Teflon - A Sticky Issue

DuPont has been conducting an advertising campaign in major newspapers in various parts of the world, including Australia, asserting its product Teflon® is safe. In its advertisements DuPont is at pains to distance Teflon from the PFOA (perfluorooctanoic acid), which is used in the manufacture of Teflon to give Teflon-coated cookware its non-stick property.

The US Environmental Protection Agency (EPA) has been investigating PFOA because it "is very persistent in the environment, was being found at very low levels both in the environment and in the blood of the general U.S. population, and caused developmental and other adverse effects in laboratory animals."The main message of the 'Teflon is safe' campaign is that Teflon is not PFOA. But is Teflon safe? The problem is that when cookware is used at very high temperatures the Teflon coating decomposes and gives off toxic gases. As early as 1991 researchers reported in the journal Chemical Research in Toxicology that PTFE (polytetrafluoroethylene - the chemical name for Teflon) has "long been known to evolve toxic products when heated above normal service temperatures."It is the "normal service temperatures" that is the key here. DuPont's advertisements claim that PFOA is not detected in Teflon coating when used "under normal cooking conditions". But what does DuPont mean by normal cooking conditions? DuPont admits on its teflon.com website that "Significant decomposition of the coating" occurs "when temperatures exceed about 660°F (349°C)-well above the smoke point for cooking oil, fats or butter". But it claims that "it is unlikely that decomposition temperatures for non-stick cookware would be reached without burning food to an inedible state."

The website goes on to say "However, these high temperatures can be reached if dry or empty cookware is neglected on a hot burner or in an oven-a safety hazard that should be avoided with all cookware." A safety hazard not mentioned in the 'Teflon non-stick coating is safe' advertisement.

A 2003 study conducted by the respected Washington DC-based research group, the Environmental Working Group, found that an aluminium fry pan coated with Teflon took only five minutes to heat from room temperature to 721°F (383°C) when the element was on high.The DuPont advertisement also refers to the Australian regulator, NICNAS (National Industrial Chemicals Notification Assessment Scheme), as endorsing the safety of Teflon. Dr Roshini Jayewardene, Leader Regulatory Strategy & Reform at NICNAS says that "based on the information available, there is absolutely no risk to the consumer when using non-stick cookware under normal cooking conditions". She claims that if you heat a frypan above 350°C you would "incinerate" the food.

But at temperatures of around 260°C, which is just below the smoke point for safflower oil, Teflon gives off fumes according to a warning on an earlier version of DuPont's Teflon website. It said that Teflon can "emit fumes harmful to birds, if cookware is accidentally heated to high temperatures, exceeding approximately 500°F (260°C) - well above the temperatures needed for frying or baking".Another problem is that drip pans can get to temperatures high enough to emit fumes even under normal cooking conditions. DuPont noted that Teflon-coated "drip pans should be avoided because even in normal use they reach extremely high temperatures and can emit fumes that are hazardous to birds." DuPont maintains Teflon is safe for humans whilst warning people to "never keep your pet bird in the kitchen".

The DuPont advertisements boast that "DuPont has been praised by the US Environmental Protection Agency for our 'leadership' in reducing PFOA emissions". Yet in December last year that same agency levied the largest environmental administrative penalty in its history against DuPont for failing to "report information to EPA about substantial risk of injury to human health or the environment that DuPont obtained about PFOA from as early as 1981 and as recently as 2004."PFOA is now found in the bodies of people all over the world. Given that the manufacture of Teflon is a major contributor to PFOA in the environment, can DuPont really assert, without qualification, that Teflon is safe? Wouldn't it be more responsible to say that Teflon is not safe to manufacture but they believe it is safe to use provided people don't heat their cookware to temperatures above 250°C and never heat an empty Teflon-coated container?

Sharon Beder is author of "Suiting Themselves: How Corporations Drive the Global Agenda" and "Environmental Principles and Policies" (UNSW Press, Sydney) forthcoming.