[JSmith]

Your right special powers, perhaps if you’re a doctor you’d like to have a look at the relevance of this??

(If this is you Gem Bob – I knew it was!!!!)


Some fume will be generated even at the temperatures
reached during the normal hot processing of fluoropolymers such as Teflon
and it is necessary to assume that the resulting fume
will present a potential health hazard. It is essential that
adequate ventilation is provided to prevent exposure in the
workplace. The consequence of overexposure
to the fumes from fluoropolymers decomposing
under these conditions is “Polymer Fume Fever” also
known as “The Shakes”.This is a temporary, influenza like
illness with fever, chills and sometimes a cough.
The illness is also associated with exposure to the decomposition
products produced by smoking tobacco products,
such as cigarettes, which have become contaminated by
fluoropolymer resins, even by trace quantities. It is essential
that smoking and tobacco products be banned in work
areas where fluoropolymer resins are handled.
The three main types of product formed in the decomposition
of fluoropolymers are fluoroalkenes, oxidation products
and low molecular weight fluoropolymer particulates.
In the case of PTFE there are many studies in the published
literature and these report a wide variety of results
for the reasons outlined above.The general pattern, however,
is that the monomer, tetrafluoroethylene, is the principal
gaseous product at the gel point of the polymer
(330°C).As the temperature increases to around 450°C, in
the presence of air, carbonyl fluoride and hydrogen fluoride
become the main products. Also some carbon
monoxide may be formed. Carbonyl fluoride hydrolyses
rapidly in the presence of moist air to hydrogen fluoride
and carbon dioxide. Small amounts of hexafluoropropylene
may also be found at these temperatures.The highly
toxic perfluoroisobutylene has been detected as a minor
product at temperatures above 475°C.When the temperature
reaches about 800°C tetrafluoromethane begins to
form.
There is a similar decomposition pattern for other fluoropolymers.
Decomposition products tend to form at
lower temperatures to a degree which depends on the type
and amount of comonomer in the fluoropolymer. Health
hazards of these products are as follows:
Hydrogen fluoride:The odour threshold of hydrogen fluoride
is significantly less than the occupational exposure
limits which are typically of the order of 1ppm. Inhalation
of hydrogen fluoride at higher concentration will give rise
to symptoms of choking, coughing and severe eye, nose
and throat irritation. In severe cases, and possibly following
a symptomless period, fever, chills, difficulty in breathing,
cyanosis, and pulmonary oedema may develop which may
lead to death. Acute overexposure to hydrogen fluoride
can result in injury to the liver and kidneys.
Carbonyl fluoride: Effects following inhalation, ingestion,
or skin or eye contact with carbonyl fluoride may initially
include: skin irritation with discomfort or rash; eye
corrosion with corneal or conjunctival ulceration; irritation of the upper respiratory passages; or temporary lung
irritation effects with cough, discomfort, difficulty in
breathing, or shortness of breath. Respiratory symptoms
may be delayed for several hours.
Carbon monoxide: An odourless gas which reduces the
oxygen carrying capacity of the blood, resulting in a
decreased capacity for exertion, increased load on the heart
and with severe exposure, unconsciousness and death.
PFIB (perfluoroisobutylene): PFIB is highly toxic by acute
inhalation, and exposure to concentrations above 1ppm
for any significant period can be fatal.
TFE (tetrafluoroethylene): Tetrafluoroethylene is a colourless,
odourless and flammable gas that is very poorly
soluble in water. Tetrafluoroethylene has a very low
toxicity after acute exposure and has no cardiac sensitisation
potential and it has no genotoxic potential in vitro
and in vivo.When administered for a long period, it may
cause toxic effect primarily to the kidney. In a 2-year bioassay
in rats and mice, tetrafluoroethylene caused various
kinds of tumours in the kidney, liver and the haematopoietic
system.These effects were seen at high dosages. Studies
comparing human and animals metabolism suggested that
the risk to human to developing some of the tumours is
low for humans.The current TLV/TWA value is 2 ppm
(ACGIH 2001). Further studies to understand the whole
mechanism are still under evaluation. A multicentre epidemiology
study involving the major producers of TFE is
ongoing.
HFP (hexafluoropropylene): Hexafluoropropylene is a
colourless, odourless gas that is very poorly soluble in
water. Hexafluoropropylene has a low toxicity after acute
exposure. The genotoxicity of the compound was considered
overall negative.When administered for a long period
it may cause toxic effects primarily to the kidney. No
official TLV/TWA has been established by ACGIH. The
producers have set a provisional internal OEL value of
0,5 ppm.