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Wilmington News Journal
13 April 2003
DuPont confronted over chemical's safety
EPA and W. Va. lawsuit challenge risks posed by C-8, used to make Teflon
By Fred Biddle
Staff reporter
Environmental regulators and a class action lawsuit have challenged the safety of a chemical the DuPont Co. uses to make Teflon, its best-known brand.
As part of an ongoing review of ammonium perfluorooctanoate, also called C-8, the U.S. Environmental Protection Agency recently questioned the research on which DuPont relies to prove that C-8, now unregulated, is safe.
In a written statement last month, the EPA said, "There remains considerable scientific uncertainty regarding potential risks." The agency, which regulates industrial toxic emissions, also said it soon will "announce a series of aggressive steps that it will take to gather additional scientific information."
DuPont also faces a class action lawsuit on behalf of anyone who drank water allegedly contaminated by the chemical. Since DuPont began using C-8 in 1951 at its Washington Works facility on the Ohio River near Parkersburg, W.Va., the company has released waste containing the chemical into the air and river, according to court records. The records say DuPont also dumped some C-8 waste into landfills for years, and at least 30,000 households are served by utilities whose water contained C-8.
DuPont stands by C-8, however, saying the chemical does not harm human beings. The company dismisses studies by 3M Co., the original manufacturer of the chemical, that found it causes cancers and liver damage in rats. It also discounts early observations of birth defects in children of its own employees.
DuPont said the EPA evaluation of C-8 had resulted in "an inappropriate risk assessment."
3M Co. began to phase out the chemical in 2000 and stopped selling it last year, citing its "principles of responsible environmental management."
DuPont started manufacturing C-8 in October at a plant in Fayetteville, N.C., for its own use and for sale. DuPont also has begun to dispose of C-8 waste along the Delaware River as part of its efforts to control the pollution problem on the Ohio River.
DuPont officials said disposing of C-8 waste in Delaware waters poses no environmental risk.
The company ships C-8 contaminated wastewater by train from West Virginia to its Chambers Works plant in Deepwater, N.J. In 1999, the most recent year for which information was available, the company released treated wastewater containing nearly 10,000 pounds of the chemical into the river.
DuPont has been manufacturing limited amounts of Teflon without C-8 for more than a year. But DuPont officials said there is no "safe, technically sound and environmentally protective" way to make Teflon without C-8.
Teflon is a moneymaker
Much is at stake for DuPont. The company is jettisoning many older, commodity chemicals, including nylon, as it tries to increase business such as fabrics made from genetically engineered crops and plastics for TV displays thinner than anything now available.
But most of those businesses are years from turning a profit. Teflon is among the products that help finance that transition, and DuPont is confident Teflon will remain a top product.
Although DuPont would not discuss profits from Teflon, company executive Richard J. Angiullo said in a November deposition that products made using C-8 accounted for $200 million in after-tax profits in 2000.
In recent decades, DuPont has abandoned some of its most profitable products because of health and environmental concerns. Among them are chlorofluorocarbon refrigerants and lead compounds for high-octane gasoline. More recently, it ceased production of Benlate fungicide and has paid more than $1.7 billion as the result of lawsuits over Benlate.
"There is no evidence or data that demonstrates [C-8] causes adverse human health effects," said Anguillo, who is vice president of the DuPont division overseeing most Teflon production.
Angiullo said he is confident about Teflon's future.
Kenneth A. Cook, president of the Washington, D.C.-based Environmental Working Group, a nonprofit environmental group that monitors corporate pollution, has fought with DuPont over contaminated drinking-water wells along the Ohio River. DuPont has withheld information about the dangers of C-8 over the years and continues to under state its danger, he said.
"C-8 is the most persistent chemical ever made, and according to most scientists it has infinite stability in the environment," Cook wrote last month in a letter to West Virginia Gov. Robert Wise. "This means that all of it ever made will keep cycling through the environment and through people - literally forever."
Records detail C-8 dumping
Questions about C-8 first arose at DuPont's Washington Works in West Virginia, where the company uses C-8 to make raw Teflon.
Throughout the 1950s and 1960s, DuPont vented incinerated waste into the air and dumped waste directly into the Ohio River, according to company documents released in a private lawsuit settled in 2001. The company also disposed of it in a landfill. C-8 migrated from those sources into the tap water of surrounding communities, according to the documents.
In the early 1980s, DuPont purchased hilly parcels of West Virginia land owned by brothers Wilbur Earl, Jim and Jack Tennant. In 1984, the company began dumping waste containing C-8 into an unlined landfill in one of the hollows, records show.
An undated, internal DuPont memo among the records listed the pros and cons of dumping C-8 into a landfill on land formerly owned by the Tennants. Among the pros: "easy to do - less expensive." Among the cons: "may not protect groundwater."
C-8 and other toxic chemicals did pollute the groundwater. In 1996, West Virginia fined DuPont a total of $250,000 after regulators reported dead livestock and wildlife near the landfill, and leakage from the unlined landfill into an Ohio River tributary.
The Tennants sued DuPont in July 1999, alleging several hundred cows died after drinking from streams and ponds near the landfill. DuPont settled that case in 2001. Details are confidential, but more than 100,000 pages of company documents disclosed in that lawsuit became the basis of a class-action lawsuit certified last year on behalf of Ohio River Valley residents.
The Cincinnati-based law firm Taft, Stettinius & Hollister has filed the class-action lawsuit against DuPont and the Lubeck Public Service district, the local water utility. The lawsuit alleges that DuPont and Lubek contaminated the region's drinking water. It seeks unspecified monetary damages, monitoring of residents' health and a reduction of C-8 emissions at Washington Works.
DuPont began testing drinking water from businesses and homes in the region in 1984 "to learn more about C-8," Angiullo said. But DuPont said it did not begin to inform the public of what it found until the late 1980s. Levels in DuPont's test ranged as high as 2.2 parts per billion, according to company documents.
"We did not believe we had any reason to be concerned at these levels," Angiullo said.
Bob Griffin, general manager of the Little Hocking, Ohio, water authority, said he had no record of ever having been notified that DuPont had found C-8 in its tap water after testing it.
Last year, the authority closed one of its four drinking water wells after finding C-8 levels of 8 ppb.
Griffin said in a letter to the utility's 12,000 customers in February 2002 that the utility was "shocked" to learn of the contamination.
Cancer, birth defects seen
Studies since the mid-1970s have suggested that C-8 is toxic to animals. But DuPont has said it is harmless to people.
Some of the most critical questions about C-8's toxicity were raised by its original manufacturer. Amid controversy about a family of related compounds, 3M in the mid-1970s began two decades of studies that found C-8 caused cancers in rats whether inhaled, swallowed or absorbed through the skin. The American Conference of Governmental Industrial Hygienists, which recommends exposure standards for most industrial chemicals, agrees C-8 causes cancer in animals. So does the EPA.
Studies of 3M workers over decades, however, have not conclusively linked C-8 to increased mortality or health problems in people.
DuPont said the way cancer develops in rats is different from the way it develops in human beings, and that some chemicals that cause cancer in rats do not cause cancer in people. An early 3M study also found birth defects in the eyes of rat fetuses exposed to C-8.
DuPont removed women from the Teflon operations at Washington Works in April 1981 after learning of the 3M study. DuPont reassigned the women to the plant after conducting its own review, saying 3M's study was flawed.
Before that action, DuPont noted eye and nostril defects in two of the seven children born to the women from 1979-1981, according to an internal memo disclosed during the now-settled lawsuit. DuPont said in a written statement Friday that the internal memo recorded only one confirmed birth defect. "There is no indication that it was caused by exposure to [C-8]," the statement said.
DuPont was responding to a letter the Environmental Working Group wrote Friday to EPA Administrator Christine Todd Whitman alleging that the company violated federal disclosure laws by failing to report birth defects. The EPA didn't immediately comment but is expected to discuss the matter at a press conference Monday in Washington.
Attempts to identify women who worked at Washington Works at the time were not successful.
Forty-eight women of childbearing age now work in Washington Works' Teflon operations. DuPont expects women will work in C-8 production operations in Fayetteville, although none are now. "We have no concerns that would move us to preclude women from working in any areas where C-8 is used," said DuPont's Angiullo.
Although DuPont rejects implications for people from studies showing that C-8 caused cancer in animals, the company in a March 1982 memo cited animal studies to "conclude that female employees of childbearing capability no longer need to be excluded from areas where there is potential for exposure to C-8." They went back to work.
"It's disingenuous for DuPont to pick and choose how it wants to use animal studies," said Kristina Thayer, the Environmental Working Group's chief scientist.
More recent studies have led 3M to abandon C-8 sales and all production but a small amount for its own use.
After studies in 1997 and 1998, 3M concluded there was "an apparent widespread distribution" of C-8 and a closely related compound in the general population. According to studies 3M submitted to the government in 2001, C-8 was detected in the blood of 96 percent of 598 children tested in 23 states and the District of Columbia.
Citing the prevalence of the chemical in humans, 3M in 2000 announced plans to phase out production of C-8 and all related chemicals for commercial sale made at 3M plants in Alabama, Minnesota and Belgium.
3M's precaution cost its shareholders. In addition to losing DuPont and other C-8 customers, it was forced to reformulate Scotchgard, its well-known stain-proofing product for upholstery and other household goods, which contained a closely related compound. That led to a $168 million charge against pretax earnings in 2000. The company pulled several Scotchgard products from the market while reformulating them.
DuPont, however, has cited 3M's ultimate conclusion that C-8 has no ill effects on people. A DuPont spokesman said 3M's decision "wasn't motivated by health concerns."
No safe-exposure limit set
DuPont has considered setting a limit for safe exposure to C-8. Senior DuPont toxicologist Gerald Kennedy proposed in a June 1987 memo, that 0.5 parts per million would be "an acceptable level" for C-8 in the blood of workers.
That year, DuPont recommended that "once a safe level is established, those personnel exceeding 50 percent of this level will be required to be removed from the exposure area," according to another DuPont memo.
But DuPont never adopted a blood-level limit, although it still tests workers.
"There has never been a medical need," said Robert Rickard, director of DuPont's Haskell Laboratory for Health and Environmental Studies
Kennedy wrote to the EPA in January 2001 to report that, among workers tested the previous year, the average exposure was 1.53 parts per million - three times higher than the limit it once considered for workers.
Although DuPont disputes C-8 is a health hazard, since the early 1990s the company has imposed what it calls a "community exposure guideline" of up to 3 ppb of C-8 in water and air in planning how it makes Teflon and controls resulting waste. DuPont calls the voluntary guideline conservative.
"You should not conclude that exposure over that is damaging to health," Rickard said.
In West Virginia, testing of several local wells revealed concentrations far exceeding DuPont's community guideline. One test sample in a Little Hocking well field yielded a level of 78 ppb, utility manager Griffin said.
An October 2001 consent decree between DuPont and the EPA's West Virginia and Ohio regional branches specified DuPont would have to provide temporary alternative sources of drinking water should concentrations of C-8 be found at or above 14 ppb in ongoing testing in the region. The level, since raised to 150 ppb, has been criticized by the Environmental Working Group.
Such high levels haven't turned up in drinking water in tests by a toxicology group commissioned by West Virginia environmental officials.
C-8 production moved
DuPont said it is committed to limiting emissions of C-8 from the Fayetteville plant to 200 pounds annually. Environmental activists said that even that amount may not be safe, given how the chemical lingers in the human body.
In West Virginia, where it uses C-8 to make Teflon, DuPont has installed scrubbers that a spokeswoman said eventually will contain more than 90 percent of C-8 emissions at its Washington Works plant. The company said they totaled just over 20,000 pounds last year, 75 percent less than in 1999.
That's not good enough for the Ohio Environmental Protection Agency. In a Jan. 7, 2003, letter to DuPont, director Christopher Jones said the company's efforts were not sufficient to guarantee that air pollution would continue to decrease. Ohio EPA specifically asked that DuPont work with West Virginia officials to establish and abide by a limit for air emissions.
DuPont also is grappling with how federal regulation would affect its disposal of C-8 waste into the Delaware River and Delaware Bay. As a result of the pollution-control measures at Washington Works, the company has started shipping wastewater containing C-8 by rail to its Chambers Works treatment plant.
"Our effluents are regulated and in compliance with Clean Water Act permits," said DuPont spokeswoman Diane Shomper. The EPA's eventual ruling on C-8 could alter that.
After the EPA's statement last month that further research is needed to establish the safety of C-8, DuPont issued statements defending the chemical and stating Teflon's best known use - in non-stick pans - is safe.
DuPont also said it does not oppose the regulation of C-8.
"Regulation in this case would be most welcome," Angiullo said. "Because it would supply some assurance to society at large" that DuPont is not polluting or otherwise threatening the environment and human health.
http://www.ourstolenfuture.org/Commentary/News/2003/2003-0413-WNJ-dupontc8.htm
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- Dupont Has Known For 50 Years Lapis
20 y
5,636
This is a reply to # 349,261http://www.ewg.org/reports/toxicteflon/es.php
DuPont has known for 50 years
Environmental Working Group reviewed 16 peer-reviewed studies detailing experiments conducted over the past 50 years, showing that heated Teflon decomposes to 15 types of toxic gases and particles. Many of these studies were conducted by DuPont’s own scientists, who began studying heated Teflon (PTFE) in the 1950s when DuPont workers were developing polymer fume fever that the company found could lead to a potentially fatal condition called pulmonary edema [1]. Since DuPont's discovery of polymer fume fever, cases have been reported in the peer-reviewed literature of the same illness stemming from home kitchen exposures [2, 3].
Teflon offgasing studies show that at the design temperatures of conventional kitchen appliances, Teflon chemicals break apart to form the following particulates and gases:
Two chemicals linked to cancer or tumors in laboratory studies (PFOA and TFE);
Two chemicals that are potent global warming gases (PFB and CF4);
Two chemical warfare agents (PFIB and MFA) and a chemical analog of WWII nerve gas phosgene (COF2);
At least two chemicals that have widely contaminated the world (PFOA and TFA), one currently undergoing a rigorous safety review at the Environmental Protection Agency (PFOA);
Four gaseous chemicals and some components of the particulate matter that are highly persistent environmental pollutants, that likely never break down in the environment (TFA, PFOA, CF4, PFB, and the perfluorinated particulate alkanes); and
Four chemicals that are considered highly toxic relative to most other industrial chemicals (PFIB, MFA, COF2, HF).
Studies show that the gases that come off of non-stick pans are complex mixtures that vary in composition with temperature. At any given temperature the gas comprises one or more dominant chemicals, and other chemicals present in trace quantities. In numerous studies scientists have studied mortality in rats and birds exposed to the offgas mixtures, but potential long-term health impacts have not been studied. The government has not conducted a safety study of Teflon cookware. Accumulation of the offgas chemicals in food has not been studied. The potential effects to humans of inhalation exposures have not been studied, but several of the offgas components are considered highly toxic to humans relative to most other industrial chemicals.
DuPont scientists list the hallmark human symptoms of polymer fume fever as tightness of chest, malaise, shortness of breath, headache, cough, chills, temperatures between 100 and 104°F, and sore throat, based on a survey of complaints registered by workers who were struck by the illness [1]. Based on this suite of symptoms, cases of polymer fume fever from home exposures could easily be mistaken for the common flu.
The toxic particles and gases identified as Teflon offgas products, and the temperature at which they are first identified in the studies reviewed, are shown below, with toxicity information that is drawn primarily from high dose animal studies, the only source of information available for most of the chemicals:
1. 464°F - Ultrafine particulate matter [4]: Teflon produces very small (ultrafine) particles which are very toxic, causing extreme lung damage to rats within 10 minutes of exposure. Longer exposures cause death. At higher temperatures, Teflon also produces toxic gases. Some scientists have found that the particles and gases together are responsible for Teflon's toxicity, perhaps because the gases adsorb to the particles, which because of their small size can lodge deep in the lower respiratory tract [5].
2. 680°F - Tetrafluoroethylene (TFE) [6]: The National Toxicology Program considers tetrafluoroethylene (TFE) to be a “reasonably anticipated” human carcinogen because it is known to cause cancer in laboratory animals, but has not been adequately studied in people. In rats, inhaled TFE causes tumors of the kidney tubules, liver, blood vessels in the liver and one form of leukemia (mononuclear). Mice that breath TFE develop tumors of the liver and tumors that develop in blood vessels in the liver or white blood cells [7].
3. 680°F - Hexafluoropropene (HFP) [6]: In people, air exposure to fluorocarbons like HFP can lead to eye, nose and throat irritation; heart palpitations, irregular heart rate, headaches, light-headedness, fluid accumulation in the lung (edema) and possibly death. Long-term exposure in workers is associated with decreased motor speed, memory and learning [8].
In mice and rats, inhalation of hexafluoropropene (HFP) causes kidney lesions, decreased numbers of a type of immune cell (lymphocyte) and increased urination [9]. HFP also causes increased numbers of chromosomal abnormalities in hamster ovaries [8].
HFP can also be added to pesticides as an “inert” ingredient [10], which does not mean that it is non-toxic, but only that is not the pesticide active ingredient. Another example of a pesticide inert ingredient is butyl benzyl phthalate, a chemical well known to cause serious birth defects of the male reproductive system in laboratory animals.
4. 680°F - Trifluoroacetic acid (TFA) [6]: Very few studies have looked at the toxicity of trifluoroacetic acid (TFA), but those that have found decreased growth of fetal rat bone-forming cells (osteoblast) and cartilage cells (chondrocytes) [11], and neural tube defects in rat embryos at high concentrations [12]. Other studies show that HCFC-123, a hydrofluorocarbon that breaks down into TFA, causes enlarged liver and decreased levels of glucose, triglyceride and cholesterol in adult animals. But, it is unclear whether these effects are due to HCFC-123 or a metabolite [13]. A monkey study found the TFA concentration in the fetus was two to six times higher than in the mother’s blood following dosing with HCFC-123 [14].
The long-term environmental impacts of TFA are unknown, but it is extremely persistent and toxic to plants. TFA is also a breakdown product of many hydrochlorofluorocarbon (HCFCs) and hydrofluorocarbons (HFCs) used as replacement for chlorofluorocarbons (CFCs), which are potent ozone depleters used in refrigeration systems, aerosols and other products. Recently, scientists have suggested that high levels of TFA in the environment could be partly due to heated Teflon and other fluoropolymers because measured environmental levels are higher than predicted, based on breakdown of HCFCs and HFCs alone [6].
5. 680°F - Difluoroacetic acid (DFA) [6]: Very little is known about the toxicity of difluoroacetic acid (DFA), although kidney toxicity has been reported in rats [15].
6. 680°F - Monofluoroacetic acid (MFA, fluoroacetic acid or compound 1080) [6]: Monofluoroacetic acid is extremely toxic, doses as low as 0.7 to 2.1 mg/kg can kill people [16]. Initially, people report nausea, vomiting, numbness, tingling, anxiety, muscle twitching, low blood pressure and blurred vision. If exposure is high enough, people can have irregular heart rate (ventricular fibrillation), heart attacks, and severe convulsions leading to respiratory failure [17].
MFA quickly breaks down into a chemical called fluoroacetate. Sodium fluoroacetate was previously used as a powerful rodent killer (rodenticide). In the body, it breaks down into sodium and fluoroacetate, which is responsible for the toxicity. Sodium fluoroacetate kills rodents, and other animals, by inhibiting the tricarboxylic acid (TCA) cycle which transforms energy found in food to energy the body uses. Sodium fluoroacetate also causes heart and respiratory failure, central nervous system Depression and damage to the testes, including decreased sperm production [18].
7. 680°F - Perfluorooctanoic acid (PFOA) [6]: Perfluorooctanoic acid (PFOA) has recently come under significant EPA scrutiny. According to Stephen L. Johnson, Assistant Administrator of EPA's Office of Prevention, Pesticides, and Toxic Substances, the EPA" will be conducting its most extensive scientific assessment ever undertaken on this type of chemical". EPA is concerned about PFOA because it never breaks down in the environment, is found in the blood of over 92 percent of Americans, and is very toxic to rats and monkeys. PFOA causes four types of tumors in rats: liver, pancreas, mammary gland (breast) and testes. PFOA also decreases thyroid hormone levels, a known risk factor for impaired brain development, and delays sexual maturation in laboratory animals. PFOA is especially toxic to the young because it kills young rats at doses that do not kill parental animals. Industry scientists estimate that it takes 4.4 years for people to eliminate just half the amount of PFOA found in their bodies. EPA is taking a close look at PFOA because levels found in the blood of people are too close to levels in rat blood that harm the animals [19, 20].
8. 878°F - Silicon tetrafluoride (SiF4) [21]: Silicon tetrafluoride is a highly toxic, corrosive gas. In the lungs, moisture causes the silicon particles to separate, releasing toxic hydrofluoric acid and also coating the lung with silicon particles. Inhaling hydrofluoric acid can cause eye and throat irritation, cough, difficult breathing, bluish skin color caused by lack of oxygen, lung damage and fluid accumulation in the lung (edema). Long term exposure can cause weight loss, decreased numbers of red and white blood cells (anemia and leukopenia), discoloration of the teeth and abnormal thickening of the bone (osteosclerosis) [22]
9. 887°F - Perfluoroisobutene (PFIB) [23]: Perfluoroisobutene (PFIB) is extremely toxic and inhalation can lead to fluid build up in the lung (edema), a condition that can lead to death. PFIB is listed in the Chemical Weapons Convention as a Schedule 2 compound [24]. PFIB is about ten times more toxic than phosgene, a highly toxic corrosive gas also listed as a chemical weapon. In water, PFIB breaks down into hydrogen fluoride which is also very toxic (see below). Short-term symptoms of PFIB exposure in people include bad taste in mouth, nausea and weakness. Lung edema occurs about one to four hours after exposure, which is life-threatening in some cases, but in most people clears up in about 3 days [25].
10. 932°F - Carbonyl fluoride (COF2) [26]: Breakdown of Teflon (PTFE) in air is the major source of carbonyl fluoride exposure [27]. Carbonyl fluoride is the fluorine version of phosgene, a chlorinated chemical warfare agent. Carbonyl fluoride fumes can irritate eyes, ears and nose. More serious symptoms of exposure include chest pains, breathing difficulty, fluid accumulation in the lungs, weakness, liver damage and increased glucose levels. Because carbonyl fluoride breaks down into hydrogen fluoride and carbon dioxide, it causes many of the same toxic effects as hydrogen fluoride (see below) [27].
11. 932°F - Hydrogen fluoride (HF) [26]: Hydrogen fluoride (HF) is a toxic corrosive gas, and can cause death to any tissue it comes into contact with, including the lungs. The toxicity of HF is due to the fluoride ion and not the hydrogen ion. Breathing HF can cause severe lung damage, such as fluid buildup in the lungs (edema) and inflammation of lung passages (pneumonia) [28].
The fluoride ion (charged particle) is extremely toxic. It is a small ion and weak acid that diffuses quickly and can pass through tissues with relative ease. Fluoride ions inhibit cell respiration, decreasing production of ATP, the major form of chemical energy used by the body. Fluoride attracts cell membranes causing cells to die. The fluoride ion is negatively charged and naturally likes to react with positively charged ions in the body like calcium and magnesium. When fluoride and calcium bind, creating a “precipitate,” a life-threatening condition of decreased calcium (hypocalcemia) can occur. Left untreated, decreases in calcium (and magnesium) can cause abnormal heart rhythm leading to heart attack, muscle spasms and death. Calcium administration is the main treatment for HF poisoning [28].
12. 1112°F - Trifluoroacetic acid fluoride (CF3COF) [21]: Trifluoroacetic acid fluoride is toxic, mostly because it breaks down into hydrogen fluoride, which is very toxic, and trifluoroacetic acid.
The few studies that have looked at the toxicity of TFA found decreased growth of fetal rat bone-forming cells (osteoblast) and cartilage cells (chondrocytes) [11], and neural tube defects in rat embryos at high concentrations [12]. Other studies show that HCFC-123, a hydrofluorocarbon that breaks down into TFA, causes enlarged liver and decreased levels of glucose, triglyceride and cholesterol in adult animals, but it is unclear whether these effects are due to HCFC-123 or a metabolite [13]. A monkey study found TFA in the fetus was two to six times higher than in the mother’s blood following dosing with HCFC-123, a hydrofluorocarbon that breaks down into TFA [14].
Fluoride ion (charged particle) is extremely toxic. It is a small ion and weak acid that diffuses quickly and can pass through tissues with relative ease. Fluoride ions inhibit cell respiration, decreasing production of ATP, the major form of chemical energy used by the body. Fluoride attracts cell membranes causing cells to die. The fluoride ion is negatively charged and naturally likes to react with positively charged ions in the body like calcium and magnesium. When fluoride and calcium bind, creating a “precipitate,” a life-threatening condition of decreased calcium (hypocalcemia) can occur. Left untreated, decreases in calcium (and magnesium) can cause abnormal heart rhythm leading to heart attack, muscle spasms and death. Calcium administration is the main treatment for HF toxicity [28].
13. 1112°F - Octafluorocyclobutane (OFCB) [21]: Octaflurocyclobutane is a fluorine-containing gas that is used in the semiconductor industry, sold as Zyron 8020 by DuPont. According to DuPont, inhaling high levels of octafluorocyclobutane can cause heart beat irregularities, unconsciousness and death. People with pre-existing heart conditions may be extra vulnerable. Only a few toxicity studies in animals are available for octafluorocyclobutane. In one study, rats exposed to a one-time-only inhaled exposure of octafluorocyclobutane lost weight and had abnormal breathing. Dogs that inhaled high concentrations (10-25% air), and were dosed with the stimulant epinephrine, had heart problems. According to DuPont, tests for genetic damage in insects are “inconclusive” [29].
14. 1112°F - Perfluorobutane (PFB, Trade Name CEA-410) [21]: As a global warming chemical, perfluorobutane has a long half-life in the upper atmosphere and has over 8,000 times the global warming potential of carbon dioxide [30]. Perfluorobutane is not as acutely toxic as other PTFE off-gases, but has not been tested for long-term effects.
15. 1202°F - Carbon tetrafluoride (CF4, perfluoromethane) [21]: In addition to being a long-lived fluorinated Teflon “off-gas,” perfloromethane is used in the semiconductor industry, is a refrigerant and propellant and a byproduct of aluminum production. The U.S. government is encouraging these industries to decrease emissions of perfluoromethane because it is a potent greenhouse gas, with a global warming potential almost 6000 times higher than carbon dioxide, and can last in the environment for 50,000 years [30, 31]. In the past, perfluoromethane has been used in pesticides as an “inert” ingredient, [32] a label that has nothing to do with toxicity but only means the ingredient is not the main active pesticide.
Inhaling fluorinated hydrocarbons like carbon tetrafluoride can cause eye, ear and nose irritation; heart palpitations; irregular heart rate; headaches; confusion; lung irritation, tremors and occasionally coma [33].
Next: Heated pans get toxic in minutes
References:
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[9] Environmental Protection Agency (EPA). Fluoroalkenes Test Results; Data submitted by DuPont on Hexafluoropropene (HFP). Office of Prevention, Pesticides & Toxic Substances Data Development (Testing) Policy Avialable online at http://www.epa.gov/oppt/chemtest/fluralke.htm.
[10] Environmental Protection Agency (EPA). List of other (inert) pesticide ingredients. Available online at http://www.epa.gov/opprd001/inerts/lists.html.
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[14] Cappon GD, Keller DA, Brock WJ, Slauter RW, Hurtt ME. 2002. Effects of HCFC-123 exposure to maternal and infant rhesus monkeys on hepatic biochemistry, lactational parameters and postnatal growth. Drug Chem Toxicol 25:481-96.
[15] Lantum HB, Baggs RB, Krenitsky DM, Anders MW. 2002. Nephrotoxicity of chlorofluoroacetic acid in rats. Toxicol Sci 70:261-8.
[16] Key BD, Howell RD, Criddle CS. 1997. Fluorinated organics in the biosphere. Environmental Science & Technology 31:2445-2454.
[17] Hazardous Substances Data Bank (HSDB). 2003. Full record for fluoroacetic acid (CASRN: 144-49-0). Available online at http://toxnet.nlm.nih.gov/.
[18] Integrated Risk Information System (IRIS). 1991. Sodium Fluoroacetate (CASRN: 62-74-8). Available online at http://www.epa.gov/iris/subst/0469.htm.
[19] Environmental Protection Agency (EPA). 2003. Preliminary risk assessment of the developmental toxicity associated with exposure to perfluorooctanoic acid and its salts. March 17, 2003.
[20] Environmental Protection Agency (EPA). 2002. Revised draft hazard assessment of perfluorooctanoic acid and its salts, November 4, 2002. U.S. EPA Administrative Record AR226-1136.
[21] Arito, H and Soda, R. 1977. Pyrolysis products of polytetrafluoroethylene and polyfluoroethylenepropylene with reference to inhalation toxicity. Ann Occup Hyg 20(3): 247-55.
[22] Hazardous Substances Data Bank (HSDB). 2003. Full record for silicon tetrafluoride (CASRN: 7783-61-1). Available online at http://toxnet.nlm.nih.gov/.
[23] Waritz, RS. 1975. An industrial approach to evaluation of pyrolysis and combustion hazards. Environ Health Perspect 11: 197-202.
[24] United States Department of State and Department of Commerce. 2003. U.S. Chemical Weapons Convention Web Site. Site sponsored by the United States Department of State (DOS), Bureau of Arms Control and the United States Department of Commerce, Bureau of Industry and Security (BIS) Available online at http://www.cwc.gov/.
[25] Patocka J, Bajgar J. 1998. Toxicology of perfluroisobutene. The Applied Science and Analysis (ASA) newsletter ISSN 1057-9419 Available online at http://www.asanltr.com/ASANews-98/pfib.html.
[26] Scheel, LD., Lane, WC and Coleman, WE. 1968. The toxicity of polytetrafluoroethylene pyrolysis products including carbonyl fluoride and a reaction product, silicon tetrafluoride. Am Ind Hyg Assoc J 29(1): 41-8.
[27] Hazardous Substances Data Bank (HSDB). 2003. Full record for carbon difluoride (CASRN: 353-50-4). Available online at http://toxnet.nlm.nih.gov/.
[28] International Programme on Chemical Safety (IPCS). 1995. Hydrogen Fluoride (CASRN: 7664-39-3). Available online at http://www.inchem.org/documents/pims/chemical/hydfluor.htm#PartTitle:1.%20%20...
[29] DuPont. 2002. Material Safety Data Sheet (MSDS) for Zyron (octafluorocyclobutane CASRN 115-25-3). Available online at msds.dupont.com/msds/pdfs/EN/PEN_09004a2f800a5e88.pdf.
[30] Environmental Protection Agency (EPA). Global Warming Potentials of ODS (Ozone Depleting Substances) Substitutes. Available online at http://www.epa.gov/ozone/geninfo/gwps.html.
[31] State Department. Mitigating climate change: methane and other greenhouse gas programs. Available online at http://www.state.gov/www/global/oes/97climate_report/part4b.html.
[32] Environmental Protection Agency (EPA). 1998. Inert ingredients no longer used in pesticide products. Federal Register (Volume 63, Number 121):Page 34384-34390 Available online at http://www.epa.gov/fedrgstr/EPA-PEST/1998/June/Day-24/p16571.htm.
[33] Hazardous Substances Data Bank (HSDB). 2003. Full record for tetrafluoromethane (CASRN: 75-73-0). Available online at http://toxnet.nlm.nih.gov/.
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- Teflon Off-gass Studies Lapis
20 y
4,952
This is a reply to # 349,261Teflon offgas studies
Over the past five decades scientists from DuPont, government, and academia have published studies documenting temperatures at which non-stick cookware coatings begin to break apart, offgasing chemicals and particulate matter into the air. Dealing with multiple cases of polymer fume fever in their workers, DuPont scientists conducted a series of studies beginning in the 1950s to identify the toxic components from heated Teflon, killing birds and rats in efforts to understand the potency of the gases and particles.
Teflon Decomposition Products:
Studies show that thermal degradation of Teflon leads to the slow breakdown of the fluorinated polymer and the generation of a litany of toxic fumes including TFE (tetrafluoroethylene), HFP (hexafluoropropene), OFCB (octafluorocyclobutane), PFIB (perfluoroisobutane), carbonyl fluoride, CF4 (carbon tetrafluoride), TFA (trifluoroacetic acid), trifluoroacetic acid fluoride, perfluorobutane, SiF4 (silicon tetrafluoride), HF (hydrofluoric acid), and particulate matter. At least four of these gases are extremely toxic - PFIB, which is a chemical warfare agent 10 times more toxic than phosgene (COCl2, a chemical warfare agent used during World Wars I and II), carbonyl fluoride (COF2 which is the fluorine analog of phosgene), MFA (monofluoroacetic acid) which can kill people at low doses, and HF, a highly corrosive gas.
Many of the thermal degradation products are unmatched in their environmental persistence. Besides fire and heating, which are not considered normal methods of environmental degradation, some of these compounds have no known degradation methods, including four gaseous chemicals (TFA, PFOA, CF4, PFB) and some components of the particulate matter that are highly persistent. TFA and the other PFOA-like perfluorinated acids that have been detected in Teflon degradation studies have “no known significant loss mechanism” [1]. In addition, the perfluorinated alkene HFP, which makes up the bulk of the degradation products at temperatures above 680°F (360°C), will react with OH radicals in the troposphere to produce TFA with 100% conversion [2].
The lowest temperature at which nonstick coatings have been reported to kill birds in a peer-reviewed study is 396°F (202°C) [3]. In May 1998, poultry researchers at the University of Missouri recorded 52 percent mortality in 2400 chicks within three days of the birds being placed into floor pens with new PTFE-coated heat lamp bulbs. After ruling out bacterial infections like E. Coli and Salmonella, or toxic gases such as sulfur dioxide, carbon monoxide and carbon dioxide, the scientists finally linked the chick deaths to offgas products from the PTFE-coated bulbs. All of the chicks examined after death had lung lesions and moderate to severe pulmonary edema consistent with “PTFE toxicosis.”
The researchers also learned from a private communication with Dr. Bedros Nersessian that a duck research facility that used the same PTFE-coated heat lamps had 23.3 percent death in ducklings, over 400 ducklings in all, within five days [3]. In 1997, two English veterinarians reported a case in which eight raptor deaths over three months were attributed to PTFE coated heat lamps. This incident was described in a letter on PTFE toxicity in birds published in the journal Veterinary Record [4]. In addition, an inadvertent poisoning of pet birds has been reported when a Teflon-coated surface was heated to 325°F (163°C). | View Bird Death Diaries
These reports and personal accounts indicate that Teflon offgases toxic substances at temperatures as low as 396°F and 325°F. In 1991, a report by a collaborative team of DuPont and Louisiana State University scientists also addressed this issue. These scientists generated low molecular weight PTFE by heating Teflon to high temperatures and allowing the fumes to age for a few minutes; aging allowed the chemicals in the fumes to react to form small Teflon molecules. The scientists found that when this low molecular weight PTFE was reheated to 464°F two out of three exposed rats died. Evidence indicated that particulate matter was responsible for the rats’ death, and this particulate matter was composed of small molecules of Teflon [5].
Seidel and coworkers explain that “fumes generated at temperatures below 572°F (300°C) are formed exclusively by sublimation of a low MW (molecular weight) fraction already present in the polymer”[5]. From the Seidel study we can conclude that at low temperatures PTFE offgases particulate matter which is composed of small molecules of PTFE. We can also conclude that this particulate matter, which has been reported to cause bird deaths at temperatures below 500°F (260°C), is the result of the presence of low molecular weight PTFE.
This low molecular weight PTFE may be present in Teflon at the time of Teflon’s manufacture, or the PTFE may be created when a pan is heated repeatedly and the coating degrades as PTFE bonds break. PTFE particles have been measured in offgas products at temperatures as high as 1067°F (575°C).
According to Waritz's 1975 paper, particulate matter is emitted from Teflon pans between 554°F and 1067°F (290 and 575°C)[6]. These particles have been linked to bird deaths that can occur when an empty pan is heated on a burner. At these temperature the Teflon molecule breaks apart into smaller Teflon particles. When this occurs the carbon-carbon bonds of Teflon break, generating free radicals; these free radicals can then form alkenes, or they can react with oxygen to form carboxylic acids (forming PFOA, a chemical for which EPA is considering regulatory action, and PFOA-like compounds). The resulting particulate matter is thus a mixture of perfluorinated alkanes, perfluorinated alkenes, and perfluorinated acids [3, 7].
Many studies have established the toxicity of particulate matter generated at temperatures above 554°F (290°C). A study conducted by Zapp et al. in 1955 first indicated that particulate matter was implicated in the toxicity of PTFE [8]. In 1959, Clayton et al. found that PTFE resins will generate toxic products when heated in air. Clayton showed that the particulate matter is toxic when he demonstrated that the toxicity of the offgas products is removed when the PTFE offgas products are filtered to remove the particulate matter before animal exposure [9].
In 1968, DuPont scientists Waritz and Kwon showed that rats exposed to a 20 gram sample of PTFE heated to 842°F (450°C) produced death within four hours. The authors note that "exposures lasted four hours unless all rats exposed succumbed earlier," [10] but they failed to report the time to death among the rats. It was found that when the particulate matter was filtered from the offgas products before the rats were exposed, the mortality was reduced to zero; this provides evidence that the particulate matter is required for toxicity at 842°F. Based on the concentrations of particulate matter that caused rat death, Waritz and Kwon calculate that particulate matter is lethal at concentrations of only 1.4 parts per million (ppm) [10].
In a 1975 study by Waritz, Teflon breakdown products generated at lower temperatures were determined to cause death. Within four hours of exposure to a Teflon-coated pan heated to 536°F (280°C) parakeets died, and quail were killed when the pan was heated to 626°F or 330°C. These temperatures are easily accessible on a stovetop. Rats were killed within four hours when a Teflon pan was heated to between 797°F and 842°F (425 to 450°C). Once again, the DuPont scientist failed to report the time to death for the animals [6].
Many gases are also evolved when Teflon is heated. Heated to temperatures between 680 and 1112°F (360 to 600°C), Teflon generates TFE [1, 11]. This chemical is one of 174 chemicals that the National Toxicology Program considers to be reasonably anticipated human carcinogens [12]. Teflon heated to between 680 and 1202°F (360 and 650°C) will also generate HFP [1, 11]. Carbonyl fluoride, COF2, a toxic gas and the fluorinated cousin of the chemical warfare agent phosgene, is emitted from Teflon that is heated between 824°F and 1292°F (440 and 700°C) [6, 11]. PFIB, perfluoroisobutene, a chemical warfare agent that is ten times more toxic than phosgene, is detected when Teflon is heated in air between 887°F and 1004°F (475 and 540°C) [6]. Above 1202°F (650°C), carbon tetrafluoroide and carbon dioxide are the major products generated during the decomposition [7].
Other chemicals that have been detected in the offgas products of heated Teflon are trifluoroacetetic acid (TFA), difluoroacetic acid (DFA), and monofluoroacetic acid (MFA, also known as compound 1080, a pesticide and historical chemical warfare agent which has an LD50 of 0.7 – 2.1 mg/kg in men [13]), and various other perfluorinated acids with the general formula CF3(CF2)nCO2H; these acids were detected by University of Toronto scientists Ellis and Mabury (and coworkers) in a 2001 study in which Teflon was heated to 680°F (360°C) for 2 hours [1]. Finally, in the presence of glass (SiO2), SiF4 has been detected in the offgas products when teflon is heated to temperatures of 878°F (470°C)and higher [7, 11]; SiF4 is also a toxic gas and it has been reported that the presence of SiF4 enhances the toxicity of the other toxic Teflon offgas products [14].
In a recent PTFE rat toxicity study, Dr. Carl Johnston et al. found that neither the ultrafine particles or the gases produced by PTFE are toxic by themselves, but the two together are extremely toxic together [15]. The authors suggest the particles are acting as carriers for absorbed gas particles, allowing the gas particles to travel to the lower respiratory tract and cause severe damage. Alternatively, the particles could be generating toxic reactive groups on their surfaces. Also, the size of the particles matters. The most toxic particles are called ultrafine and are 16 nanometers in diameter. If the particles are able to coagulate and form larger particles, greater than 100 nm, they are not as acutely toxic to rats.
In one case of human polymer fume fever in the literature, the author reports a case in which a person developed polymer fume fever about one hour after a non-stick pan overheated. Five cockatiels in the house died within 30 minutes [16]. In another case, a healthy 26-year-old woman went to the hospital complaining of difficult breathing, chest tightness and cough after being exposed to toxic fumes coming from a defective microwave oven part: a melted and scorched Teflon block used as an axle for a rotating platform in the oven. At the hospital, doctors noted that her heart was racing, and she had high blood pressure, increased white blood cell count (leukocytosis) and was breathing heavily. An X-ray showed she had “diffuse pulmonary infiltrate.” Her lung function was still abnormal a month later. This woman's two pet parakeets died within minutes of being exposed to the Teflon fumes [17].
Next: DuPont misleads consumers, intimidates bird community
References:
[1] Ellis, DA., Mabury, SA., Martin, JW and Muir, DC. 2001. Thermolysis of fluoropolymers as a potential source of halogenated organic acids in the environment. Nature 412(6844): 321-4.
[2] Machino, M. 2000. Atmospheric chemistry of CF3CF=CF2: kinetics andmechanism of its reaction with OH radicals, chlorine atoms, and ozone. J. Phys. Chem. A 104: 7255-7260 (As cited in: Ellis, DA., Mabury, SA., Martin, JW and Muir, DC. 2001. Thermolysis of fluoropolymers as a potential source of halogenated organic acids in the environment. Nature 412(6844): 321-4).
[3] Boucher, M., Ehmler, TJ and Bermudez, AJ. 2000. Polytetrafluoroethylene gas intoxication in broiler chickens. Avian Dis 44(2): 449-53.
[4] Forbes, NA and Jones, D. 1997. PTFE toxicity in birds. Vet Rec 140(19): 512.
[5] Seidel, WC., Scherer, KV, Jr.., Cline, D, Jr.., Olson, AH., Bonesteel, JK., Church, DF., Nuggehalli, S and Pryor, WA. 1991. Chemical, physical, and toxicological characterization of fumes produced by heating tetrafluoroethene homopolymer and its copolymers with hexafluoropropene and perfluoro(propyl vinyl ether). Chem Res Toxicol 4(2): 229-36.
[6] Waritz, RS. 1975. An industrial approach to evaluation of pyrolysis and combustion hazards. Environ Health Perspect 11: 197-202.
[7] Coleman, WE., Scheel, LD and Gorski, CH. 1968. The particles resulting from polytetrafluoroethylene (PTFE) pyrolysis in air. Am Ind Hyg Assoc J 29(1): 54-60.
[8] Zapp, JA., Limperos, G and Brinker, KC. 1955. Toxicity of Pyrolysis Products of Teflon Tetrafluoroethylene Resin. Amer. Indust. Hyg. Assoc., Annual Meeting, May 1955. (As cited in: Waritz, RS and Kwon, BK. 1968. The inhalation toxicity of pyrolysis products of polytetrafluoroethylene heated below 500 degrees centigrade. Am Ind Hyg Assoc J 29(1): 19-26).
[9] Clayton, JW., Hood, DB and Raynes-Ford, GE. 1959. The Toxicty of the Pyrlysis Products of Teflon TFE-Fluorocoarbon Resins. Amer. Indust. Hyg. Assoc. Annual Meeting, May 1959. (As cited in: Waritz, RS and Kwon, BK. 1968. The inhalation toxicity of pyrolysis products of polytetrafluoroethylene heated below 500 degrees centigrade. Am Ind Hyg Assoc J 29(1): 19-26.
[10] Waritz, RS and Kwon, BK. 1968. The inhalation toxicity of pyrolysis products of polytetrafluoroethylene heated below 500 degrees centigrade. Am Ind Hyg Assoc J 29(1): 19-26.
[11] Arito, H and Soda, R. 1977. Pyrolysis products of polytetrafluoroethylene and polyfluoroethylenepropylene with reference to inhalation toxicity. Ann Occup Hyg 20(3): 247-55.
[12] National Toxicology Program (NTP). 2002. 10th Report on Carcinogens. http://ehp.niehs.nih.gov/roc/toc10.html.
[13] Key, BD., Howell, RD and Criddle, CS. 1997. Fluorinated organics in the biosphere. Environmental Science & Technology 31(9): 2445-2454.
[14] Scheel, LD., Lane, WC and Coleman, WE. 1968. The toxicity of polytetrafluoroethylene pyrolysis products including carbonyl fluoride and a reaction product, silicon tetrafluoride. Am Ind Hyg Assoc J 29(1): 41-8.
[15] Johnston, CJ., Finkelstein, JN., Mercer, P., Corson, N., Gelein, R and Oberdorster, G. 2000. Pulmonary effects induced by ultrafine PTFE particles. Toxicol Appl Pharmacol 168(3): 208-15.
[16] Blandford, TB., Seamon, PJ., Hughes, R., Pattison, M and Wilderspin, MP. 1975. A case of polytetrafluoroethylene poisoning in cockatiels accompanied by polymer fume fever in the owner. Vet Rec 96(8): 175-8.
[17] Zanen, AL and Rietveld, AP. 1993. Inhalation trauma due to overheating in a microwave oven. Thorax 48(3): 300-2.
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- Dupont's Spin Lapis
20 y
4,648
This is a reply to # 349,261DuPont misleads consumers, intimidates pet bird owners and groups
DuPont has repeatedly misled consumers about the safety of their products, publishing misleading information, obscuring important safety warnings, and intimidating bird-related websites which provide pet owners with warnings about the dangers Teflon poses to pet birds.
In a recent news release, DuPont claimed that its coating remains intact indefinitely at 500°F: "DuPont non-stick coatings will not begin to deteriorate until the temperature of the cookware reaches about 500 degrees F, (260 degrees C), and significant decomposition of the coating will occur only when temperatures exceed about 660 degrees F (340 degrees C). These temperatures alone are well above the normal cooking range" [1][2]. Experiences of consumers whose birds have died from fumes generated at lower temperatures show that this is not the case. In one case researchers at the University of Missouri documented the death of about 1,000 broiler chicks exposed to offgas products from coated heat lamps at 396°F [3]. In another case a bird died after its owner preheated a new Teflon-lined oven to 325°F [4][5].
DuPont also claims that human illness will be produced only in cases involving gross overheating: "In cases where non-stick coating is grossly overheated (any food would have long been burned to an inedible state at this point), fumes may produce temporary flu-like symptoms." [2]. Yet DuPont's own scientists have concluded that polymer fume fever in humans is possible at 662°F, a temperature easily exceeded when a pan is preheated on a burner or placed beneath a broiler, or in a self-cleaning oven [6].
Although DuPont has known of the particular susceptibility of birds to Teflon offgas products for decades, and the hazards Teflon poses to pet birds in the home, the company recently employed intimidation tactics to stop bird-related websites from discussing the toxicity of Teflon fumes to birds, impressing one Webmaster to the point that he changed all mentions of "Teflon" in his public service messages on bird safety to "a product whose name I can no longer use due to its trademark."
>>| Read a letter sent to a bird owner from DuPont
DuPont publicly acknowledges that Teflon can kill birds, but the company-produced public service brochure on bird safety discusses the hazards of ceiling fans, mirrors, toilets, and cats before mentioning the dangers of "PTFE" fumes at the bottom of the two-page brochure ("Teflon" is not mentioned) [7].
Next: The government has failed to study Teflon’s safety
References
[1] DuPont 2001. University of Toronto Study and Cookware Safety. Accessed online at http://www1.dupont.com/NASApp/dupontglobal/corp/index.jsp?page=/content/US/en_US/news/position/cookware_safety.html. May 11 2003.
[2] DuPont 2003. "Consumer products help: Cookware safety. Will cooking fumes generated while cooking with non-stick cookware harm people or animals, especially pet birds?" Accessed online May 10 2003 from http:/www.teflon.com.
[3] Boucher M, Ehmler TJ, Bermudez AJ. 2000. Polytetrafluoroethylene gas intoxication in broiler chickens. Avian Dis 44:449-53.
[4] Stewart Bob. 2002. Personal communication with Dr. Jennifer Klein, Environmental Working Group. May 9, 2002.
[5] Stewart Bob. 2002. Personal email communication with Anne Morgan, Environmental Working Group. [date]
[6] Waritz, R.S. 1975. An industrial approach to evaluation of pyrolysis and combustion hazards. Environ Health Perspect 11:197-202.
[7] DuPont 2003. "Making a safe home for your bird," written by Peter S. Sakas. Accessed online May 8 2003 from http://www.dupont.com/teflon/newsroom/bird.html.
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Government Failure In Teflon Studies Lapis
20 y
4,662
This is a reply to # 349,261The government has never rigorously studied the safety of Teflon pans. The Food and Drug Administration approved Teflon as a Food Contact Substance in 1960 after reviewing a hamburger frying study in which elevated levels of fluorinated compounds were found in the hamburger fried on Teflon. FDA judged these levels to be of little health significance. After a prominent Midwestern paper reported on cases of bird deaths and human polymer fume fever, the Consumer Product Safety Commission stated that the Commission would investigate only upon receiving a formal complaint with underlying data. CPSC failed to ban Teflon-coated drip pans, which can reach 1000°F, even after well-publicized poisoning incidences.
http://www.ewg.org/reports/toxicteflon/governmentfailing.php
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- Dupont Has Known For 50 Years Lapis
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