A Silent Killer of Birds In Our Care: Heat Generated PTFE Fumes
Without warning or visible vapor in homes, zoos, and wildlife rehabilitation facilities
A Rachel Carson Council Alert
From Coal Mines to Kitchens
On Saturday, November 12, 2000, Ron, the owner of eight pet birds, started the self-cleaning oven cycle in preparation for Thanksgiving dinner. His windows were open, in compliance with the oven directions, Two hours later, his son noticed that one of the birds was having trouble standing. (all birds were located in a separate room off the kitchen). Four of the birds died quickly in Ron's hands before anything could be done. Opening more windows saved the other birds. Microscopic Lung findings were consistent with the inhalation of toxic chemical fumes. No warnings about release of a toxic gas were found in the oven's directions, but the source of the fumes was the oven's nonstick coating based on PTFE.* Confirmed by a necropsy examination, four pet bird fatalities resulted from normal operation of the cleaning cycle of this PTFE-coated oven. (Ramelmeier & Davidson)
With their sensitive respiratory systems, birds have been used to protect us by detecting poison gas since early in the industrial age — the legendary canaries in the coal mines (and the trenches of World War I) — frequently with lethal outcomes for the birds themselves. Now it is our turn to protect them from a modern hazard.
Those who care for birds need to know about Polytetrafluoroethylene (PTFE) poisoning — the most commonly reported inhalant toxicity in avians. (LaBonde) Fatalities in birds have cleaning ovens, coated cookware, coated baking sheets, newly developed coated light bulbs, coated heat lamps, etc. (See "Could This Happen to Birds In Your Care?" and "PTFE Scientific & Trade Names.") In protecting birds, we may be protecting ourselves as well. Although much less vulnerable, people also have been poisoned by PTFE fumes. (Lee)
The Danger Is Real
Information on avian PTFE toxicity has been available for more than a quarter century. However, not everyone living or working with birds is either aware of heat-generated fife toxicity or of which commonly used products could be potential sources of the fumes. Sadly, many household items capable of generating PTFE fumes (see "Sources of PTFE") do not carry sufficient identifying information, and most have virtually no warnings about the hazards they represent for birds, (Forbes & Jones) Yet, apparently, in 1997, a spokesperson from the major PTFE manufacturer acknowledged that fumes from overheated nonstick coatings could be deadly to birds, (Anon., European Chemical News)
Toxicity in Birds
When PTFE-coated surfaces are heated above 260°C (400°F), toxic products are released that can kill a bird in minutes. (LaBonde, Forbes & Jones) In most high exposure cases, onset of death occurs rapidly with no chance for successful medical intervention. In cases of lower exposure, eye blinking, panting, and anxiety may be seen. Birds showing these signs will also perish, if not moved to fresh air immediately. Symptoms can be gasping, staying on cage floor, collapsing, and death.
"Extreme levels of fumes may lead to acute deaths of all birds in the air space immediately. In contrast, low levels can lead to intermittent deaths of birds within a group over a period of weeks or months? (Forbes & Jones) A necropsy can help confirm the cause of death as PTFE fumes.
Toxicity in Humans
People! affected by heated PTFE may show a well-described illness called Polymer-fume Fever, a flu-like disease with temporary symptoms. Rarely, it may lead to breathing difficulties requiring emergency treatment. (Lee)
PTFE is used in a variety of products including cookware because it is not easily broken down. At or above 260°C it forms various byproducts including TEA (trifluoroacetate), a persistent chemical thought to have the potential for environmental problems. (Ellis et al.) The environmental impact of PTFE use has not been well investigated. Scientists have called for more research on impacts of TEA and other PTFE byproducts. (Ellis et al.)
Could This Happen to Birds In Your Care?
In addition to the tragic outcome suffered by Ron's pet birds following use of a self-cleaning oven, other PTFE-coated products have been linked to avian deaths.
A PTFE-Coated Baking Sheet Hazard
PTFE-coated baking sheets can be dangerous when they come close to a heat source. In one incident, the last bird of a group of four died, "...within 15 minutes of the owner overheating the sides of a baking sheet." (Forbes & Jones)
A Plea for Warnings
"I ... lost my miniature macaw two weeks ago. He died from the toxic fumes [given off] by an overheated ...pot. An irreplaceable loss. Please spread the news — not to cook with nonstick cookware.. .so deadly to birds!" (Internet communication)
A PTFE Hazard During Rehabilitation
Eight birds of prey died over a period of three months in a facility that was using PTFE-coated heat lamps to warm them overnight. The lamps appeared to function safely for one year, after which time with continued use at their normal working temperature... poisonings occurred [due to PTFE]? (Forbes & Jones)
Poultry at Risk from Treated Lights
Fifty-two percent of the chicks in a poultry research facility died within 72 hours after replacement of 48 heat lamp bulbs with PTFE- coated ones. Microscopic lung changes were consistent with PTFE poisoning. (Boucher)
PTFE Scientific & Trade Names
PTFE is a type of plastic or synthetic polymer known as polytetrafluoroethylene or tetrafluoroethylene resin. PIFE coatings are sold under the trade names Teflon, Silverstone, Fluoron, Supra, Excalibar, Greblon, Xylon, and others. PTFE may be found in:
- self-cleaning ovens
- crock pots
- nonstick pans and utensils
- shatterproof light bulbs
- ironing board covers
- stove top drip pans
- coffee makers
- portable heaters
- waffle makers
- hot-air popcorn makers
- tortilla grills
- reverse cycle air conditioner heating elements
- items, such as a wood perch, baked in a PTFE-coated environment for sterilization
What Can You Do To Protect Birds from PTFE Poisoning?
- At the first sign of illness, remove the birds to fresh air and Call a veterinarian.
- Check your household products for PTFE-coated surfaces. If your oven is self-cleaning, check to see if it is lined with PTFE. Contact the manufacturer to be sure.
- Do not locate birds in or near your kitchen.
- If you must use PTFE-coated cooking products, monitor them carefully to avoid overheating, provide good ventilation (turn off central air and open your windows), and dispose of cookware when it becomes damaged.
- Do not use PTFE-coated heat lamps around birds for any reason; it just isn't worth the risk. (Darrel Styles, DVM)
- Spread the word to bird owners about PTFE's hazards!
- Join RCC in requesting that all PTFE-containing products include animal health information, such as the following:
|WARNING! This product contains PTFE, known to release toxic fumes potentially fatal to birds when the product is overheated. Keep birds away from this product.
Anonymous. European Chemical News, v.68, #1779, 1997, p. 26.
Boucher, M., et al "Polytetrafluoroethylene gas intoxication in broiler chickens." ,4vian Diseases, vol.44, 2000, p. 449-53.
Ellis, et al. "Thermolysis of fluoropolymers as a potential source of halogenated organic acids in the environment." Nature, vol. 412, July 19, 2001.
Forbes, NA. and 0. Jones. PTFE toxicity in birds (letter). Vet Record, vol. 140, #19, May 10, 1997, p.512.
LaBonde, J. "Pet Avian Toxicology" in 1988 Proceedings Association of Avian Veterinarians, pp. 159-173.
Lee, C.H., et a]. "Fatal pulmonary oederna after inhalation of fumes from polytetrafluoroethylene (PIFE)." Eur Respirj, vol. 10, 1997, pp.1408-1411.
Ramelmeier, .L. & J.P. Davidson. "Fatalities in four psittacines, as a result of normal operation of the cleaning cycle in a polytetrafluoroethylene (PTFE) coated oven." Pesticides, People and Nature (in press).
Styles, Darrel D~M. "Teflon poisoning: the silent killer." Old World Aviaries (internet source).
Historical Note: The Rachel Carson Connection
References have been found to PTFE's toxicity among Rachel Carson's collected papers, so she very likely was aware of its potential hazard. During her lifetime, the only reports of PTFE toxicity (or Polymer Fume Fever as it was called) were from industrial sources and only in humans. In helping to prevent PTFE-related suffering and death, we at RCC endeavor to continue Rachel Carson's work.
Rachel Carson Council (RCC), an association for the integrity of the environment, is one of Rachel Carson's enduring legacies. In its publications (now more than 150), RCC unites accurate scientific information with a sense of wonder and respect for nature and a concern for the health of all living beings, reflecting major themes in Rachel Carson's own work. RCC can be reached by e-mail at RCCouncil@aol.com. Our web site is: http://members.aol.com/rccouncil/ourpage/
RCC Alert: February 2002
By Drs. Jennifer Ramelmeier and Diana Post Thanks to Ruth Hannessian, Dr. Greg Harrison, Dr. Stuart Porter, and Donna K. Savage for valuable assistance.