
The Teflon Toxin - sidko
https://firstlook.org/theintercept/2015/08/11/dupont-chemistry-deception/
======
smoyer
What struck me most about this article is how much rationalization occurred.
I'm amazed that a (presumably licensed) doctor can in one breath say they have
a moral responsibility to safeguard the public, their workers and the
environment, then in the next breath describe why the results of their own
study didn't apply.

But looking inward, I wonder if our industry doesn't do the same thing in many
cases - what about:

\- Eye strain caused by lack of contrast due to our favorite color palette.

\- Stress induced by unintelligible workflows.

\- Failure to protect a user's privacy.

\- Programs that induce RSI.

I realize this is a far cry from polluting the environment with toxins, but
shouldn't we at least think about these factors more often?

~~~
eevilspock
_> \- Failure to protect a user's privacy._

Advertising is our C8. It pollutes nearly every corner of the web with
deception and manipulation. It is the cause of the cancer called click-bait.
It is so profitable it has given rise to factories that pump out cheap junk
"content", overwhelming anything of merit on the web[1][2]. Then, to extract
even more from the devil in this Faustian bargain, we invade our very
customer's privacy, selling our soul twice over.

Most of us avert our eyes from this moral abdication because it funds our high
salaries and our get-rich-quick startup schemes[3]. Everyone seems happy with
their "free" non-stick pans and waterproof boots, so why spoil the party?

 _" It is difficult to get a man to understand something when his salary
depends upon his not understanding it.”_ – Upton Sinclair

If you agree with me, send me an email. I'm starting a project to whistle
blow, to raise awareness, to inspire change.

[1] Most people will miss this article about C8 because it doesn't stand a
chance against all the ad-supported garbage. The Intercept doesn't do click-
bait. Journalism, a cornerstone of democracy, is dying. This toxin analogy is
sadly too accurate.

[2]
[https://news.ycombinator.com/item?id=8585237](https://news.ycombinator.com/item?id=8585237)

[3]
[https://news.ycombinator.com/item?id=9961761](https://news.ycombinator.com/item?id=9961761)

-

 _> I realize this is a far cry from polluting the environment with toxins,
but shouldn't we at least think about these factors more often?_

Yes, demand a better work environment, but please don't compare "eye strain
caused by lack of contrast due to our favorite color palette" and "Stress
induced by unintelligible workflows" with an environmental toxin that never
existed until we created it, is now "in the blood of 99.7 percent of
Americans", causes cancer and birth defects, and may outlive humanity. Many
jobs have some stress on the body or mind or risks to life and limb (manual
labor, fire fighting). It is called "work" after all. The fire department is
not being evil. Dupont and 3M are. I hope you can see the difference.

~~~
qiqing
> Advertising is our C8.

This. Not to mention the malware that hitches rides on ad networks. Adblockers
being the new condoms and all that.

~~~
amag
Nah, we can always protect ourselves from ads or malware. Worst case we can go
completely offline or use an extremely locked down system.

C8 and similar compounds pollute the only inhabitable planet we have access
to, there's no escape from the pollution. The man-made C8 will remain in the
water and soil far longer than any human will be around, but before that it
will accumulate in our bodies and poison us. And C8 is just one such compound,
how many more are there?

------
lumberjack
And the settlement reached was around 0.0086 DuPont's yearly revenue to be
provided for education, water treatment facilities and medical expenses of the
class action members.

Is that really going to deter them from doing it again? Where is the real
penalty?

[http://www.hpcbd.com/Personal-Injury/DuPont-C8/C8-Class-
Acti...](http://www.hpcbd.com/Personal-Injury/DuPont-C8/C8-Class-Action-
Settlement.shtml)

~~~
gioele
> And the settlement reached was around 0.0086 DuPont's yearly revenue to be
> provided for education, water treatment facilities and medical expenses of
> the class action members.

> Is that really going to deter them from doing it again? Where is the real
> penalty?

Stefano Quintarelli, an Italian ISP-owner-turned-ITC-journalist has the nice
habit of converting those "huge" fines ("millions of euros!") into equivalent
fines for people with normal incomes. In this case he would write

"The equivalent fine for a person with an average income of € 30k per year
would had been € 258."

~~~
anentropic
this is great, I'd like to see this in every news article!

------
suprgeek
Take the number of vehicles in the field, (A), and multiply it by the probable
rate of failure, (B), then multiply the result by the average out-of- court
settlement, (C). A times B times C equals X...If X is less than the cost of a
recall, we don't do one.

What applies to the Car Industry (via Dialogue from Fight Club) applies to the
Chemical Industry in Spades. DuPont Knew (or strongly suspected) that C8 &
(Teflon) were causing Cancers, Birth Defects etc. But the cost was going to be
too high to move away so they all "kicked the can down the road".

Time to sock them with a multi-billion dollar verdict after some of these
people are locked up for long periods.

~~~
rhino369
The crazier thing is that for negligence torts (cars would be products
liability, which is different), that's exactly how the law works.

It's called the "Hand Formula" and you are only liable for negligence when PL
> B, where P is the probability of loss, L is the gravity of loss, and B is
the cost of avoiding the risk.

In practice though, it can be hard to argue that sort of thing. It's a little
academic.

~~~
greenshackle
Yes, of course. In a resource-constrained world, i.e. the world we live in,
spending more on prevention than the expected loss makes no sense.

Refusing to spend $10 to avoid a $5 expected loss is not negligence, it's
economic common sense.

(You should still be liable for the loss if _someone else_ is experiencing the
risk. You should be liable to compensate them fairly, but it's not
_negligence_ ).

In fact in a world with scarce risk prevention resources, PL = B is not even a
sufficient criteria to say you should spend to prevent the risk, because there
might be opportunities to prevent greater losses elsewhere; i.e. you should
not be investing to prevent PL = B type risks if there exists PL >>> B type
risks. (For a finance analogy, if you are capital-constrained, you don't want
to put your money in any investment with a positive ROI, you want to put you
money in investments that have _the highest_ ROI.)

In other words, spending $10 to prevent a $10 expected loss risk when there is
an opportunity to prevent a $100 expected loss risk for the same expenditure
makes no sense.

But since we're not smart enough to cooperate and globally allocate the total
risk-prevention budget to minimize losses, locally and in terms of personal
responsibility PL = B is a decent rule.

------
thezilch
I've never understood the gravity of Teflon pans. I can never seem to keep
them non-stick, whether it be because of using too high of heat or somehow
scratch the damn thing.

So, I got cast irons. It's trivial to keep them seasoned and thus non-stick,
and they can take the beating of very high heat -- searing meats -- and any
metal utensils or rough substances.

~~~
sanoli
How do you keep them seasoned? I tried a couple of times, but couldn't get it
right. Could you give me some tips?

~~~
blevs
Serious Eats has a very comprehensive guide [1]. The short version is rub
lightly with canola oil, put in hot oven for about 30 minutes. Take it out and
oil again. Repeat 3-5 times.

The only thing you need to avoid while cooking is overly acidic foods. If you
try to make a tomato sauce in it you will see the seasoning flake off. That's
not good, but is very easily fixed by repeating the above steps.

To clean it, scour the plan with kosher salt and a paper towel. Once clean,
coat lightly in canola oil.

[1]: [http://www.seriouseats.com/2010/06/how-to-buy-season-
clean-m...](http://www.seriouseats.com/2010/06/how-to-buy-season-clean-
maintain-cast-iron-pans.html)

~~~
spathi_fwiffo
For acidic things, buy an enameled cast iron. Those things are also great.
They need no seasoning, but are a bit more delicate (you don't want the enamel
to chip or crack).

~~~
simoncion
I grew up with traditional CI cookware. I know how to season it and how to
wash it.

The roommate recently purchased an enameled cast iron skillet. The use and
care guide was pretty poorly written. So, a couple of stupid questions on the
topic follow:

* The coating inside the pan is enamel, and doesn't need maintenance?

* One needs to not use metal utensils (or steel wool) in order to not damage the coating?

* One can wash the damn thing with soap and water without harming the coating?

Thanks in advance. :D

~~~
kaitai
As I understand it,

* no maintenance for inside

* don't use steel wool. With a stubborn stain I use a little baking soda, which some folks say is ok and others forbid. I use metal utensils despite being told not to. I use them gently and accept a few scratches; I try to avoid cutting things in the pan. I also wear contacts while swimming because I'm that kind of rebel. Meh.

* Soap + water = great :)

~~~
spathi_fwiffo
In addition, a lot of enamel will just stain after some time, which is normal;
This is why some of the vendors are just going with black enamel these days,
instead of the long-used white. I haven't tried baking soda to clear up the
stains on mine, I'll have to give it a shot.

Also, if the enamel cracks inside the cooking area of the pan, you may want to
throw out the pan; it may expose your food to contact with toxins used in
adhering the enamel.

~~~
maxerickson
I'd be more worried about eating chips of (sharp, hard) enamel than any toxins
- the firing process is not going to leave much other than the ceramic behind.

------
azinman2
Horrible. This is what's so scary about the free market and our current
chemical regulations of innocent until proved guilty.

People cover up, even the biggest most "professional" here (DuPont), and the
public gets decades of abuse.

Why is it that medication requires FDA approval with lots of animal/human
tests before you can sell it, but chemicals do not? Here the tests internally
done showed prove of issue year after year, and would have been a big red
flag.

~~~
13years
Free markets when supported by strong property rights can have strong
protections to prevent harm or pollution.

Non free markets, although regulated, don't necessarily perform better and can
even perform worse in this regard. The FDA is a great example of an agency
which often can be seen to work harder to protect the industry than the
individual. For example, look up the story of Vioxx. A drug which killed 50k
people, passed all FDA processes and when the manufacturer was caught hiding
data showing this would happen the product was not even removed from the
market as that would have opened the door for lawsuits against the
manufacturer.

~~~
knowaveragejoe
> Free markets when supported by strong property rights can have strong
> protections to prevent harm or pollution.

Can someone explain how this is supposed to work? I don't mean to sound
rude/biased but this sounds like one of those cases where the theory is sound
but when it meets with reality we get unpredictable(and sometimes disastrous)
results.

~~~
nickles
In Economics, the Coase Theorem[1] predicts close to this outcome, although it
speaks to efficient outcomes and not necessarily harm reducing outcomes. When
strong property rights exist (and it is feasible for all parties to
negotiate), then parties may reach an efficient allocation of resources
regardless of how the resources were initially allocated.

To use a typical example, imagine a train track runs through a farmer's land
and sparks from the train sets the farmer's wheat on fire, causing monetary
harm. If the train company owns the tracks, then the farmer should be willing
to pay to put spark guards along the tracks to protect his crop.
Alternatively, if the farmer owns the tracks, the train company should be
willing to pay for the damage to the crop to ensure that it can continue to
operate.

In practice, there may be costs associated with negotiations (e.g. lawyers),
it may be infeasible to negotiate between all parties (e.g. if there are many
farmers affected), or property rights are not sufficiently strong for one
party to bar another from producing negative externalities, all of which can
lead to failures of the theorem.

[1]
[https://en.wikipedia.org/wiki/Coase_theorem](https://en.wikipedia.org/wiki/Coase_theorem)

~~~
mikeash
The sparking train analogy fails because it supposes a single obvious entity
causing a large amount of damage to a single person.

To modify the analogy to fit the real-world situation, it would be more like
if there were a million train tracks going all over the place, and the sparks
from each train falls on millions of wheat fields, such that everyone lives in
a diffuse cloud of sparks, and no single fire can be blamed on any individual
train, and the harm from any single train is relatively small, even though the
collective effect is extremely damaging.

The Coase Theorem assumes that transaction costs are negligible. In a many-to-
many situation like real-world pollution, transaction costs necessarily become
prohibitively large, because you basically have a quadratic explosion of
connections between polluters and victims (many of whom are also polluters!).

~~~
nickles
Just wanted to point out that you restated what was said in the parent.

>In practice, there may be costs associated with negotiations (e.g. lawyers),
it may be infeasible to negotiate between all parties (e.g. if there are many
farmers affected), or property rights are not sufficiently strong for one
party to bar another from producing negative externalities, all of which can
lead to failures of the theorem.

~~~
mikeash
Yes, I was just trying to reinforce and generalize that, not try to argue
anything.

~~~
nickles
Gotcha

~~~
mikeash
And, sorry, I probably could have made that a little more clear! Like it or
not, the default on the internet is often to assume argument.

------
NhanH
On the topic of chemical, how do you know if something is dangerous -- in the
context of household item? Even with the MSDS and/or knowledge of the
compositions, layman doesn't really have any sense on how dangerous something
is (as it's all missing dosage). I'm a bit on the paranoid side (mostly
because I think my roommate/ housemate has always been too liberal with
spraying chemicals crap everywhere), and most of the time, even if I wanted to
I have no idea if I want to use something in my house.

~~~
notbingo
>even if I wanted to I have no idea if I want to use something in my house.

Everything in your house is toxic. Pick up anything with the ingredients on
the label and google a random one that has a funny name. Then read about it on
wikipedia and you can go further from there if you want and see the studies.
Chances are it is very toxic but it's used in small ammounts so you shouldn't
worry about it because the effects only show up after years and years of use.

Then look at the unlabeled stuff and food packaging. What's it made of? What
is it coloured with? What's in the glue that holds it together? What does the
paper have in it?

Checkout the uses for isothiazolinone and related compounds like
methylchloroisothiazolinone if you are curious about something that's in
practically everything.

~~~
NhanH
I think that's exactly the point I was trying to make. I know that whether
something is dangerous or not depends entirely on the concentration, and/or
the form of it (ie solid metal lead isn't too scary, any type of its compound
is). Unfortunately, I can't know the concentration(since packaging obviously
doesn't mention it), and I don't know what's the threshold I should be careful
about either.

------
greenyoda
More on C8, the chemical discussed in this article:
[https://en.wikipedia.org/wiki/Perfluorooctanoic_acid](https://en.wikipedia.org/wiki/Perfluorooctanoic_acid)

------
joeyspn
As the article says: this is another tobacco case, so they'll deny everything
even with fake/bought peer-reviewed studies. Just look how they treat their
own workers... My family already moved from non-stick cookware to stainless
steel. Consider doing the same in the mean time. As with the tobacco this will
be a marathon, and hopefully common sense will win.

------
1arity
Stick with cast iron ( or even aluminium ) chef's skillets. Season them with
oil or lard and build up that patina. No need for any teflon or manufacturing.
Plus the heft and look is way cooler. If you want to cook on plastic, do it in
a microwave. :)

------
gambiting
Question - I use these pans: [http://www.amazon.co.uk/Circulon-Infinite-Hard-
Anodised-Skil...](http://www.amazon.co.uk/Circulon-Infinite-Hard-Anodised-
Skillet/dp/B003ZYERM0/ref=sr_1_1?ie=UTF8&qid=1439371445&sr=8-1&keywords=circulon+infinite+30cm)

They are non-stick. But are they covered with Teflon? I honestly don't know.
They are oven safe up to 240C, I can put them in the dishwasher...they are
seriously the most durable pans I've ever used, unlike normal Tefal Teflon
covered pans which scratch easily. Does anyone know?

~~~
aembleton
These are Hard Anodized pans, and they don't use Teflon. I've got this set of
Circulon pans from Costco [1]; absolutely no problems and my friends have been
equally impressed with the non-stick properties. You can especially see it
when making something like scrambled eggs where the egg just doesn't stick.

[1]: [http://www.costco.com/Circulon%C2%AE-Premier-Professional-
Ha...](http://www.costco.com/Circulon%C2%AE-Premier-Professional-Hard-
Anodized-Nonstick-13-Piece-Cookware-Set.product.100104723.html)

~~~
increduloushulk
The pans you linked to do have a Teflon coating. Look at the fourth bullet
point under "Features," where it says it uses DuPont Autograph. Autograph is a
product within the Teflon line.

------
acd
You can make superhydrophobic surfaces with laser etching that affects the
nano structure of the metal. Thus if you take a strong metal and laser etch it
there is no need for potentially dangerous Teflon coating.

[https://www.rochester.edu/newscenter/superhydrophobic-
metals...](https://www.rochester.edu/newscenter/superhydrophobic-
metals-85592/)

~~~
LukeB_UK
Except doing that on a large scale would be super expensive.

~~~
dekhn
Why? Typically, whenever you do something in the large scale, you can amortize
the capital cost of the equipment to zero (economy of scale) and if the
product is popular, inventors will come up with cheaper ways to run the
manufacturing facility.

That said, lasers do use lots of power so it will probably be marginally more
expensive.

~~~
lfowles
It's not just capital cost for equipment that needs to be considered at this
stage, but also the research needed to make suitable equipment for large scale
production. Per the article, a 1"x1" section of metal takes an hour.

Maybe some day, but then "there is no need for potentially dangerous Teflon
coating in 10-15 years" would be more appropriate.

------
kragen
I guessed this might be about PFOA when I saw the headline!
[https://en.wikipedia.org/wiki/Perfluorooctanoic_acid](https://en.wikipedia.org/wiki/Perfluorooctanoic_acid)
has the whole story, minus the anecdotes. Apparently a few parts per billion
of PFOA in your drinking water is enough to detectably raise your risk of some
cancers. Most environmental regulatory agencies propose 0.5 to 1 ppb as a safe
limit for _drinking water_ , while 4–5 ppb _blood serum levels_ of PFOA are
currently common among "unexposed Germans".

I was pleased to see that they aren't hyping the risk of cooking on Teflon.

------
codexjourneys
Teflon has been known to be toxic for years. I'm not sure why "default trust"
is a good position when dealing with companies like DuPont and Monsanto that
have been caught lying to the public before. "Default suspicion" seems like
the more cautious and logical approach here.

It's been more than a decade since I cooked with Teflon. I use glass,
stainless steel, cast iron, or ceramic/enamel (love that old original
Corningware from eBay!).

Much like eating real food, it's not hard to switch and the result tastes
better.

~~~
scott_karana
> and the result tastes better

I don't doubt all your other points, but why did you include this one?

Are you claiming that teflon-coated surfaces somehow add a taste, or
demonstrably change the texture of the food cooked on it?

~~~
codexjourneys
I've tried both and like the result from stainless steel and Corningware
better. Granted, I was using older-style pans made a decade or so ago. YMMV,
though the Teflon is not healthy for high-heat cooking. I avoid it, why
bother?

------
avirambm
I highly recommend watching The Human Experiment documentary about chemicals,
toxins and the chemical industry strong lobby. It's available on Netflix.

------
egypturnash
> A DuPont lawyer referred to C8 as “the material 3M sells us that we poop to
> the river and into drinking water along the Ohio River.”

Yet another lovely thing I'm sure I ingested when I grew up drinking tap water
in New Orleans what with the Ohio being the biggest tributary to the
Mississippi.

------
jjw1414
It may seem nit-picky, but the word "toxin" refers to a harmful substance
produced by a living organism (e.g. snake venom). For a synthesized or
manufactured chemical that is harmful, "toxicant" or simply toxic chemical is
the correct term.

------
stretchwithme
All that teflon is going somewhere when it falls off the pan. Its going in the
food and into your body. I'd rather not run that experiment.

So many years ago I started using a glass frying pan.

~~~
rcthompson
Teflon itself is pretty much inert. That's the whole point - nothing reacts
with it, nothing sticks to it. The worry is about the chemicals used to
manufacture it.

~~~
azinman2
Heat your Teflon pans with nothing in it and it'll kill a canary. Hardly
inert.

~~~
ars
Heat it with oil and it will kill the canary at a lower temperature than
teflon.

Ergo oil is toxic.

You are using bad logic and bad science.

~~~
azinman2
Where are you getting that info?

~~~
ars
From the FDA. Before they approved teflon for use in cookware they tested it
vs oil.

Oil was found to be toxic at a lower temperature than teflon, making teflon
safer than oil for high heat cooking.

Obviously when I say "oil is toxic" I'm being sarcastic.

~~~
gruez
Not that I'm doubting you, but can I have the source for your claim? I want to
present it to my chemophobic friends.

~~~
ars
[http://www.tandfonline.com/doi/abs/10.1080/0002889738506828](http://www.tandfonline.com/doi/abs/10.1080/0002889738506828)

Exposure of Japanese Quail and Parakeets to the Pyrolysis Products of Fry Pans
Coated with Teflon® and Common Cooking Oils

Lethal temperature:

butter: 260°C/500°F

Teflon: 330°C/626°F

plastic handle: 370°C/698°F

~~~
azinman2
Fascinating. Luckily butter almost never gets to those temperatures. We're
obviously different animals, and it seems that birds can eat butter, so I
wonder what it is about oils specifically that kills them. Likely the
mechanism will be different from PTFE and PFOA and maybe incompatible with
humans who also suffer from large-scale inhalation (see article). We don't
know much about long term PTFE/PFOA inhalation in small quantities.

So it seems to be that cast iron itself, heated, doesn't cause the bird to
die. Cast iron + butter kills the bird, but so does teflon + butter. So in
butter-less dry pan to dry pan scenarios, cast iron is non-toxic yet teflon is
toxic.

As you can see here [1] if you leave your pan on the stove heated it can hit
these toxic temperatures within minutes. So the exposure to the gas isn't
hypothetical. Dry pan toxicity is a real concern which is unique to Teflon.

Then there's digesting it since it will slowly wear off into your food. We
don't have science specifically looking at long-term slow exposure to
PTFE/PFOA. So you're taking your chances... but we do know that PFOA is much
less inert than PFTE when digested.

Non-stick pans won't last as long as cast iron or stainless steel, and cast
iron can perform like non-stick while also adding flavor and necessary iron.
Oh and cast iron can be often as cheap or cheaper than non-stick (except for
the super crazy low end, but talk about most likely to be toxic...), and most
certainly is cheaper in the long run (I'll have my great-grandmother's pan for
the rest of my life which I do 90% of my cooking in... try that with your
teflon).

So if you don't need non-stick pans, so why voluntarily expose yourself to the
risk?

[1]
[http://buffalobirdnerd.com/clients/8963/documents/Teflon.pdf](http://buffalobirdnerd.com/clients/8963/documents/Teflon.pdf)

~~~
ars
> so I wonder what it is about oils specifically that kills them

I think it's just the smoke, nothing special about oil or teflon. I wonder if
smokers have a problem with bird health?

Cast iron has oil on it when seasoned. I suspect the study used "clean" cast
iron.

------
nnq
Wait... _so nobody even got life-in-prison for this shit??!!_

My gut reaction is the we should _seriously consider_ resurrecting worse-than-
death-penalty sanctions for the executives and scientists involved. I'd
propose something like this for the fully-informed company executives and free
acting scientists:
[https://en.wikipedia.org/wiki/Nine_familial_exterminations](https://en.wikipedia.org/wiki/Nine_familial_exterminations)

------
vladsanchez
This was one of the best investigative reports I've read. Thanks for sharing
this cover-up.

------
Nano2rad
Teflon is an insulator compare to iron. Thermal conductivity W/(m K) Teflon
0.25, Iron 80[1]. So Teflon coating reduces cooking, heating efficiency.
[1]engineeringtoolbox.com

------
im3w1l
Tl;dr? How badly am I destroying my health by using a Teflon pan?

~~~
Htsthbjig
Now Teflon has not C8 on it as it is manufactured.

You will create dangerous compounds though if your pan goes over high
temperature. This could happen if for example there is no oil in the pan. I
have seen housewives and cookers heat the Teflon pan without oil for
evaporating the water. Big no no with Teflon.

I have seen metal scrappers burning teflon pans to use the pan for something
else and painting it!(with teflon you can't paint it)

The big problems with exotic chemicals is that people could do extremely
stupid stuff without them realizing they had done anything wrong.

It is not like red alarms will start ringing or something. It is just silent,
and two years later you will have cancer.

~~~
im3w1l
>I have seen housewives and cookers heat the Teflon pan without oil for
evaporating the water. Big no no with Teflon.

Oops... I regularly do this. Same question as previously.

~~~
Htsthbjig
I do this on cast iron. Never on Teflon.

You can use an oven thermocouple to measure the temp of your pan as you heat
it without oil. If you do it once,and compare with the temps that are
dangerous(you could see it on Internet) you will never do it again, as you
will realize how fast temp goes up and how easy is to manufacture C8 with your
pan.

Water acts as a limit of temperature, when it is wet it can't go higher than
100 Celsius(locally, it can in the parts of the pan that are dry). But once
all water is gone, it goes hot incredibly fast. Oil does the same but with
higher temperature than water, with way higher boiling pressure.

If someone does this mistake in one of my Teflon pans, I just throw it away. I
never trust pans that are not mine.

Obviously, when you see smoke in the oil it is not good either.

By the way most of my pans are ceramic or cast iron.

~~~
ars
> Obviously, when you see smoke in the oil it is not good either.

Exactly. The important takeaway here is that teflon becomes toxic only _after_
the smoke point of the oil. i.e. oil is more toxic at high temperature.

So putting in the oil doesn't protect you from toxic fumes since you get those
from the oil, but rather it gives a visible signal (smoke), that you could
quickly turn off the heat because you are about to damage your pan. But as far
as toxic fumes go it's too late - you already had those from the oil.

