CORDOVA, Ill.—At a sprawling 3M chemical manufacturing complex here, where the company makes adhesives for Post-it notes, golf clubs and LCD displays, several hundred pounds of a potent climate killer are vented into the atmosphere each day.

The 566-acre facility on the east bank of the Mississippi River, which also makes resins and fluorochemicals, released 73 tons of perfluoromethane (CF4) into the air in 2021, more than any other facility in the country, according to data the company reported to the Environmental Protection Agency. 

Unlike some PFAS, CF4 is considered non-toxic. But when it comes to warming the climate, CF4 is 7,380 times more potent than carbon dioxide on a pound-for-pound basis over a 100-year period. Releases of the fluorocarbon from the plant in 2021 equal the greenhouse gas emissions of 116,000 automobiles. However, unlike the carbon dioxide of car exhaust, which remains in the atmosphere for an estimated 300-1,000 years, CF4 sticks around, warming the planet, for 50,000 years.

Emissions of CF4 from the facility, and their contribution to climate change, may be a tradeoff that the company took to reduce the release of other, more immediately harmful chemicals.

The EPA’s Center for Environmental Measurement and Modeling considers CF4 to be a per- and polyfluoroalkyl substance, or PFAS, a term more commonly associated with nonstick chemical coatings on pots and pans that have been linked to cancer. However, the EPA’s Office of Pollution Prevention and Toxics uses a more restrictive definition for PFAS, which is limited to substances most likely to pose an immediate health concern, and does not include CF4.

3M declined to make anyone available for an interview or a tour of the facility and declined to answer questions about the source of CF4 emissions from the plant.

“As a company, 3M is committed to innovation to decarbonize industry, accelerate climate solutions, and improve our environmental footprint,” Grant Thompson, a spokesperson for 3M said in a written statement. “We continue to deploy the best available technologies to manage our environmental footprint at the site, including our thermal oxidizer which began operations in 2003.”

“They might have been trading one problem for another,” David Cwiertny, director of the Center for Health Effects of Environmental Contamination at the University of Iowa, said of the incinerator. “These PFAS chemicals are difficult to get rid of and it’s possible that some of the control processes that are used to destroy the waste could release other harmful chemicals like CF4.”

“In general, CF4 is known to be a potential by-product of processes that destroy other fluorinated compounds (i.e., CF4 is known to be a product of incomplete combustion),” an EPA spokesperson said in a written statement. 

3M’s Thompson said the intent of the study the company commissioned in 2001 was “to simulate a full-scale hazardous waste incinerator in a laboratory environment and not to determine if incineration would be an effective way to destroy PFOS.” Thompson added that “3M data has not indicated the presence of CHF3 or C2F6”—greenhouse gases that are more damaging to the climate than CF4—in their emissions from the thermal oxidizer.

Thompson said “the thermal oxidizer greenhouse gas destruction removal efficiency is 99.95%.” However, when asked if the 99.95 percent destruction applied to CF4, Thompson did not answer the question, saying only “I don’t have anything else to share with you on this topic at this time.”

A 2019 technical paper on PFAS by the EPA noted that the “most difficult fluorinated organic compound to decompose is CF4, requiring temperatures over 1,400 C.”

3M is not required to destroy CF4 and its air permit for the Cordova facility requires only that its thermal oxidizer operate “at a minimum” of 1,900 degrees Fahrenheit, or 1,038 degrees Celsius.

Thompson did not disclose the operating temperature of the thermal oxidizer. Cwiertny said high-temperature incinerators are expensive to build and operate and added that he did not know if 3M’s thermal oxidizer could operate at more than 1,400 degrees Celsius.

Other potential sources of CF4 from the plant could include leaks from storage tanks if the gas is used as a chemical feedstock, or direct venting into the atmosphere if CF4 is an unwanted byproduct of chemical production, said Denise Trabbic-Pointer, a former environmental manager with DuPont and volunteer with Sierra Club’s Michigan chapter, adding that she didn’t know enough about 3M’s processes to be able to determine the exact source.

An EPA spokesperson said “CF4 is known to be generated as a by-product during production of some fluorinated compounds.”

Whatever the exact source of the emissions, the release of such a potent greenhouse gas from the plant further calls into question whether such chemicals should be produced, said Sonya Lunder, a senior toxics policy advisor with the Sierra Club.

“I don’t think that anyone can make PFAS without producing byproducts that threaten the climate, threaten local drinking water supplies and [threaten] people, either close or distant,” Lunder said. “There’s a dramatic rethinking about whether this family of chemicals is necessary, because it can’t be produced safely.” 

Lunder added that many uses for the chemicals made at 3M’s Cordova plant, like those used in Post-it notes and stain-free carpet coatings, are non-essential and can be replaced with alternatives that don’t compromise human health or the climate.  

CF4 is one of several synthetic, fluorine-containing chemicals known as “the immortals” because of how long they remain in the atmosphere. Once the gases are released, they are “essentially permanent additions to the atmosphere,” the EPA notes.

The pollutant threatens “the public health and welfare of current and future generations,” according to the EPA; however, the agency doesn’t regulate emissions of the greenhouse gas.

“We should be doing everything we can to prevent emissions of CF4,” said Donald Wuebbles, an atmospheric sciences emeritus professor at the University of Illinois in Urbana and a former White House advisor on climate science during the Obama administration. “Any emissions of CF4 are going to drive further climate change and lead to things that are going to affect our planet for many, many thousands of years.” 

The EPA did not respond to a request for comment on why it does not regulate CF4 emissions from chemical plants or whether they had any plans to do so. 

“We will continue to track CF4 emissions through the Greenhouse Gas Reporting Program,” a spokesperson for the agency said. 

On March 16, Illinois Attorney General Kwame Raoul filed a lawsuit against 3M for discharging PFAS waste at the Cordova chemical plant that has contaminated nearby groundwater as well as the Mississippi River.

On Nov. 3, the EPA issued a consent agreement along with 3M requiring the company to “provide treatment to address contamination from per- and polyfluoroakyl substances (PFAS) found in drinking water in the vicinity of 3M’s Cordova, IL facility.”

Neither the state attorney general’s lawsuit nor the EPA’s consent agreement mentioned CF4. Drew Hill, a spokesperson for the Illinois Attorney General’s office, said he could not comment on the pending litigation. 

In a written statement to Inside Climate News, 3M’s Thompson said the emissions data his company reports to the EPA each year “reflects that the Cordova facility continues a downward trend of greenhouse gas emissions over the past decade.”

Greenhouse gas emissions from the plant did drop substantially from 2013 to 2016 but have since plateaued. At the same time, CF4 emissions continued to increase, with the highest annual emissions reported in 2021, the most recent year for which data are available.

On Dec. 20, 3M announced that it will stop manufacturing PFAS and work to discontinue the use of PFAS in its products by the end of 2025. The company makes $1.3 billion annually in net sales of manufactured PFAS, according to 3M. However, long-term legal liabilities from PFAS could cost the company $30 billion, Bloomberg Intelligence estimates; the company’s CEO told Bloomberg that regulatory trends and “consumer unease” with PFAS played a role in the decision. 

Sierra Club’s Lunder expressed cautious optimism at the news. 

“We want you to applaud this move out of PFAS production and want others to follow,” she said. But, “there’s some questions about how 3M is defining PFAS and concerns that they will continue to make harmful fluorochemicals that they define as non-PFAS.”