Healthy Interiors

There are a few things you can do to prevent infiltration of fragrance, smoke, pesticides, cleaning products, and other chemicals from entering your house.

Whether the offending chemicals are coming from a neighbor with an adjoining wall in an apartment or a duplex, another house, or the outdoor air, the main strategies are similar.

Read through all the strategies and adjust them to your circumstance.

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1. Airseal Your Home

The first thing you can do is find and seal any small areas where air could find its way through. In an apartment, you cannot do this perfectly but you can still make an impact.

• Airseal along the baseboards wherever there is a gap or where caulking is coming loose (or was never applied) – both the top of the baseboard and bottom of the baseboard. Use AFM Caulking Compound if you want it to be paintable and neutral cure silicone (or this one from Amazon) if you don’t need it to be paintable.
• Caulk around any fixtures that are on the shared wall or the exterior walls if that is where the odors are coming in – light fixtures, fire alarms, fire sprinklers, lights, etc.
• Place gasket covers under the electrical outlets and light switch plates. These are foam gaskets that you can buy from Amazon.
• Patch any holes in the drywall with a non-toxic dry mix drywall mud (you can use premixed spackle but only if you are not that sensitive to VOCs).
• Check the caulking and replace it if necessary around windows and doors.

2. Find Out if Your HVAC System Brings in Air

You want to get to know how your HVAC system works so that you can find out if it’s bringing in air, when and where it’s bringing in air, and if that air is filtered.

Some systems have fresh air intakes, some have ways for “make up air” to come in to replace exhausted air – those can be passive or active, some homes have air exchangers, known as ERVs or HRVs, which move air in and then out.

The photo on the left is a passive make up air vent with a small filter on it.

You will want to know if these systems have filters on them (and can you add or replace them), where they bring air in, and how can you control them if needed to either stop air from coming in or to control when it comes in.

The photo on the left is an ERV air exchanger which brings air in and moves air out in a balanced way. It has MERV filters on it.

3. Control Negative Pressure to Prevent Air Infiltration

Any appliance that moves air out creates a vacuum that causes air to be sucked in through any route it can find. This is usually through small leaks that are found all over most buildings. This is the main way that contaminants are getting pulled into the building.

Even if you air-sealed as much as you can from the interior side, there is only so much you can do after a home is built. Plus when you are running exhaust in any way air still needs to come back in from somewhere, so you can’t stop this from happening in unpredictable ways and locations (unless you have dedicated “make up air”, which is not very common).

Which appliances create negative pressure:

• Portable AC units that have only one hose (use a dual hose portable AC unit instead)
• Exhaust fans in bathrooms
• Exhaust fans/range hoods over the stove or microwave if they exhaust to the outside (not just those grease catchers)
• Central vacuums
• Dryers
• Some woodstoves

When you run these appliances you are essentially pulling in air through any little place it can and this causes your neighbor’s chemicals or outdoor contaminants like smoke to infiltrate the house.

To stop this from happening only run these at times of the day when the offending pollutant is not being used by your neighbors or in the community.

If that is not possible you will want to provide easy access to make up air through a window that is not on the side of the building where the fragrance, smoke, or pesticides are coming from.

If that also doesn’t work in your situation, you can consider bringing in filtered make up air (see below section).

4. Use Positive Pressure When Needed

The IQ Air Multigas has a fresh air intake (pictured above). Instead of filtering your indoor air, it brings in fresh air from outside and filters that without exhausting any air outside.

This could be used to keep out contaminants in a few ways.

If you use this without the same amount of corresponding exhausted air, you are creating positive pressure. This is pushing air out through all those cracks and crevices where those contaminants were passively or actively making their way inside.

This can work really well to keep anything from leaching in. But this can’t be used in all climates at all times of the year. Especially in the winter in cold climates, this can’t be used, as there is a risk of this causing mold behind the walls.

You could also balance this with your exhausted air. You will need to measure the CFM of both of those to balance it. What that could do is allow you to use your exhaust fans when needed but control the air that is coming in so that it doesn’t bring pollutants in through all the small cracks and crevices in an uncontrolled way, but through this one controlled location (the IQ Air).

This also ensures that the replacement air is highly filtered.

If the contaminant is in the outdoor air on all sides – like forest fires – then you might still be able to use this highly filtered outside air, especially if you do need to use your exhaust fans.

If the outdoor contaminant is something that is short-lived, like a one-time pesticide spray then I would eliminate all negative and positive pressure for that time and seal things up as well as you can.

As far as I know, you can only buy this fresh air intake for the IQ air directly through their website. I have not seen any other air purifier companies that make something like this.

Related Posts:

• How to sequester offgassing of items
• How to offgas new furniture
• How to offgas a new house
• How to mitigate and seal fragrance and smoke

Corinne Segura is a Building Biologist Practitioner with 7 years of experience helping others create healthy homes.

Did you find this post helpful? If so you can buy me a coffee to support the research behind this blog. Thank you!

The first thing to do is to choose your furniture carefully if you are buying new. If you are reading this before purchasing something, that is great. Most people contact me after they have already brought in furnishings that are offgassing.

It’s a little trickier to deal with after the fact, but there are still some things you can do to promote the offgassing and remove or seal in the VOCs (including formaldehyde) if you can’t return the item or just really want to keep it.

The article goes through ways to seal, encase, and promote offgassing of VOCs.

This post contains affiliate links. Upon purchase, I earn a small commission at no extra cost to you.

Make Sure you do the Following Before Purchasing:

1. Material Make Up – Find out it is made of exactly (if it says engineered wood or other wood we need to know what that is). Same goes for paints and coatings.
2. Return Policy – Find out if it is returnable and what are the policies, do you pay for a return, is it feasible that you can physically return it. Along these lines – don’t assemble it before you know it’s going to be OK for you.
3. One Thing at a Time – Only buy one new piece of furniture at a time if you are very sensitive to VOCs.
4. Spare Room for Offgassing – Figure out if there is somewhere to set this aside if the offgassing is too high for you – a spare room, a garage, basement or sunroom – depending on the item. If you are super sensitive to VOCs then you want the space to be disconnected from the rest of your living space in terms of airflow.
5. Barriers to Encase it – Have barrier materials on hand if we suspect you will need them and do not have the ability to return or isolate the item in another room – plastic sheets, foil, and or charcoal blankets.
6. Sealants on Hand – Have sealants ready if we expect you will need to seal up some of the offgassing. Don’t assemble the furniture before sealing (ideally).
7. Contact Me before buying furniture to determine the potential for offgassing – we can find out what it is made of, how to get you samples of those raw materials, and make a plan to deal with the offgassing if it’s unavoidable.

If you have Already Purchased Furniture that is Offgassing Here are Some Steps to Reduce it (and Speed it Up)

1. Use Air Flow and Heat – Before assembling the furniture (ideally) take it somewhere to promote offgassing. Use airflow and heat to speed up the outgassing of chemicals from the materials. You can take it outside (though make sure it doesn’t get too humid and know that UV can discolor many materials (especially fabrics) but can also help promote offgassing), you can put it in a spare room that is as warm as you can make it, or you can simply increase airflow in your house. The main way that materials outgas is heat, air and time so help this along before moving on to the next steps if you can.
2. Use Extractor Cleaning – to help remove topical fabric treatments on upholstered items.
3. Encase it if Necessary – if you do not have a safe space to promote offgassing and cannot seal it fast enough, use temporary encasements to sequester the offgassing. You can use plastic sheets, foil, foil-backed tarps, Mylar, or activated carbon cloth and wrap it around the furniture to block offgassing. The post on encasing provides links to all those materials and lists them from least to most effective. You may need to use tape to seal it more completely, depending on the item and how bothersome it is.
4. Use Sealants – use special sealants to seal in offgassing more permanently. These can work on almost every material from vinyl, other plastics, rubber, wood, engineered wood, etc. Shellac is my go-to sealant because it works on almost every material and is usually the best seal. Though it is shiny and may not be your desired look. It can be removed later with alcohol off of many materials. There are also specialty water-based sealants like AFM Hardseal, AFM Safeseal for wood products that offgas formaldehyde. AFM Poly BP and AFM Acralacq are two other clear sealants that can work on some wood products. In some cases, paint could be used on top of or below another sealant. A more detailed look at sealants is outlined in this post. You can also contact me here for more help.
5. Use Sorbent Materials – you can also use materials that absorb (or adsorb) VOCs such as formaldehyde. This could help in a few situations, but especially if you are going to encase something or if you have something locked up in a small space to offgas it. You can use charcoal or zeolite, and you can also use powders/granules on the item – like zeolite, baking soda, or cat litter as long as you can remove that easily later. You can also use an air purifier made for offgassing in the room but this will usually only help the air in the room – it could help to stop VOCs from reabsorbing into other materials nearby, but I prefer airflow as the solution.
6. Ozone – ozone machines can help promote offgassing in some items but it often backfires, creating worse compounds, doesn’t work, or breaks materials down, so I’m not keen to recommend ozone unless you know it works for you and that material.

Strategies by Furniture Type:

How to Offgas a New Bed Frame

If you bought a new bed frame that has an odor and is offgassing, find out what it’s made of exactly.

Many bed frames have some engineered wood in them (that offgas formaldehyde), look at the stains that might have been used (oil-based wood stains do offgas a fair bit), and if it has upholstery, that is likely polyurethane (which offgasses a little bit, but not that much).

To remove offgassing you can start with using airflow and heat and you can cover it if necessary – even if it’s temporary.

For wood sealants and formaldehyde from engineered wood, sealants can be used to block that offgassing. Shellac works over these surfaces to block the formaldehyde and VOCs from stains but it does leave it shiny. Any hidden areas can be sealed with shellac easily.

For wood that is in view – you will want to find out if it’s an oil or water-based finish on the wood and then consider the options for sealants.

How to Offgas a New Mattress

Most mattresses need a little bit of time, heat and air to become tolerable especially for the chemically sensitive.

You want to test materials before buying a mattress since there is no one best material here – cotton, hemp, wool, latex, and foam could all work, or not work, for sensitive folks.

Memory foam takes the longest to offgas of the foams and I like to avoid that one – that may take too long for any of these strategies to work. Natural latex also is very slow to offgas that natural odor (natural VOCs).

The first step is still going back and finding out exactly what it in the mattress. Then I would still provide space for it to air out, and you can cover it with an activated carbon cloth which can absorb but not totally block the progress of outgassing it.

If necessary you can go further and wrap it in plastic or foil. I would provide some sorbent materials underneath if you do that and are trying to save it.

How to Offgas a New Couch

New sofas are particularly difficult to offgas because of the size.

Like with other furniture you want to look a close look at what is in it. Some sofas have solid wood inside, others have plywood (which only offgasses very slightly) and some have particleboard which offgasses more formaldehyde.

There is nothing you can do to remove the formaldehyde inside the wood components other than to use air, heat, and time. And of course, you could encase the whole sofa if necessary with materials that sequester offgassing.

The cushions often have polyurethane foam which has some VOC offgassing, with memory foam being the highest offgasser. Other parts of the cushioning likely have polyester which has very low offgassing.

You can add sorbent materials onto the sofa while you give it time.

If you are bothered by the topical treatments on the fabric you can use extractor cleaning to help that along.

How to Offgas Cabinets and Shelving

With cabinets and shelving from big box stores it’s often not obvious online what exactly it is made from. A combination of engineered wood and solid wood, most likely.

Kitchen cabinets are often particleboard surrounded by laminate/melamine, which blocks the offgassing of the formaldehyde inside, but edges are often exposed. You should find and seal raw particleboard edges with a few coats of shellac (or from Walmart if that link is down) or Safeseal.

In better quality cabinets you will find plywood boxes (which have extremely little offgassing) and even solid wood door fronts and drawers.

A more difficult material is MDF. It’s higher in offgassing (formaldehyde) than other pressed wood products and if it’s on the drawer and door fronts it’s often too difficult to seal that up in a satisfactory way that will still look good.

You can ask about the paint/lacquer type but it’s very likely that you need to see the product to know what the real life offgassing is like. I don’t often find these coatings are high in offgassing. But if they are you can air them out first and try painting over it with a combo of shellac and paint to seal in the offgassing, if that won’t ruin the look.

The backing might be high-density fibreboard (HDF) which is easy to seal because it’s not visible on the back. Seal it with shellac (from Amazon or Walmart) or AFM Safeseal.

Putting carbon sachets and zeolite granules in the cabinets will help absorb the offgassing and stop the almost never-ending cycle of the formaldehyde reabsorbing. When I inspect cabinets for offgassing, it’s always the inside that still smells new years later. You could alternatively leave the doors open, at least at night, to promote offgassing.

How to Offgas a Dresser, Armour or Media Console

Like some of the other furniture above, figuring out exactly what a dresser is made of online is not always easy or possible. Still, try to find out which engineered wood products are used so that you can assess the offgassing potential and figure out how to seal them.

Before assembling furniture I would first set it aside to offgas it with heat, air and time. Then you can make a plan to seal it.

You likely don’t want to have to seal the visible sides of a dresser though, as that would entail refinishing the whole thing.

So it’s best to look for solid wood all around. The backing and drawer bottoms might not be solid wood and that’s probably OK, as those areas are easier to seal with shellac or the sealer of your choice.

You can of course, in an urgent situation, wrap the whole thing up in plastic or activated carbon fabric. If you do that with the intention of saving it, put some carbon baggies and zeolite in the drawers so that the offgassing does not just reabsorb.

Corinne Segura is a Building Biologist Practitioner with 7 years of experience helping others create healthy homes.

Did you find this post helpful? If so you can buy me a coffee to support the research behind this blog. Thank you!