 altogether. All of the participating companies, including DuPont and 3M, are reportedly meeting the program goals since commencement. And the chemical C8 is no longer under manufacturing processes in the United States.

2016 EPA Advisory

In 2016, the EPA established health advisories for C-8 based on the agency’s assessment of the latest and best-available scientific data. The EPA’s goals in establishing such guidelines, aim for the contamination testing and monitoring of drinking water. And policies of the guidelines call for remedial action with C8 concentrations exceeding 70 parts per trillion by volume.

What are Gen X Chemicals?

As the chemical of concern, C8, phases out, a new generation of PFAS rises in place by the chemical industry. GenX is the trade name for hexafluoropropylene oxide (HFPO) dimer acid, and its ammonium salt. These chemicals comprise a technology that can also produce non-stick coatings, without the use of C8. These shorter-carbon chains (C6) molecules are a response to the increasing pressure on companies to eliminate C8 from their chemical portfolios. Although GenX chemicals may break down in the environment more easily than their C8 counterparts, they are still proving to be problematic with degradation. Ongoing investigations by the EPA report that GenX substances exist in surface water, groundwater, drinking water, rainwater, and air emissions. Furthermore, oral toxicity studies show that the liver is just as sensitive to GenX chemicals, and the data suggests a link to cancer.

What is PFBS?

Between the years 2000 and 2004, 3M voluntarily phased out PFOS from domestic production. The short-carbon chain replacement for PFOS is perfluorobutanesulfonic acid (PFBS).  This next-gen PFAS boasts a four-carbon-chain structure. As a result, it is far less bio-persistent, and the half-life within humans measures in hours instead of years. Although a cancer link is not confirmable as of the year 2019, scientists do understand that PFBS might also produce risk effects on the kidneys and thyroid. Similarly, PFBS can exist within surface water, wastewater, drinking water, dust, carpeting and carpet cleaners, floor wax, and food packaging.

Further Medical Research

Between 2005 and 2006, over 69,000 participants enrolled in clinical tests to determine C-8 levels in their blood. This event was part of the C8 Health Project, for toxicity and health-risk management. The results indicate mean C8 levels in serum are 500% higher than previous reports for the representative American population. Additionally, scientists observed that C-8 was present in over 97% of participants during the testing timeframe. While a simple blood test can detect C8 in blood serum, it is much more difficult to determine the effects of the chemical in the body.

Low-Level Contamination 

Another challenge is determining the risk of low-level contamination which is now widespread throughout the United States, as well as many other parts of the world. As of 2019, the CDC states that the human health effects from exposure to low environmental levels of C8 are unknown. Nonetheless, ongoing research is still in progress, and new results will continue to unfold.


Written By: Michael Joseph Sabo

Edited By: Adam Azad Kaligi, PG


The United States Environmental Protection Agency (USEPA), Basic Information on PFAS

USEPA Stewardship Program

USEPA Technical PFOS & PFOA Fact Sheet

Center for Disease Control (CDC) PFAS Fact Sheet

California State Waterboard – Information on PFAS 

USEPA Drinking Water Advisory

California Department of Toxic Substance Control (DTSC) – Information on PFAS

West Virginia Department of Environmental Protection – C8

National Institute of Environmental Health Sciences (NIEHS) – Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS)