Risky business: on copper pots, Teflon pans and exploding ovens

by Forager on June 4, 2011

On my Paddock to Plate degustation post, one reader, Alex, left me an interesting, albeit totally unrelated comment to the post topic:

“…Teflon contains a chemical called per-flouro-octanoid-acid also known as PFOA, which can cause cancer. If you over heat teflon coated pans, to 260 degrees Celsius, you get the risk of releasing that chemical…and this is a risk not worth taking.

So although teflon coated pans are easier to use, they imply high risks on our health…so it is advised that they be used properly. The alternative to these pans is using copper pans, as they conduct heat quickly…”

This reminded me that I’d read something on this topic before in my travels and though I had a backlog of posts to write, it inexplicably sent me off on a little sideways research project. I’ve always been a superb procrastinator.

I started by reading about PFOA or per-fluoro-octanoid-acid in the very reputable research source Wikipedia (*ahem*) which claims PFOA seems to be riddled everywhere in our environment, a throwback to the practices in the industrial revolution days but importantly initial studies seem to conclude that apparently PFOA exposure from cookware is insignificant unless used at “temperatures well above those encountered in cooking”.

Even as my reader commented, PFOA becomes a risk above 260 degrees Celsius. Do those figures mean anything to you without a frame of reference? Personally, I’m hardly ever likely to heat a Teflon pan above 260 degrees Celsius via my day to day cooking practices as I usually use my Teflon wok for quick stir frying and avoid deep frying if I can help it as (both the Co-pilot and I are semi fat-phobes). Using your pan for deep frying can catapult it to that high temperature range but the ultimate temperature you achieve will depend on the smoking point of the oil you use. Animal fat has a low smoking point of 180 – 200 degrees C; olive oil has a smoking point of 190 deg C; peanut and corn are 231 and 236 deg C respectively and sunflower is 246 degrees C. But if you’re heating oil to the smoking point, it will be “smoking” as the term suggests, and you have more immediate concerns than Teflon flu. Generally frying should occur at temperatures of about 190 degrees, far lower than that pivotal 260 degrees C danger point. Hell, even my oven only goes to 260 degrees Celsius, and the last time I turned that to 260 degrees Celsius, it exploded and showered me in glass! True story.

Don’t get me wrong, I’m not trying to defend any commercial interests and I haven’t bought Teflon shares, I’m just trying to cast a critical eye over the information and weigh up the arguments. There’s no doubt that there is some pretty concerning information out there on Teflon and PFOA and “Teflon flu” sounds rather undesirable (deadly if you’re of the avian persuasion), but currently even the EPA doesn’t believe there is a need for consumers to stop using Teflon products. There is a wealth of information out there on the topic – but most of it in the form of articles and blogs quoting and paraphrasing one another – there is very little scientific evidence at the heart of this – whether for or against. My own efforts to find some scientific evidence supporting either way in scientific databases have largely turned up empty handed. The most conclusive and recent evidence I found was published last year in 2010 and showed ironically that there was a lack of epidemiological evidence to draw any firm conclusions on the role(s) of PFOA in disease.

Either way, there’s no harm in avoiding overheating your Teflon pan – not a good idea as you might end up with Teflon flu or in the very least, it might burn whatever you’re trying to cook and set off the smoke alarm.

So what else if not Teflon? Is copper our saviour then? Perhaps not so.

According to one of my most thumbed books on my bedside table, Professor Robert L Wolke’s book “What Einstein Told His Cook“, a good pan generally should be made from a high conductivity metal that transmits heat to the food quickly, efficiently and responds to changes in stovetop burner settings quickly too – so when you turn the heat down, the pan cools down and vice versa.

It is true that copper pans are indeed fantastic heat conductors, in fact only a pure silver pan is a better conductor (if you can afford to cook with pure silverware that is), but he states too much copper in our diet is “unhealthful” (studies show excessive copper is thought to correlate with a number of mental and neurological illnesses including schizophrenia and Alzheimer’s Disease). So like those Teflon coated pans, copper pans are also lined. Older copper pans used to be lined with tin, which melts at roughly 230 degrees C – clearly, undesirable to be supplementing your diet with tin. Modern copper pans are actually lined with a thin layer of nickel or stainless steel and because they’re so hard to manufacture will cost an arm, leg and kidney. But those lauded vintage copper pans are probably equally if not more harmful to our health than Teflon and at the lower melting point of tin, the health risks are more likely to be encountered in everyday cooking. A shame if this is indeed true because they are so. very. lust-worthy.

So, modern copper pans seem to be the bees knees and if you are the proud owner of some copper pans you’re probably pretty pleased about them. But, are they really what you paid for?

When the Co-pilot and I were shopping for our new kitchen when we moved in to our current home, we looked longingly at the expensive copper pans on display at high end shopping centres. But, much to our dismay, we found many of those mainstream and the more “affordable” copper pans were merely copper plating on a stainless steel core. This is essentially the exact reverse of what you want in a good copper pan. Whilst the copper plating will conduct the heat effectively, the core material – often aluminium or stainless steel is a poor conductor of heat. Whereas solid copper conducts heat 91% as effectively as a silver pan, aluminium is only 55% as effective and stainless steel a paltry 4% as effective as silver. So if you bought one of these, I’m sorry, but the copper coating on these pans is purely cosmetic.

But on the subject of dangerous cookware, more immediately dangerous than both Teflon pans and copper pots is arguably an exploding oven. The explosion occurred unexpectedly one weekend when we were making our roasted pork with fennel seed rub. As per my sea urchin foraging post, when I faced off with the snake, I was once again dismayed to discover my reactions in the event of imminent danger. We preheated our oven and whilst prepping the rest of the roast, we both heard the muffled bang, both felt the light shower of glass fragments like a puff of air on our legs and both stared down in bewilderment, stunned and thoroughly immobilised. The Co-pilot regained his survival senses first, figured out what had happened and shooed the still frozen me out of the kitchen (I have come to accept that my fight or flight responses must have been left out of my genetic code as I am truly pathetic in dangerous situations) whilst he valiantly turned his face away, then in one swift motion, opened the oven door to allow it to cool down and scooted out of the kitchen.

Our new oven window exploded during pre-heating, showering our legs in glass fragments

Our new oven window exploded during pre-heating, showering our legs in glass fragments

Only when we were satisfied that the oven had cooled enough did we venture back in and peer into the inky mouth of our angry oven. The oven window had indeed shattered and impressively so. The small fragments of glass that had blasted against our legs thankfully did no harm as we both had jeans on, and they were scattered over the floor like discarded jewels. The glass in the window had stayed intact in one beautifully fractured tortured piece. We could see the offending epicentre of the damage from whence the glass fracture had rippled out.

Oven window fragments, glass, It's the way it shatters that matters

It's the way it shatters that matters

Concerns about food overcame concerns about safety and not keen to waste our intentions of roasted pork, we hightailed our operation to the Co-pilot’s parents’ house to continue the cooking. This is a perennial family favourite recipe of ours and one I’ve posted before haphazardly in the early days of this blog, but given the number of times both I and family and friends have referred to it, here’s a more user friendly version.

Fennel-crusted pork roast with apple and leek puree

Ingredients (serves 6):

  • 1.5 kg pork shoulder or loin (skin on for crackling)
  • 4 tbsp fennel seeds
  • 2 tbsp whole white peppercorns
  • 1 tbsp grated lemon rind
  • 2 tbsp olive oil
  • 1 tsp salt
  • 4 apples, peeled and chopped
  • 2 leeks, white section, chopped
  • 100g butter or ghee
  • 1L chicken stock
  • vegetables for roasting (optional)
  • salt and pepper


  1. Preheat oven to 240 degrees C and pat dry pork.
  2. Grind the fennel seeds, salt and peppercorns together in a mortar and pestle (or spice grinder) to release their aroma. Add grated lemon rind and olive oil.
  3. Score  the skin in a criss cross hatch pattern using a sharp knife. Rub spice mix onto the pork and work into the skin well. Place onto a rack or a greased baking tray. Roast at 240 degrees for 15 minutes to start the crackling off, then turn down to 200 degrees and roast for a further 80 minutes (account for about 25 minutes per 0.5kg of pork). If desired, throw in peeled potatoes, pumpkins, onions and garlic for roasting.
  4. Meanwhile prepare the puree – gently sweat the leeks on low heat until soft, then add apples, chicken stock, salt and pepper and simmer until apples are soft and stock has reduced by half. Use a stick blender to blend to a smooth consistency.
  5. Allow the pork to stand for 5 minutes before serving with the warm apple and leek puree.
The pork is seasoned with the fennel seed rub, then the crackling is scored and prepped in a hot oven, before settling in for the long roast.

The pork is seasoned with the fennel seed rub, then the crackling is scored and prepped in a hot oven, before settling in for the long roast.

After a solid 90 minutes of roasting, the fennel crusted pork roast was ready to be served up to the hungry souls tempted and teased for 90 minutes with delicious wafting aromas from the oven. A welcome trade for last minute use of a working oven and reward for having survived an explosion. The only explosions that will be welcomed around here will be in the form of fireworks far overhead.

Salvaged roasted pork belly with fennel seed rub

Salvaged roasted pork belly with fennel seed rub

Our oven door was promptly replaced by the manufacturer and we’ve been assured that it was a once off fault. Yeah right. I still look at my oven warily when I turn it on. So, there’s potential danger lurking in every shiny pot, pan and sinister oven. Read up on the facts and decide for yourself whether the risks are relevant to you and whether they’re even worth worrying about. I for one see no risks with my current practical use of my cookware. Not that health risks are in any way laughing matters, but it pays to take the information we’re fed with a pinch of salt and a generous handful of commonsense.

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{ 15 comments… read them below or add one }

1 Vivienne June 4, 2011 at 11:30 pm

ohhh man! im glad none of you got hurt from the exploding oven!! initially i thought it was steam on the oven door and not shattered glass!! :( which brand of oven do you guys have anyway?! scarrry!

ive also been looking for a pan myself these days…am considering getting a silit fry pan but still doing my research.
Vivienne recently posted..Edamame beans pancakeMy Profile

2 Amanda June 5, 2011 at 9:04 pm

Wow – talk about adding a bit of a thrill to your day! If it is of any comfort to you, I understand that the fight, flight or freeze instinct is just that – innate – so you can’t be blamed for being pathetic.

3 Reemski June 6, 2011 at 1:02 pm

Far out. That ain’t cool!

4 Tina@foodboozeshoes June 6, 2011 at 4:07 pm

Oh gosh, a one-off hey? Until it happens again! (sorry, not helping). I think my response would involve a little more panic and screaming rather than your freezing (also not helpful).
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5 Adrian (Food Rehab) June 6, 2011 at 8:35 pm

Hells yes I ‘d 90 minutes for that hunk O pork! But yes, I’d also be a tad paranoid about my oven too…
Adrian (Food Rehab) recently posted..Interview with Adam Liaw Melbourne’s Good Food &amp Wine ShowMy Profile

6 Sara June 7, 2011 at 2:45 am

Hi There — I applaud the idea of creating a safer home, and because there’s so much misinformation out there about the Teflon® brand, I’m not surprised that you are concerned. I’m a representative of DuPont though, and hope you’ll let me share some information with you and your readers so that everyone can make truly informed decisions.

Regulatory agencies, consumer groups and health associations all have taken a close look at the Teflon® brand. This article highlights what they found — the bottom line is that you can use Teflon® non-stick without worry.


I’d truly be glad to share additional information about it if you are interested, and appreciate your consideration of this comment. Cheers, Sara.

7 Forager June 7, 2011 at 10:38 am

Hey Sara – Of course I’ll post your comment. I certainly don’t consider myself an expert on the subject and welcome both sides to voice if they choose to, if they have evidence supporting one argument or another. Readers need to make informed decisions.

8 Toby June 7, 2011 at 2:47 pm


On the toxity of teflon pans there was an interesting interview by Richard Fidler of two Canadian authors that included discussion of this.


Their book:

You’d probably enjoy it!

Toby recently posted..Miami University Photography competitionMy Profile

9 Sara (Belly Rumbles) June 8, 2011 at 6:09 pm

I too have had the joy of an exploding oven. Was finding glass for days, I was unlucky and it went everywhere. Actually happened when I closed the oven door of all things.
Sara (Belly Rumbles) recently posted..Assiette – 35 Friday 3 Course LunchMy Profile

10 Betty Pham June 15, 2011 at 1:10 pm

oh damn that is no good :(
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11 mademoiselle délicieuse June 15, 2011 at 10:11 pm

Oven concerns in my parents’ household were much funnier – my mother wouldn’t allow the use of baking paper as she was sure it’d catch on fire! So my first baking adventures involved lining pans with foil and only using foil muffin/cupcake cases as anything paper was banned. Ahhh, Chinese mothers!
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12 thatssoron June 21, 2011 at 11:44 pm

ok.. am goin down stairs to get some food now thanks ! its midnight! 😉

13 Gianna June 23, 2011 at 7:54 am

I don’t think it was your lack of flight or fight response, Trina.. I’m pretty sure it was you genuine concern for that beautiful roast!

14 Forager July 25, 2011 at 10:34 pm

Hey Vivienne – It’s a W*stinghouse and trust me, we were pretty shocked! Ooh – a silit pan, I was pretty tempted to get one in the US – they’re cheaper over there (well, everything seems to be!)

Hey Amanda – Oh. Er, I’ll tell the Co-pilot that my survival patheticness is innate and inbuilt. He’ll appreciate that..

Hey Reemski – Hell no it ain’t!

Hey Tina – I know, I can’t help but think the same thing (not helpful). You know how you stick your face close to the oven to peer at the contents to check if they’re done? Face and eyes pressed to the oven door? Yeah. Not happy whenever I use that oven..

Hey Adrian – The pork was thankfully salvaged so that was some consolation at least. And roast pork does go a long way to make me forget my worries

Hey Toby – Thanks – you’ve been sending on some great links my way – keep ’em coming!

Hey Sara – Ah, I wonder if we had the same brand.. Not right. Ovens should just explode when you’re using them normally. I wasn’t creating explosives – just roast pork!

Hey Betty – Nope. Not at all!

Hey Mademoiselle Delicieuse – Sounds like my mum’s concerns! Funny how there is no amount of logical reasoning that will make them change their mind..

Hey thatsoron – Midnight snack – the best! You definitely should be thanking me!

Hey Gianna – Haha, although pork and crackling weren’t far off the brain, they’re kind words, but I’m pretty sure my responses have thus far demonstrated I’m no Bear Grylls.

15 muse May 29, 2014 at 8:59 am

You are correct Teflon is everywhere in our daily life and over heat point it would release some dangerous element to the food. So get a good copper cookware with best conductivity maybe a better option
see Copper cookware

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