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The Health Hazards of Plug-In Air Fresheners (2017) (indoordoctor.com)
97 points by tentacleuno 9 days ago | hide | past | favorite | 98 comments

“Air Fresheners” rank right up there with leaded gas, asbestos brake pads, and coal plants: two decades from now we’ll look back with regret and astonishment at how stupid and irresponsible an idea it was. Deliberate inhalation of hormone-disrupting, liver-abusing, likely carcinogenic poisons, all in the name of smelling like a pine forest glade. Inane.

I’d argue the other three at least have highly functional qualities and are likely the best functioning alternatives (on at least some dimensions) at the time of introduction in a way/to a degree that air fresheners are not.

A pot on the stove with lemon, vanilla, or cinnamon or some actual flowers/pine seem to be perfectly reasonable substitutes for the air fresheners.

As long as the stove isn't a gas stove, since that's probably another one we can add to the list of things that we'll likely look back on with regret :)

While I agree that gas stoves put out more VOCs than most people would imagine, the fact that humans have been cooking inside on either wood or gas stoves for many hundreds of years, gives testament to the idea that it can’t really be /that/ detrimental to human health. Sure it would be better without them, but I’d imagine that the health gains would be marginal at best.

Wood smoke is actually pretty bad for your lungs. It's a known carcinogen, although not quite as bad as coal:


Its the compounding of toxins... just 80 years ago before air conditioners most people had the windows open and with so many people working inside all day... most homes are toxic. Open your windows people - get some fresh air (hopefully where you live).

> the fact that humans have been cooking inside on either wood or gas stoves for many hundreds of years

Cooking inside using wood kills a lot of people each year.


> Around 3 billion people cook using polluting open fires or simple stoves fuelled by kerosene, biomass (wood, animal dung and crop waste) and coal.

> Each year, close to 4 million people die prematurely from illness attributable to household air pollution from inefficient cooking practices using polluting stoves paired with solid fuels and kerosene.

> Household air pollution causes noncommunicable diseases including stroke, ischaemic heart disease, chronic obstructive pulmonary disease (COPD) and lung cancer.

> Close to half of deaths due to pneumonia among children under 5 years of age are caused by particulate matter (soot) inhaled from household air pollution.

The counter argument to this is that there are so many health conditions that are getting increasingly bad which we have no explanation for since so many things changed at the same time.

I wouldn't be surprised if chronic inhalation of natural lemon or pine scent were unhealthy too. Limonene can cause skin irritation for example. Plants generally evolved essential oils to avoid being eaten, it kind of makes sense that inhaling them might be unhealthy.

Agreed. Asbestos is a wonder material that the world is unironically worse-off without. To be fair, putting it in brake pads which get worn down into dust probably wasn't a great idea...

I'm curious what you feel is a good use for asbestos?

As far as I'm concerned, the fact that it may or may not be in any house I own is a huge problem. It makes renovation and remodeling a huge liability.

Its thermal insulation/fireproofing properties are incredible, it's basically a material out of science fiction.

A few years ago I acquired a pair of asbestos gloves at a flea market. They are absolutely mind blowing. I have held glowing red-hot pieces of metal for upwards of a minute at a time with my hands only feeling mildly warm. You might be able to do this with certain welding gloves, but they would be thick like oven mitts, leaving you with basically no dexterity. These asbestos gloves are no thicker than ordinary leather work gloves, are lightweight and permit your full range of motion. As an experiment to see how far I could push them, I poured a bit of molten lead over them (my hand was not inside this time) and it just beaded up and wicked off, like water does on a waxy or oily surface. If my hand was inside, I'm sure it would have been fine. I'd even go so far as to say that you'd probably be fine if you submerged your hand in molten metal, since the pores in the woven asbestos are so small that the metal would probably be prevented from seeping in by its surface tension.

All that said, they probably do release microscopic fibers into the air, so I wear an N95 when using them and store them in a sealed ziploc bag.


check this out too https://www.youtube.com/watch?v=yuwUXGyWlHQ

You should wear an N100 when you wear your gloves. Asbestos fibres can easily bypass an N95.


I think it depends on the level of fibre release you expect. I don't think the issue is that the fibres bypass an N95 mask, but that if there are many fibres in the air you want to filter out a much higher proportion than 95%.

In the UK for non-licensed work (removing things like asbestos floor tiles which have low levels of asbestos that are bound in another substrate) you only need to wear the equivalent of an N95 mask.

Noted, thanks! Is there any relevant difference between N100 and P100? I think my local hardware store has P100 filters in stock

P = prevents oil penetration

N = doesn't prevent oil penetration

100 = 99.97% effective against pm2.5 infiltration (the hardest size to filter)

I'd like to see a chemical lab without asbestos.

When used by professionals, it's an incredible heat shield.

In the US, it should not be in any newer house since the 1990s or even the 1980s.


Where will fabric softener end up?

Somehow I grew up in a family that never used fabric softener, or those little disposable dryer sheets. And I still don't understand the point. Fabric is already soft - "static cling" hasn't been a problem my entire life. What are these things for?

Fabric can end up hard and abrasive if washed in hard water and left to air-dry.

Fabric softeners offset that to some extent, although in soft water areas or for people who tumble dry their clothes, I don't see any benefits.

I bet you live in a warm climate. I grew up in the US south. And now, after living years in California, I have noticed that static cling is not really a thing here either. I'm not sure if cooler weather or higher humidity had to do with it, or just the type of clothes that you wear in cooler climates, but I distinctly remember having a lot of trouble peeling different articles of clothing apart after taking them out of the dryer and just getting shocked all over the place. If you took clothes out of the dryer in the dark, the room would light up dimly from all the sparks flying.

I grew up in Pennsylvania and it certainly got dry and staticky in the house - I've been shocked by many a door knob and now that you mention it I did sometimes have to peel certain articles apart (e.g. fleece) when taking them out of the dryer. I guess I never thought of that as a problem that needed to be solved though.

I think if you did the laundry for an entire family on a regular basis, you might consider a problem that needs solving.

Or dish soap?

For the first time I noticed Dawn Dish soap listing its 10 plus ingredients in clear print on the front label.

I assumed it was lawyers being cautious. I do rinse better now than in the past though.

(Dawn soap is a great degreaser. I like the product, but I am reading labels more these days.)

And not just doing it the more rational way, by soaking something porus with dilute alpha pinene

>“Air Fresheners” rank right up there with leaded gas, asbestos brake pads, and coal plants: two decades from now we’ll look back...

If asbestos and lead are any indication I'm sure joe blow in 20yr will be writing long Reddit and HN rants about how <insert carcinogenic air freshener chemical you shouldn't atomize in an enclosed space> is nothing but pure evil and the CEOs of <insert company> should be lined up and shot for using it in <insert industrial application where there are so many more poisonous contaminants about that a little lead in your bearing surfaces or asbestos in your insulating materials doesn't make the environment any more hazardous>.

And if it turns out that those CEOs had secret, buried research indicating toxicity, and continued to sell and even funded bogus research to counteract the legitimate stuff, then it will be justified.

Carbon scrubbers are the healthy, bulletproof solution to eliminating stubborn odors in the home. Not the tiny little activated charcoal sheets that are in some air purifiers, they are too small to do that much, I'm talking about the cylindrical ones made for indoor marijuana grows. I used to live in a small NYC apartment with a cat. You could not smell any pet smell once I got a carbon scrubber going in there. If you get a decent variable speed fan it's going to be no louder than a regular consumer air purifier. If your only concern is odor, it's going to be more cost effective in the long run than an air purifier too.

Any recommendations on affordable ones? I love my cats but you are spot on about the smell, I currently use the plug in air fresheners when I have company but take them out as soon as they leave.

I like this fan a lot: https://smile.amazon.com/dp/B07FPFVZTZ

I had a previous speed-controlled fan that had an annoying buzz at low speed. This AC Infinity one is very good though. I would not cheap out on the fan. I had this set on the lowest setting, and also had an outlet timer plugged in so it turned off for several hours in the middle of the night.

Conversely I don't think the carbon scrubber itself matters much. I think they're basically fungible commodities. Here is a perfectly fine one: https://smile.amazon.com/dp/B01731MLFK

For regular household use (aka not growing marijuana) either 4" or 6" is appropriate. I went with the 6" because I thought it would most likely be quieter than 4" for moving the same amount of air. You just have to make sure you get the same size inline fan and carbon scrubber.

How do you setup the fan? Are you running any ducting, or do you just plop/mount the fan somewhere, turn it on and it works?

Just curious because my wife is bothered by a lot of odors and we've tried everything. For example, the other night, my wife woke up and had to close the windows in the house because a skunk smell was so strong. But, all I could smell was clean fresh night air. Hah.

I was not running any ducting. I just sat the filter down, with the open end facing up, and you can set the fan right on top of it, it will nest inside it slightly. So it was drawing in dirty air from all sides and then just blowing out the top. This was placed in the same closet that my cat's litter box was in.

Lovely, thanks! I'm going to give it a whirl. :)

Totally possible to DIY- they're not super high tech.


My mother was one of the super skeptical types, so she wouldn’t allow the plug in fresheners in the house (or the spray kind either) — it was open windows, sunlight, and very limited cleaning products. I’m pretty thankful about that skepticism and intend to keep that momentum when I have kids.

My mum was the same, including with plastic food containers. Turns out those are really bad as well. It’s also amazing how we continue to use products knowing they are toxic.

My parents consciously moved away from the city and big roads to have their kids.

Which I reversed in my infinite 20 something wisdom.

If you ever experience a skin condition that seemingly won't go away and is surprisingly painful, you'll get hip to the scam that are cleaning products quite quickly.

They can all be made at home, with 3 or 4 ingredients. The supplies will last a lifetime and you don't produce any non recyclable plastic bottles (another scam!).

> They can all be made at home, with 3 or 4 ingredients.

I've done a few experiments with home made saponification in the past but I never really considered this for other cleaning products.

Can you share some resources or experience on this?

This is Lisa Bronner of Dr. Bronners which I used as a starting point:


There is also a girl who hasn't used any plastic for years and makes everything herself including beauty products:


Lots on Youtube in general. Again, I do it because I needed to, I don't want to preach or shame.

Your mom was right. Sunlight disinfects rooms too.


Had a cat that kept going to the vet with kidney problems.

Couldn't figure out what the problem was, but eventually tracked it down to the plug-in air freshener next to her perch.

Got rid of it and the bloodwork started coming back normal almost instantly.

Do you recall what specific test was out of normal range? (Was it creatinine, urea, etc.)

I don't, unfortunately.

A similar product in Korea killed quite a lot of people a few years ago.


I've tried and failed several times to find an ultrasonic humidifier with a basin that's dishwasher safe.

It's really amazing to me that "how do you clean this fucking thing?" is such a nebulous concept for the engineers of these devices.

Ideally you use distilled water in a humidifier, which should really help to keep it clean. But that can be a pain.

I add a small amount of bleach every other time I fill the tank (a few drops - if you can smell it you've added too much) and once a week I empty it out entirely, wipe it down, and let it dry completely. And, of course, if I'm turning it off for longer than 12 hours or so, I empty it out.

you're supposed to chuck it; not unlike the philips air fryer. disassembly and cleaning it thoroughly takes many hours.

The chemical which caused the issue, if you're interested: https://en.wikipedia.org/wiki/Polyhexamethylene_guanidine

Another hit from the company who produced the sanitizer:

Suboxone maker Reckitt Benckiser to pay $1.4 billion in largest opioid settlement in US history


Another product they sell: https://www.reckitt.com/brands/air-wick/

So Korean fan death may not be a thing but this certainly doesn't help.

> Natural essential oils, for example, can be used to make safe home scenting products, such as “DIY” scented candles.

This sentence comes after a one sentence gap from a paragraph warning that the plug-ins contain volatile organic compounds(VOCs). Natural essential oils also contain VOCs. It’s how you smell them.

Burning candles also releases VOCs (and soot) into the air. My old roommate was a daily candle burner, and the walls in her bedroom ended up absolutely covered in soot after a few years.

Not only that, many (but not all) essential oils are very toxic to cats and maybe other pets too - blanketly calling them "safe" is just plain wrong. Like very, very wrong.

It's probably not a good idea to diffuse essential oils in general, they are VOCs after all, but it's an especially bad idea if you have pets.

On top of that, essential oil purity is probably not exactly well regulated. Depending what chemicals are used to do the extraction, there can be nasty stuff left over not to mention adulterants or other random stuff.

It might be more accurate to say that natural essential oils are VOCs.

And the essential comes from the fact that the oils are the essence of the plants(what remains when you boil one for a really long time), not because they are essential for humans...

Don't use candle essential oil diffusers. Candles burn too hot and burn the things you don't want to burn. There are electricly heated diffusers that warm up the oil to a lower temperature. But, don't use essential oil diffusers if you have pets. Pets can be extremely sensitive to essential oils and some are toxic to some pets while safe to humans. There are ways to treat pets with essential oils, but the process is very delicate. You essentially open a bottle and put it at a distance from your pet. If the pet approaches it himself and shows signs of liking it, you can look into ways of incorporating some of this oil into pet's life, but gently so as to not overwhelm him. For human use, just smell it out of the bottle or rub it on specific points on your body. Look up relevant literature for details. Most important thing is that just by smelling it you can immediately tell if that specific essential oil is good for you. Don't use them just because someone said they're beneficial.

The article mentions a study conducted by the Nation Resources Defence Council (NRDC), I think this is the study report with more details, including detected concentrations: https://www.nrdc.org/sites/default/files/airfresheners.pdf

I have always wondered why these things are a allowed to be called "Air Fresheners". They don't make the air fresher, they mask bad odors, so they should be called Air Scenters. I've always felt a bit alone in this but I much prefer a bit of residual faecal scent left by a ventilation system than the heavy blanked smell of an Air "Freshener", I could only imagine what filth it was hiding. These things are the cheap alternative to true fresh(er) air.

> They don't make the air fresher, they mask bad odors

I read a little while ago there are some which just add scent to mask the smell, but others have a doughnut shaped molecule which captures the smelly molecule. It doesn't 'clean' as such and does nothing to stop the source of the smell though so perhaps calling it masking is correct.

I don't know enough about the specific science of cyclodextrin, I've put a couple of links below.

https://www.direct365.co.uk/blog/how-air-fresheners-work/ > The key to odour eliminating air fresheners is a molecule called cyclodextrin. This is a donut shaped molecule suspended in a water carrier. Due to cyclodextrin’s hydrophobic interior, it attracts the odour molecules in the air. As the water dries, the molecules on the interior of the cyclodextrin are encapsulated inside, therefore reducing their volatility and minimising their smell.

https://helix.northwestern.edu/blog/2015/06/take-whiff-chemi... > When you spray Febreze the hydrophobic cavity of the β-cyclodextrin traps these volatile, odor causing molecules, preventing the molecules from binding to the odor receptors in your nose

We should call them "Smell blockers" or maybe "Scent blinder"

Exactly. It's misleading marketing, if not straight out lying.

I think candles should contain large black and white warning stickers like cigarettes.

Are the risks and consequences comparable?

Paraffin candles release benzene and toluene at a minimum. Then factor in the amount of soot candles will readily produce when people don't trim the wicks between uses (and cheap candles are sooty no matter what you do) and, yeah.

Only if you inhale.

This article might be completely factually correct but its overall quality is pretty bad. It doesn't tell you whether these chemicals are found in the liquid, in the vapor, or in both. No exploration of what the vaporization process does to these chemicals or whether there are types of plug-in fresheners that don't contain hazardous chemicals. No attempt to quantify what is and isn't a dangerous concentration. If my brother keeps one in his closed bathroom do I need to wake him up to yank it out? If I only have one freshener and it's in the big living room is it safe? Are there any filtration or neutralization methods that let users keep most of the scent while being safer?

Then the big question, are scented candles just as bad?

This is a kernel of good info but damn it could've been so much better.

Lots of answers to your questions aren't available.

Safe concentrations of many things aren't known for humans, because studying them is very difficult (effects over many decades, ethics problems with experimenting on people)

You don't have to be very smart to figure that out. I get sick only from the slightest smell coming out of those things.

Oops, left out a word in the title. The woes of manually coping text...


Junk science peddler.

These things have always been pretty obviously uncomfortable for me to be around, since way before I've come across research like this. Have you considered that your body just doesn't have the capacity to notice it? A poor sense of smell is possible, and is a risk factor for many things.

How about smelly candles? They work pretty well just lighting them for a few minutes a day.

The cheap ones are all petroleum-based, and if you get an unscented one you can really tell. Gross. Cheap scented ones still smell of it, even. Beeswax smells nice, even unscented, but is really expensive (if you're using them more than occasionally). Soy's OK and priced in between. A little harder to find than the petroleum ones, but that's not an issue if you're shopping online.

Anyway, as another poster noted, rarely is anything burning healthy to be around, even if it smells nice.

Why not just have a clean and well ventilated space?

I mean, sure, but it’s worth remembering that there are plenty of people who don’t have unilateral control over their living space or who find themselves in other situations where that isn't an immediately practical solution.

College kids in dorms, working adults with roommates, residents of cities with bad outdoor air quality, etc.

A $200 air purifier can make a world of difference: https://www.nytimes.com/wirecutter/reviews/best-air-purifier... (I own a Coway Airmega 200M.)

I bought a Temtop monitor to verify if the "smart mode" (where it only runs if the air quality is low): https://www.amazon.com/gp/product/B07DHXQXGK/

I live in Los Angeles where the air quality isn't that great and in a rented apartment where I have limited choices. The air purifier made a dramatic difference in the first hour I had it and now it keeps the PM2.5 reading down to around 2-4 with minimal cycling.

I don't have any inside info, but I'd guess that the "people who use plug-ins to cover endemically bad smells in their living space" and the "people for whom a $200 air purifier is a viable solution" markets don't have a ton of overlap.

IIRC box fan + filter works as well as expensive systems.

>A $200 air purifier

Minimum wage is $7.25 in many states. Over 27 hours of gross income to buy that purifier.

The median income in the U.S. was $31,133 in 2019, putting that air purifier at over 13 hours of gross income.

I've been at my job 15 years, in the rare event that overtime is available a $200 air purifier would cost me approximately the net income of 10 hours of overtime.

Down to 2-4 from what level unfiltered?

How large a room is that in?

Doesn't mean you need to make the indoor air even worse.

You can handle most bad smells by having good habits (taking out the trash, not leaving food sitting around, washing clothes, etc). If it's your house in general, you should probably fix it instead of masking it, because it's probably mold.

It doesn't matter how good your own habits are if your roommate doesn't share them, for example, and not everyone has the power to quickly change their circumstance.

Just saying there's room for a little sympathy here.

Combustion byproducts are also known to be quite harmful to the human body.

At the end of the article, they suggest looking for natural essential oil candles / making your own if you need to.

Just as toxic if not worse is laundry detergent and especially fabric softener (scented of course).

Here is a list of just SOME of the toxic chemicals found in commercial fabric softeners:

Alpha Terpineol: can cause central nervous damage and respiratory problems Camphor: causes central nervous disorders, is easily absorbed through skin Chloroform: a carcinogenic neurotoxin preferred by Ted Bundy Benzyl Acetate: linked to pancreatic cancer Benyl Alcohol: respiratory tract irritant Ethanol: on the EPA’s “hazardous waste” list, can cause central nervous system disorders Ethyl Acetate: a narcotic on the EPA’s “hazardous waste” list Limonene: a known carcinogen that irritates eyes and skin Linalool: causes central nervous system disorders and depresses heart activity

Alle Ding sind Gift und nichts ohn' Gift; allein die Dosis macht, das ein Ding kein Gift ist.

Camphor occurs naturally in the tree from which it takes its name, and also basil and rosemary naturally contain it in large quantities. Its lethal dose is reasonably small, under a gram for children, but its pungent odor seems to prevent most poisonings, and it seems to have no cumulative toxicity despite widespread use as an inhalant (for example, to alleviate symptoms of colds). A typical case report reads:

> A 3-year-old girl ingested 700 mg camphor from 1 tablespoon of Vicks VapoRub (R). This product had also been placed in her nostrils twice daily for 5 months. Grand-mal seizures occurred 2 h after ingestion. Coma and respiratory depression lasted 21 h. Full recovery ensued (Phelan, 1976).

Benzyl acetate and benzyl alcohol are produced naturally by jasmine flowers (they're the major constituent of their scent) and the ylang-ylang tree. Benzyl alcohol is also a constituent of castoreum. It can also strip the paint off your walls and destroy your corneas.

Chloroform is produced by many kinds of seaweed, perhaps by soil fungus, and in abundance by chlorinated drinking water.

Most of the other toxic chemicals here have been covered by other posters.

Ethanol, though, that's a huge social problem; aside from the cognitive impairments it's best known for, it may be the single chemical poison responsible for the largest number of yearly human deaths due to its addictive nature. Fortunately, the amount used in fabric softeners is typically about a thousandth of the dose needed to produce toxic effects.

Alpha Terpineol is in pine trees.

Benzyl Alcohol is in many plants and foods.

Ethanol is, well, ethanol.

Ethyl Acetate is found in many alcoholic beverages and is a simple ester of ethanol and acetic acid(vinegar).

Limonene is orange oil, found in citrus peels.

Linalool is found in many spices and flowers.

I'm not sure if you're seriously trying to scare people or making a sarcastic 'di-hydrogen monoxide' style joke.

I imagine a lot of this stuff is only a risk in certain quantities or forms which you rarely encounter. I find it funny how many basic things we use in food have somewhat high scores on that hazard diamond.

>Alpha Terpineol is in pine trees.

Are you trying to argue it is safe because it is natural?

Terpineol, and other various other chemicals in woods, can cause skin/eye/mucous membrane irritation. Inhale enough terpineol and you can cause permanent lung damage.

Turpentine (which terpineol is a derivative of), which comes from pine trees, is bad stuff. It can cause kidney damage, bleeding in the lungs, etc. Inhaling it can even cause central nervous system damage and can be immediately fatal in high enough concentration.

No, I'm saying you're probably exposed to it anyway, so keep your fears in perspective.

I've learned to avoid using fabric softener, but any time I'm exposed to it (in other people's houses), I get a frightening lung reaction; some wheezing initially, then my chest seizes up making me feel like I can barely breathe at all. I think it's a protective anxiety reaction to warn me to avoid it, rather than an actual dangerous allergic reaction, but there's something about it my body really doesn't like. I don't have any other allergies or asthma normally these days; I had dust/mite-related asthma as a child but have mostly grown out of it. That fabric softener reaction is the only reaction of that kind I've noticed in about the past 15 years.

> Ethanol: on the EPA’s “hazardous waste” list, can cause central nervous system disorders

And with that you've demonstrated that your entire list isn't likely to be grounded in reality.

For those that might not know, ethanol is the "alcohol" in "alcoholic beverages."

That is technically correct, technically.

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