Solution for Polyurethane Topper that's Off-gassing?

I recently bought a 3-inch polyurethane topper to help with pressure points and it works great. My problem is that if I lay on my stomach with my face against the mattress, the chemical smell is unbearable. It’s not a huge issue for me because I’m a side sleeper with my head on a pillow. But my husband sometimes sleeps on his belly so it is a problem for him.

I’ve had the foam for 2 nights now and I have it positioned under the mattress pad and a mattress cover but that doesn’t block the odor. I also let the foam air out for 12 hours one day with nothing on it, but that didn’t help either.

Does anyone know if there is a completely enclosed case that will contain the polyurethane gas or if there is another solution? I’ve read of people with memory foam mattresses that say the odor fades in a few days but I’m not sure if this will be the case with regular polyurethane foam. I know this type of foam is usually used within a mattress–I am using it in a different manner by having it as my topper. I plan to call the mattress factory and talk to the man who sold me the foam but wondered if anyone had any input for me here.

Thank you and sweet dreams, everyone.

Hi Karla,

I use this encasement (there are different sizes available.) When it is on my latex mattress I can’t smell the latex anymore. However, the latex smell is not very strong, so I don’t know if it would work in your case.

Hi karlabennett,

Most polyurethane foam will offgass for a period of time although memory foam usually has a more noticeable smell than polyfoam. It is part of the “new car” type of smell that is common with any polyurethane foam product. There is also a lot of variance in how long it will last and while it is usually noticeable for anywhere from a few days to a week or two … in some cases it can last longer.

Many of the VOC’s that people react to have no odor (such as TDI compounds) while many others do (such as aldehydes and amines or other catalysts). The degree of any toxicity is not connected to the degree of smell however so what someone may smell may not be the cause of any reactions to the foam and some people may react to compounds that produce no smell. Most foam companies keep the foam in ventilated warehouses for a while to air it out but in some cases the foam is used more quickly than others and in some cases the foam (or topper or mattress etc) may have been wrapped in plastic for a long period of time and the smell has accumulated.

If a mattress uses polyfoam or memory foam that is CertiPUR certified then at least you have some assurance that any initial smell isn’t harmful.

If it is only the smell you are concerned with there are a few things you can do to hasten the process.

  1. Walk evenly over the surface of the foam break open any cell windows that are still closed in the foam. Some companies pre-compress the foam and then sell it as a “benefit” (such as Simmons “transflexion technology”).

  2. Remove any bedding over the mattress during the day and leave your bed “unmade”.

  3. Keep the windows open and make sure there is good air circulation in the room. A fan on one side of the bed that points to an open window on the other helps. Putting the mattress on its side with a fan at the end can help air reach both sides of the mattress but I wouldn’t be cautious about doing this for an extended period of time (days) because in some cases the layers may shift and it’s best for a mattress to lie flat for longer periods of time.

  4. Keep a bowl of vinegar near the mattress (say on a bedside table) and in the path of the airflow out of the room.

  5. Products made with Zeolite (such as here) can also help absorb VOC’s and odors (again in the path of the VOC containing airflow is best).

  6. An air purifier that can absorb VOC’s can help.

  7. Fabreeze can mask the smell while it dissipates over time.

  8. Lower the humidity level of the room (higher humidity can increase the problem).

  9. An activated carbon “blanket” such as these may be helpful and can absorb the VOC’s and smell that comes from a mattress.

  10. In the worst case … 5 - 6 mil impermeable polyethylene plastic (transparent and non toxic or “food grade” versions or they may also have the same issue) will help to trap the VOC’s in the mattress. An example is here. Of course this is not really a practical solution for the long term compared to a new mattress that doesn’t offgas in the first place and would be “worst case” only. Other cover materials are still gas permeable and while they may help reduce the smell somewhat and in some cases (as koala mentioned) this is enough to make the process a little less noticeable … they won’t solve the underlying problem.

In some cases a smell that is much stronger or lasts much longer than normal may point to an issue with the formulation or manufacturing of the foam.


Polyurathane and other synthetic materials in mattresses tend to offgass VOCs. Flame retardants are usually added in the US as well. If there is a bothersome smell this is a toxin. That new car smell is a chemical smell.

I write about the most affordable chemical free options.

Hi Segura,

I took a look at your site and you have clearly done some great research which will help many people :slight_smile:

There are a couple of instances though as far as mattress materials that I would question some of the more “absolute” statements you have made. Two in particular …

I’m not sure this is accurate. I for example have real difficulty with the smell of cooked cabbage (strangely enough because my heritage is Dutch/German) and cooked turnips and neither is toxic. In addition to this … many of the most toxic VOC’s may not have any smell at all so while smell can certainly affect people it is not a reliable indicator by itself of toxicity.

This may be “somewhat accurate” but is not “completely accurate”. It may be more reliable to go by testing protocols and certifications that can test for harmful chemicals (which can be released into the air as particulates or dust when the material breaks down) or VOC’s below the detection threshold of most people and by this measure there are blended latex products that contain a mix of SBR (synthetic latex) and NR (natural latex) that are certified by the same standards as all natural latex and by most definitions and experience would be considered completely safe … even for most people with MCS. I think there is a tendency sometimes to make an assumption and “lump” many separate issues or products into a single category or blanket statement which can be less accurate than looking at each issue or material separately. There are also some polyfoams that have been tested by OekoTex (mostly in Europe) for example which also pass the same Oeko-Tex testing protocols. PET (recycled plastic) is another example of a synthetic material that may be useful for people with MCS.

These types of “more synthetic” but “safe” options may give people with MCS a way to use quality materials that are less costly and more widely available and focus on other issues which are far more difficult to avoid (which your site does a great job investigating and explaining).

Thanks again for taking the time to put your site together and for letting us know about it. You really have done a great job.