How to remove VOCs from your home
I’ve spent the last two years dealing with mold toxicity from living in moldy buildings. In November 2022, I found (after much struggle that I’ll write about later) a mold-free apartment in a brand new building.
The good thing about moving into new construction is that it’s less likely to have mold1.
I quickly discovered the not good thing about new construction: volatile organic compounds (VOCs).
It’s common for people recovering from mold illness to be extra sensitive to chemicals and this manifests in all sorts of fun symptoms that vary by person. I my case, my face and tongue start tingling, my throat tightens, and I get fatigued and anxious. Not a pleasant feeling ever time you walk through your front door.
It took me a few weeks to figure out what was going on. Whenever I left the apartment, I felt better, and my symptoms would light up and then gradually increase the longer I was inside. And man, did it smell like chemicals.
So I went down the rabbit hole (i.e. Reddit) to see what I could do. What follows is a summary of the advice and techniques I discovered in about two weeks of research. I employed these to quickly lower the VOC levels in my indoor air and started feeling better almost immediately.
I’m posting them because most of the articles I’ve found online are not helpful, are missing some key factors of VOC control, or are just plain misleading. I have to give a ton of credit to the pseudonymous valpres on Reddit, Randy at Fike Analytical, one incredible PhD dissertation, and various internet anons.
I’m not a scientist or certified in any of this. I’m making that disclaimer not because I’m recommending anything dangerous, but because there is a possibility that the levels of VOCs are simply so high that it’s unsafe even with the remediation techniques I’m recommending or there’s something other than VOCs in your home that needs to be dealt with in another way — asbestos, radon, mold, a gas leak, carbon monoxide to name a few.
That being said, here’s what I did to get the VOCs under control and feel better within a couple weeks.
What are we dealing with?
VOCs are basically chemicals that are volatile at room temperature, meaning that they have a low boiling point and slowly evaporate into the air at room temperature. And then you breathe them in.
VOCs are in a lot of the things we use or interact with on a daily basis — paint, carpeting, sealants, lacquers, etc. New construction has a lot of them, as does new furniture, new mattresses, new cars, etc.
It’s pretty much impossible to completely avoid them altogether, unless you live in a tent in the woods. Just kidding, the tent has VOCs.
The good news is that they off-gas, or dissipate, meaning that eventually the new sofa you bought with a slightly chemical smell will eventually become less toxic over time as the VOCs evaporate and leave your home through a window, the HVAC system, or a carbon filter (more on filters below).
I’ve read that most VOCs dissipate within 3 to 24 months, depending on the chemical. Don’t quote me on that, but the thing to know is that eventually the VOCs in your home will dissipate on their own. It’s a downhill battle.
But you’re feeling bad now and don’t want to wait 3 to 24 months, so what can you do?
First, you want fresh air flowing into the house.
The easiest way you can open windows on opposite sides of the house to create a cross-breeze (if it’s not too cold where you are).
If you want to speed up the process, get a high-speed fan and have it blow out of one of the windows to increase airflow out.
Fresh air in, toxic air out. Pretty simple.
When I first tackled the problem, I went all-in on fresh air, with a high-speed fan blowing out one window and another blowing in another window. And I felt WAY worse.
Why? Well, when I was doing this in January, the humidity in LA was quite high, around 80% outside.2.
Some more research led me to read “Effect of Relative Humidity on Chemical Off-Gassing in Residences” by the chemical engineer Miriam Nchekwubechukwu Nnadili. Here’s an excerpt of her conclusion:
1. Transient increases in RH [relative humidity] can lead to large (factor of 5 or more) increases in the levels of thermally-stable organic compounds in indoor air. This is evident from the field experimental results for which 86% of the 78 bin analyses (13 events x 6 bins) showed an increase in abundance during humidification. This is consistent with results from the controlled chamber experiments, for which 92% of the bins had an increase in chemical abundance during
2. Off-gassing from household materials and desorption of previously sorbed species appear to be major contributors of chemical emissions during transient increases in RH.
She ran experiments in sealed chambers to detect the increase of VOCs in the air at different humidity levels and found that increased humidity can increase VOC release by a factor of 5 or more.
In other words, you want to keep the indoor humidity level low, unless your goal is to release the gasses as quickly as possible and create an ideal environment for mold.
I personally target an indoor humidity of around 35-40% with a dehumidifier. I bought one that has a pump with a tube that I can run out of a window so I don’t have to empty the bucket every time it fills up (or risk standing water sitting in a dark container when I’m away from home).
Carbon air filters
There’s a lot of confusion out there about air filters and VOCs. The truth, as far as my amateur understanding goes, is that your typical air filter, even one with a HEPA filter, will not do anything to trap and remove VOCs from the air (although they can be great for fine particulates, bacteria, viruses, mold spores, etc.).
To remove VOCs, you need a carbon filter.
There are some consumer-grade air filters that market themselves for VOC removal. Usually, they combine a HEPA filter with a small carbon filter. These devices don’t have enough carbon in them to move the needle — there’s not enough carbon to begin with and and carbon filters fill up very quickly in a high-VOC environment.
I initially experimented with a HealthMate Plus, which has a lot more carbon than a typical consumer air purifier. It did help, but only for a few weeks.
The problem is that carbon filters get saturated quickly and there are much more cost-effective options out there, thanks to the burgeoning cannabis industry.
I bought a TerraBloom 8″ filter + fan and I’ve been very happy with it. The VOC levels in my apartment declined noticeably after installing it, both subjectively in terms of odor and my symptoms my VOC monitor also showed an improvement (more on monitors below).
The aforementioned valpres also recommends Vortex filters.
These filters are marketed to industrial customers but they work just fine in the home and I think the TerraBloom actually looks pretty good, although it’s a bit loud. You can run it on a lower speed (it comes with a variable speed controller) to keep the noise down and extend the life of the filter.
I recommend running them in your bedroom while sleeping and then in whatever room you spend the most time in during the day.
Sometimes, when it’s warm enough to leave my windows open and not too humid, I run a regular fan out of one window to use the natural airflow method and then I just use the carbon filter at night when I want to close the windows.
Carbon filters fill up quickly
Carbon filters saturate very quickly in a high-VOC environment (my first TerraBloom filled up in about 2 weeks after running 24/7).
I admit that I don’t have a scientific way of knowing when a filter is saturated — I guess based on the relative VOC levels shown on my VOC monitor, the level of chemical odor in the apartment, and how I’m feeling.
When the filter saturates, you have two options: you can either replace the filter (the fan doesn’t need to be replaced) or you can try and regenerate the filter by letting it run outside.
I’ve only experimented with regeneration a bit and I don’t think it worked very well because the air was cool and humid when I tried, so I suspect that any off-gassing from the filter was canceled out by moisture capture, but see here for a good discussion of filter regeneration.
You can also extend the life of the filter by running it on a low speed or turning it off when you’re not home.
And the more I’ve employed these techniques, the less important they become — VOCs dissipate naturally and unlike mold, they don’t regenerate, so if you’re circulating fresh air and filtering, the ambient levels of VOCs will gradually go down to a point where I can forget to turn the filter on for a day and not even notice.
I filled up the my first TerraBloom very quickly because the VOCs were really high and I just wanted to get the levels down to something I could tolerate, but since then, I’ve run them at slower speeds. In a year, I expect that I’ll only need to run the filter occasionally or when I buy new furniture.
Keep in mind that high humidity also clogs up carbon filters so there’s another reason to control humidity.
Monitoring VOC levels
Normally, I’d put diagnostic stuff at the top, but the issue here is that consumer-grade VOC monitors aren’t very accurate and may only half a useful life of six months.
I bought a TemTop Air Quality Monitor and while I don’t think the readings are very accurate in absolute terms, I do think there’s some signal in terms of relative levels. That has helped me see if the VOC levels go up or down when I change a filter, open a window, etc.
If it’s scientific precision that you seek, then you can order an at-home test from Fike Analytical. I ordered a test kit from them. They sent me a little pump and a collection test tube, which I set up at home for a few hours and then shipped it off to a lab. When the results came in, the owner spent 45 minutes walking me through every chemical detected, where it might come from, and what to do about it.
Do you need this level of precision?
I think it depends on the situation. I wanted one partly because I wanted to make sure there wasn’t something really toxic that I should know about and partly because I’m just curious about this stuff.
Or maybe you live with someone who thinks your crazy when you say the paint in the house is making you sick and you need hard evidence.3
Reduce chemical exposure
Apart from building materials, there are two major ways you’re likely to bring new sources of VOCs into your home.
The first is furniture — new furniture tends to have paint, flame retardant, lacquers, etc. Some people recommend leaving their new furniture outside for a few days to let it off-gas outside before bringing it in.
I’ve mostly not done this when it’s humid outside because I worry about mold growing in humid conditions. Not sure if that’s a valid fear, but given the choice between mold and VOCs, I’ll always choose VOCs.
Another option is to leave the furniture in a room you don’t spend much time in for a week or two before moving it into your bedroom, living room, etc.
The other way you probably bring VOCs in is through personal care items and cleaning products. There’s a lot of toxic stuff out there and I don’t recommend applying it directly to your skin or spraying it all over your house.
For safe alternatives, the Environmental Working Group (EWG) provides databases of non-toxic personal care products and common household products.
If you’re on a tight budget, maybe because you just threw out all your worldly possessions because they were contaminated with mycotoxins, you can start with the least expensive methods (opening windows) and then move on to more aggressive solutions as needed.
If you’re lucky enough to live in a low-humidity area, then opening a couple windows and creating a cross-breeze might be all you need.
And VOCs do go away eventually, so things will get better over time on their own. Air filters are expensive, but you might only need them for a few months, until the levels get down to a level where they’re not making you sick.
Less likely, but not guaranteed! There are cases where mold grows in a building, especially in the HVAC system, during construction. ↩
Most people think of LA as a really dry city because it hardly ever rains, this winter notwithstanding, but the average humidity in LA is 60%. ↩
I’ve talked to a dozen people that live in my building and none of them noticed any kind of chemical odor in their apartments, so if you’re really sensitive, you’ll sense things that others don’t. ↩