Archive for the ‘Perfluorinated compounds’ Category

Chasing Molecules excerpt explaining the ethylene tree branch of perfluorinated compounds. It’s our whole economic model that needs to be re-designed. Munition technologies have evolved significantly.

(Always remember that DuPont’s nickname was “The Merchants of Death” in the early 1900s for a reason)

Chapter 7: Out of the Frying Pan
Excerpt on Perfluorinated compounds (PFCs)

“This scenario of new materials with comparable intrinsic hazards being offered as alternatives to restricted products is now being repeated with perfluorinated compounds (PFCs). This is a family of compounds from an alphabet soup of names that are used to create non-stick, stain-repellant, and waterproof surfaces and films for both industrial and consumer applications—compounds so widely used that the EPA describes human exposure to these chemicals as “ubiquitous.” Perfluorinated compounds also provide an illustration of how difficult it is under our current chemical regulatory system to find out what is in a commercially marketed synthetic chemical even when it’s being used in contact with food or in products that touch our bodies. They also clearly demonstrate why it’s so important to ask questions about new materials’ biochemical behavior, molecular structure, and behavior—and not simply about performance and expedient production—as they’re being designed for a pharmaceutical or a frying pan.

Among this class of synthetic chemicals that we’ve been wrapping around food, sitting on, and wearing are substances that have been linked to impaired liver and thyroid function, immune and reproductive system problems, altered production of genetic proteins involved in cellular development, to tumor production in lab animals, and to elevated cholesterol levels in children, as well as to changes in metabolism, including how the body processes fat. These compounds are endocrine-disrupting properties and have been linked to cancer.

These perfluorinated chemicals—also sometimes referred to as perfluorocarboxylates (PFCAs) or fluoropolymers—are physically long chain molecules, made up predominantly of carbons and fluorines, in which the carbons are surrounded by fluorine atoms. (In chemistry, the prefix “per” describes a molecule that has the maximum amount of a particular element for its configuration. In the case of PFCs, each molecule has as many fluorine atoms attached as that structure can support.) Their varying lengths and structures depend on how, by whom, and for what purpose they are manufactured. This combination of elements makes strong, flexible, liquid-resistant, and slick-surfaced polymers. They are used as photoresist compounds in semiconductor manufacture, as fire-fighting foams, as insulation in plastics that sheathe wires and cables, as grease-resistant coating on pizza boxes, takeout food containers, microwave popcorn bags, and other packaging, including the support cards in candy and bakery items. They’re also used to make carpets, upholstery, and clothing fabrics (including leather) stain- and water-resistant—and are even added to toilet cleaner.

Among these compounds is one known as perfluorooctane sulfonate (FPOS). PFOA—made with eight carbon atoms and sometimes referred to as C8—is an ingredient of yet another per fluorinated compound called polytetrafluoroethylene (PFTE) that made up the original formulation of the products sold under the names Teflon, Gore-Tex, and Scotchguard. The structure that makes PFOA, PFOS, and PFTE so strong and durable also means that they resist degradation in the environment. They do so to such an extent that, like other persistent pollutants, they are chemical globetrotters. They are being found in Arctic animals, both fish and mammals—including polar bears—as well as in ice and snow. They’ve been found in Lake Ontario trout, in bird eggs collected along the Baltic Sea, in plant tissue, in mink liver, and in threatened and endangered sea turtles along the southern coast of the United States, including the Kemp’s Ridley sea turtle, now the scarcest of loggerhead sea turtles. Levels of PFOA and PFOS measured in sea otters along California coast reported in 2006 were the highest yet found in sea mammals.

While these fluoropolymers and the smaller molecules into which they break down are being found in remote locations and far from where their products were used or made, they are also being detected in human bio monitoring studies all around the world. Testing by the 3M Company—until 2000, itself a major PFOA producer—found PFCs in 95 precent of the Americans it surveyed, while researchers from the Center for Disease Control found such compounds in 98 percent of the Americans it tested. These compounds have even been found in fetal cord blood of newborn babies. These babies, part of a study conducted in Baltimore, Maryland, were also predominately low-birth-weight babies, suggesting that there may be a connection between PFC exposure and prenatal development. Subsequent studies found similar incidence of low birth weights in babies born to mothers in Denmark carrying PFOA in their blood. As has been observed in some PBDE studies, PFC levels in children taken from biomonitoring studies appeared to be higher that those in adults in the same studies. Given that PFOA can last years and that reexposure is almost certain under current conditions, it’s not surprising that children have been found to carry proportionally higher loads of these chemicals than do adults.

There are so many of these compounds at large in the environment and PFCs last so long that PFOA has now been detected in deep ocean environments in the Labrador Sea, which occupies a critical location in global ocean circulation and could send contaminants into either European or North American Arctic, thus extending their routes of potential exposure to people and wildlife. Factor in subsistence global warming in the far north and it’s likely these contaminants’ potential impacts will be felt more directly than in more southerly locations….

In late 2008, PFOA and PFOS were found in sewage sludge used as fertilizer on agricultural fields used for cattle grazing near Decatur, Alabama, where there was fear that the meat itself might be contaminated. The chemicals are thought to have originated in wastewater from nearby chemical manufacturing plants. Similar cases of PFC contamination of waterways and sludge have been reported across the United States and elsewhere around the world.

Meanwhile, workers at plants that produce PFCs have routinely been testing positive for these compounds. Such discoveries date back to 1978. Testing of DuPont workers done throughout the 1980s and the 1990s found elevated blood levels of PFOA and employees at DuPont’s West Virginia plant were found—in company studies—also to have higher than normal rates of leukemia, heart problems, atherosclerosis, and aneurysms. Women at a 3M plant who’d worked with these chemicals reported instances of birth defects in their children in the early 1980s, and in 1997 traces of PFOA and PFOS were reported in donated blood supplies…

There turn out to be a number of nonstick cookware lines now being sold under the banner of “PFOA-free.”…. There are a number of these PTFE-based “PFOA-free” products now being made by DuPont and other PFC manufacturers.

How, I wondered, could a material be “PFOA-free” yet made with polytetrafluoroethylene (PTFR)? For an explanation, I spoke to Olga Nadeinko, a senior scientist with the Environmental Working Group. These compounds are big, Christmas tree-like polymers, she says, explaining that “the carbon backbone of the molecule is the trunk of the tree and the side chains with the fluorine atoms are the branches.” PFOA is also known as C8 because it has eight carbon atoms from which its fluorine branches stem. One of the new perfluorinated compounds being used as an alternative to PFOA or C8, she explains is a compound known as perfluorohexanoic acid (PFHxA)—or C6, so named for the six carbon atoms in the molecules that make up the backbone or tree trunk of this PFC.

“What happens,” Nadeinko continued, “is that eventually the branches break off the tree” and these branches that form six-, seven-, and eight-carbon-chain molecules are among the perfluorinated compounds now being found in children and adults. “In the human body, PFOA can last two to fourteen years—on average five—and honestly, you don’t want it there,” says Nadeinko. And these fluorine branches, she points out, can break off PFC trees with six carbons in their initial formulation just as they can from those with eight carbons.

Yet DuPont, one of the several companies offering products based on C6 chemistry, states that these Capstone products “are based on short chain molecules that cannot break down to PFOA in the environment.” The technology used to produce this new product, we’re told, requires “negligible PFOA and PFOA precursor content.” While the company maintains that these products are not made with PFOA, it also says that it “believes that no one can substantiate statements that fluorotelomer products [the basis of chemistry] are ‘PFOA Free’ or have ‘Zero PFOA’ even if test results are below the limit of detection.” This circular statement would seem to indicate that while these products are being marketed as “PFOA-free,” they actually may contain—and therefore be made with—these compounds….

Toxic effects observed have resulted not only from C8 but also from exposure to C6, and it appears that very small amounts—in micro molar concentrations—can produce adverse effects… Scientists can now locate the precise genetic receptors where many such chemical interactions occur and have learned that certain synthetic chemicals have molecular compositions and structures that enable them to interact with the site where a hormone would bind. This has been discovered for a number of common synthetic chemicals, including bisphenol A and the other chemicals Bruce Blumberg of UC Irvine called “obesogens,” for dioxins, and for perfluorinated compounds.” – Chasing Molecules: Poisonous Products, Human Health, and the Promise of Green Chemistry by Elizabeth Grossman


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