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.
Phoenix