Frying Eggs and Air Quality Tests
41 comments
·September 16, 2025infecto
graeme
I've tested with oil. You don't see a large spike unless something is blackened or the oil smokes
Biggest generator of pwm during cooking is when things actually burn. Which can be just a very tiny portion of the food, like one black speck that came off and heated extra. This produces more pwm than the mass of oil and food.
dfxm12
what feels like cooking food in their bedroom
Aside from studio apartments, where space is at a huge premium, I'm having a hard time understanding what you mean by this. Can you elaborate?
infecto
Have you been into a western home? The stove may not have a hood, if it does have one it’s usually inadequate. The kitchen will be in an open space so anything you cook travels everywhere. The number of homes without range hoods is wild to me. Hence cooking in your bedroom, you cook and the whole house smells.
dfxm12
Yes, I've been in many Western homes, but never one without a hood over the stove. Adequacy of the hood seems like it's not going to be quantifiable or provable. I hope your analogy doesn't rely on this measure...
I also don't think "you cook and the whole house smells" fits the analogy of "cooking in your bedroom". The key feature of the bedroom is that it's where you sleep, get dressed, etc., not the smell.
wffurr
Externally vented hoods are now required in my town in Massachusetts. But I have lived in several places like you describe and it’s sub par.
moduspol
Even in nicer houses in the US, they’ll have a range hood but no intake air! And then I’ll hear neighbors complaining about it not working well because nobody tells you that if you don’t have make-up air, you also need to open a window for it to work well.
lotsofpulp
I have plenty of million dollar plus houses around me selling without any exhaust at all, just a cooktop on an island in the middle of the kitchen, and most of the times it is a gas cooktop! And in 80% of the houses, it's just a shitty microwave exhaust above the range.
So right off the bat, you're down $20k at least to remodel the kitchen so it has proper ventilation, assuming you cook.
Forget the health effects and whatnot, but are people not bothered by cooking smells pervading the house?
unbalancedevh
Good cooking smells delicious. Let it permeate!
namibj
My new kitchen will be separated from any other living spaces for exactly that reason; though the exhaust may need juicing.
amo1111
> Something weird though is that turning on my extractor fan didn’t really do much.
Does your extractor fan vent to the outside, or just recirculate through a filter? In my experience, people often overestimate how much protection ventilation provides. It mostly dilutes contaminants rather than removing or isolating them. For example, with moderately hazardous compounds, a fume hood works fine under normal use, but in the event of a spill it can’t bring levels back down quickly enough to protect the operator. In that kind of situation, an isolator makes far more sense or adding PPE, though that can be burdensome.
What really surprised me is how high the values get from just a single pan. It makes me wonder what it’s like in a commercial kitchen with multiple pans at higher temperatures, especially if the extractor fan fails and there’s no time to shut down operations to fix it.
Mistletoe
>In my experience, people often overestimate how much protection ventilation provides.
Do you have references to back this up that I could read? Assuming the same fan size, ventilation would act like a perfect filter and remove everything out of the room that the fan pushes, whereas a filter will allow some particles to pass and recirculate. Especially useless if it is those metal fiber filters that are in a range hood that just remove some grease.
mttch
Two things, no oil as others have suggested but also frying eggs does not require a very high temperature, around 150 Celsius and your eggs don’t look particularly browned (which is how I prefer them too) so you aren’t exercising the Maillard reaction, which generates the PM2.5. Try again with browning a fatty cut of beef or pork steak in oil which require higher temperatures where lots of browning is occurring and you are also closer to the smoke point of the oil.
Tade0
Those eggs appear to be on a non-stick pan, so without oil.
Try cooking with oil and you'll see PM levels go to enormous heights.
Aaargh20318
I have an air purifier in my bedroom. It measures PM1, PM2.5 and PM10 as well as TVOC (Total volatile organic components) and adjusts it's air intake according to the air quality. Usually it runs at very low speed and is inaudible, even at night.
When I start cooking downstairs, within a minute or so I hear the purifier upstairs ramp up to full speed.
andrewl
That sounds like the kind of air purifier I want. What brand/model is it?
progbits
Indeed, and I prefer short period of increased air pollution + ventilation and air filters, to nonstick pan and eating PFAS which is unavoidable (and unmeasurable at home).
onli
Afaik the nonstick pans are not emitting pollution in that sense, the food does not get contaminated, even if the surface peels off that is supposed to be benign. The problem is the production process, having already contaminated the drinking water of the whole world with PFAS - and that's the route where we get contaminated for real as well.
But who knows, maybe those pans are even more dangerous than currently known.
cassianoleal
If it's Teflon / PTFE, as long as you don't let it smoke you should be fine. The polymer chain is too large to enter your cells, so your body just expels them intact.
That's not to say you should go out and buy everything coated in PTFE. It generates tons of pollution when it's synthesized. I'm just saying there's no need to rush to throw away the ones you may already have at home - that might be counter-productive as you're now generating waste unnecessarily.
chao-
Do people normally not use oil with nonstick pans? I always use some regardless of pan because it crisps better and adds flavor.
nkrisc
Same. The primary benefit of the oil, I’ve found even in a non-stick pan, is better and more even transfer of heat and more even browning.
lotsofpulp
I couldn't imagine cooking without oil. Pan frying spices in oil is pretty much the first step of cooking for me.
tensorlibb
I've found just opening a window does the most to make a difference - in most European / US homes (even with propane / gas service) the "exhaust" just blows into the same room or a cabinet!
That said, I personally use the Breathe Airmonitor Plus [1] - I kept having issues with calibration with the temtop unit. Mostly decided on this one since it uses an NDIR sensor similar to my Aranet which I carry with me all the time.
hnuser123456
If only externally-extracting fans were a codified standard for stove hoods in the way that bathroom fans and dryer vents are.
ssimpson
Not sure about yours, but many extractor (vent) fans will just suck the air over a very loose filter and throw it back into the room. Many in the US are part of the over stove microwave and rarely vent at more than 250cfm (~7 m3/min) where specific vent fans that go outside can move upwards of 700-800cfm (20m3/min).
ksab
As someone who once did lab-based cooking studies (with a mass spectrometer), you would be surprised what is emitted from frying with oil.
I suggest frying some bacon and report back.
pxeger1
> Someone once said to me that cooking can increase particle pollution in the air to dangerous levels. Is this true? I suspect not.
Were they talking about gas hobs? Surely that's much worse than the electric/induction one you appear to be using.
crazygringo
No, gas combustion doesn't generate any significant amount of particles.
It produces CO2, NO2 and some CO. But it's not going to show anything on a PM2.5 meter.
The particles when frying come from the oil turning into smoke, as well as just aerosolization even well below the smoke point. These are what send PM2.5 levels skyrocketing.
When I sear a steak in cast iron, my PM2.5 levels go from their baseline of ~2 ug/m^3 to ~200–400. And course you can smell it in the air.
infecto
Gas combustion absolutely contributes to poorer air quality but I would argue that actually cooking (not what’s happening in this test) is much worse. Heating oil and cooking proteins will quickly fill a house. If you can smell it, the air quality has been reduced.
AdmiralAsshat
My favorite method of frying an egg is in a wok with oil. It gets amazingly crispy, rather than floppy, which is how it usually turns out in a conventional nonstick pan.
But it pretty consistently sets off the Coway air purifier in my kitchen when I do it...so I would assume frying with oil to the point of smoking does adversely affect air quality.
namibj
>smoking >bad air quality
.... That should be obvious though, right?
AdmiralAsshat
Sure, although it's interesting to see how long those pollutants linger, based on how long it takes my air purifier to return to "normal" quality. The egg fry will make it angry for about five minutes, maybe. By contrast, every time I fry up some bacon, the indicator will stay in the red zone for 15-20 minutes.
onli
To me measuring the air quality was interesting and surprising. Because like you said, how long the pollution lingers is surprising. And to me it wasn't obvious how bad the values get when cooking. I was aware of the kitchen smell traversing into the apartment, but hadn't realized how bad the air quality gets because of that.
vintermann
Low PM count in his bedroom? Good for him, but try right after making your bed. Nobody is so perfectly defoliated that they don't have dust in their bedroom.
Also, cooking of all kinds spikes PM levels in my experience. Maybe eggs in a 100% clean non-stick pan are an exception, but I doubt it if you can smell it.
esafak
> Something weird though is that turning on my extractor fan didn’t really do much.
Was it one of those useless microwave ones?
shireboy
Stealing from the comments: “I bet the eggs taste better”
Frying would require some sort of oil or fat and it’s hard to tell but the pan looks clean. Anything with oil will dramatically bump up those numbers. It’s intuitive just cleaning your kitchen, grease being cooked travels.
My one wish is the west adopted Chinese style kitchens. Even in new condo builds the kitchen will be isolated in a room you can close off, with an exterior wall and powerful exhaust vents. I always found it perplexing how ok folks are with what feels like cooking food in their bedroom.