Polyurethane Foam - which type offgasses least?
Dec 5, 2011 10:33 PM
Joined: Dec 5, 2011
Points: 7
Hi,

 

Because of chemical-sensitivity issues, I am not all that thrilled at all about buying a mattress with polyurethane foam, or purchasing a foam component to build my "sleep system" - but for ergonomic reasons, I may have no choice (yes, I've tried the supposedly "healthier" latex - it didn't work out).  So I wanted to ask this forum - what properties should I look for in foam that would minimize my exposure to offgassing substances and toxic flame retardants?

Is it true that the softer (in ILD) the foam is, the more it offgasses - or is the opposite true?  What about densitity - how does increasing densitiy affect the amount of offgassing?  Are there certain types/brands of foam that are known to offgass less than others?  Does the amount of flame-retardant used in the foam vary with firmness-level and/or densitiy? 

While I'm at it - I might as well ask if anyone knows of any particular brand of mattress that has little-to-no offgassing?  Which would be the lesser of the evils as far as this is concerned?  (My budget is quite limited - I cannot spend more than $800 on this mattress.)

Thanks for any feedback...

Re: Polyurethane Foam - which type offgasses least?
Reply #1 Dec 7, 2011 2:51 PM
Joined: Aug 30, 2011
Points: 55
fumesallnight wrote:

Hi,

 

 

Because of chemical-sensitivity issues, I am not all that thrilled at all about buying a mattress with polyurethane foam, or purchasing a foam component to build my "sleep system" - but for ergonomic reasons, I may have no choice (yes, I've tried the supposedly "healthier" latex - it didn't work out).  So I wanted to ask this forum - what properties should I look for in foam that would minimize my exposure to offgassing substances and toxic flame retardants?

Is it true that the softer (in ILD) the foam is, the more it offgasses - or is the opposite true?  What about densitity - how does increasing densitiy affect the amount of offgassing?  Are there certain types/brands of foam that are known to offgass less than others?  Does the amount of flame-retardant used in the foam vary with firmness-level and/or densitiy? 

While I'm at it - I might as well ask if anyone knows of any particular brand of mattress that has little-to-no offgassing?  Which would be the lesser of the evils as far as this is concerned?  (My budget is quite limited - I cannot spend more than $800 on this mattress.)

Thanks for any feedback...


The higher the density of the foam the longer it takes to air out and the ILD will not have an affect on this. The longer the mattress stays in the warehouse the less odor you will have. So if you have a high density foam mattress and they order it from the manufacture and ship it to you. than you will will have a pretty strong odor for a while. It isnt really the flame retardants that will be off gassing as much as the chemicals used in manufaturing memory foam. The flame Retardants are usually odorless.

I was going to suggest latex, but your price range will only provide you with synthetic latex which is closer to poly foams and so you should stick with getting a better poly foam then the synthetic latex.

It is going to be a bit of a trade of as the higher the density the greater the durabilty of the mattress, but also the greater the smell. You can reduce this by seeing if the retailer has the mattress in stock. If they do then most likely it has been in the warehouse long enough to reduce or eliminate the odor. If they have to order the mattress form the manufacture then it will have a strong odor when it first arrives, so you could have them order it and then wait a week or so to accept delivery.

Re: Polyurethane Foam - which type offgasses least?
Reply #2 Dec 11, 2011 6:44 PM
Joined: Nov 19, 2011
Points: 76
DaveStro wrote:

 


The higher the density of the foam the longer it takes to air out and the ILD will not have an affect on this. The longer the mattress stays in the warehouse the less odor you will have. So if you have a high density foam mattress and they order it from the manufacture and ship it to you. than you will will have a pretty strong odor for a while. It isnt really the flame retardants that will be off gassing as much as the chemicals used in manufaturing memory foam. The flame Retardants are usually odorless.

I was going to suggest latex, but your price range will only provide you with synthetic latex which is closer to poly foams and so you should stick with getting a better poly foam then the synthetic latex.

It is going to be a bit of a trade of as the higher the density the greater the durabilty of the mattress, but also the greater the smell. You can reduce this by seeing if the retailer has the mattress in stock. If they do then most likely it has been in the warehouse long enough to reduce or eliminate the odor. If they have to order the mattress form the manufacture then it will have a strong odor when it first arrives, so you could have them order it and then wait a week or so to accept delivery.


True, except for how long it sits in the warehouse... most mattresses are manufactureds and put into hermetically sealed bags that will not allow the mattress to off gas properly. There are several methods to help reduce the intensity overall. (Most companies in the top 10-15 brands are using components that are fire retardant--like kevlar, rather than any chemicals)

  • One company (Simmons) uses a process called "transflexion" which is a fancy name for the process of compressing the foam down to the the thinnest possible compression to squeeze out any trapped air/gasses/smells... the process is done three times
  • Tempurpedic does a similar process one time with their Tempur material... while the density is similar to other memory foams, it is (seemingly) a more durable product and I usually encourage my clients to use the next tip to help them
  • As soon as you receive your mattress (and season/time allows) walk on your mattress in an even pattern from head to toe and from side to side... a complete pass will help "crack" or open any foam cells that may still be holding onto the smells, it will also help make it feel more like the model you tried in the store... doing this 3-5 times (more if you are very sensitive) can help the transition very easily
  • Ask your retailer to open the mattress for you... walk on it themselves (no shoes smiley)... wrap it back up and deliver it later allowing the majority of the smell to remain in the store
  • While you are gone from home, open the windows, pull back your covers/sheets/mattress pads/water-proof protectors, etc. and allow to breathe with a fan one one side pointing towards the window on the other side of the bed

Bottom line is, all new mattress (DIY or manufactured) will have that "new car smell" and how you condition your new mattress will help determine the result and how quickly your desired result is reached

P.S. - with an $800 budget, you may want to consider some variation of coil and specialty foam reducing the cost and the amount of foam needing to be aired out. not sure what size you are looking at either which can dramatically change your options at that price.


Re: Polyurethane Foam - which type offgasses least?
Reply #3 Dec 12, 2011 6:22 AM
Joined: Dec 5, 2011
Points: 7
Thanks guys for the feedback.  Yeah - about synthetic/blended latex - I learned the hard way that it's apparently as bad, perhaps worse, than "conventional" foam - at least for me.  It was a highly disappointing experience - since all of the propaganda on latex mattresses somehow led me to believe that there wouldn't be those problems.  I somehow thought that the latex would be a stable material that wouldn't offgass - boy, was I wrong.  It was quite unsettling to discover that the odor was similar to gasoline (even "non-sensitive" family members noticed the gasoline-like odor permeating from the boxes when we packed the latex layers back up to return them).  

What's more - I think that latex may be worse than conventional foam in some ways - in that it seems to be a less stable material that, in the ever-continuous process of breaking down, releases odors/fumes idefinitely.  There seemed to be no end to the offgassing - whereas with conventional foam, the offgassing period may be more finite.

I had thought/hoped that "100%" natural latex might be a better option - perhaps a 100% natural Dunlop latex (Dunlop might be a little more stable and offgass less than Talalay).  But after exploring that option just a little bit - I'm not so sure.  All latex seems to break down "slowly" - the process can be slowed, but it cannot be stopped.  Conventional foam may break down some - but not in the complete way that latex does.  It seems that I might not react well to the fumes of even natural latex - I think even natural rubber is an aromatic hydrocarbon.  Just because it is "natural" doesn't mean that it's healthy for all (although it is probably healthier than synthetic latex).  

As for the flame retardants - flame retardants may have a less-obvious/non-existent smell - but I still want to steer clear of them as much as possible.  I don't think my chemical sensitivity is restricted to just odoriferous/offgassing substances.  And is it certain that - just because there is no detectable odor, that there is no offgassing?  Whatever the case, whether it be via offgassing, passive diffusion, or whatever - there seems to be evidence that flame-retardant materials somehow wind up in the human body.  Recently, I received a personal indication of this; the results of a hair-mineral test showed relatively high levels of antimony (which I've read is a common fire-retardant component).    

I started down this exasperating path because I felt the need to get rid of my very old innerspring mattress - which somehow started giving me bothersome symptoms after 20-plus years of no problems.  There were no foam components in the mattress, so I attributed my symptoms to electromagnetic hypersensitivity exacerbated by the innersprings.  I had thought that a metal-free mattress would be the solution - but the latex mattress certainly didn't work out, and at this point I'm extremely leery of mattresses made entirely of conventional foam.  I strongly considered buying a mattress made entirely of cotton and/or wool - but I determined that it wouldn't work for ergonomic reasons.  So I'm basically forced to "pick my poison", so to speak.  What mattress would be the lesser of the evils for me?

It seems that all innerspring mattresses manufatured these days have at least a little foam in them.  And for ergonomic reasons, it is possible/probable that I will need at least a little foam.  Am I better off purchasing the most comfortable innerspring mattress possible (which would include a signficant foam top layer) - or purchasing an innerspring bed with the least amount of foam possible, and adding a foam layer from an independet source?  Which option would be better for my chemical sensitivity?

There might be pros and cons to each.  One thing that concerns me about the second option is that there seems to be only a few places selling "regular" polyurethane foam layers these days - the overwhelming majority of foam layers on the market seems to be the more chemically-intense viscoelastic memory foam (which I want to avoid).  This is a disturbing trend: a few years down the road, one might not be able to get regular polyurethane foam anywhere.

Oh, and the bed I purchase will be full-sized - in case that makes it easier to narrow down viable possibilities that would be within my budget.

Sorry for the length - but perhaps this explains my dilemma a little better.

Re: Polyurethane Foam - which type offgasses least?
Reply #4 Dec 12, 2011 2:43 PM
Joined: Dec 17, 2009
Points: 850
That is quite the pickle.  Natural rubber does indeed have an odour; and all polymer materials break down over time including polyurethane...  Technically...even steel outgases...just slower than polymers do.  What matters is the toxicity...natural rubber is harmless...but of course if you are really sensitive to smells than even odour (even if it is harmless) might cause you issues.  You may want to consider a coil mattress with nothing but cotton in it.  Vivetique seems to be one of the more reasonably priced...there is another...but my mind is drawing a blank right now.  
Re: Polyurethane Foam - which type offgasses least?
Reply #5 Dec 14, 2011 8:33 AM
Joined: Dec 5, 2011
Points: 7
budgy wrote:

 

 

That is quite the pickle.  Natural rubber does indeed have an odour; and all polymer materials break down over time including polyurethane...  Technically...even steel outgases...just slower than polymers do.  What matters is the toxicity...natural rubber is harmless...but of course if you are really sensitive to smells than even odour (even if it is harmless) might cause you issues.  You may want to consider a coil mattress with nothing but cotton in it.  Vivetique seems to be one of the more reasonably priced...there is another...but my mind is drawing a blank right now.  

I'm a little confused about polyurethane foam:  on the one hand, they say that it's not biodegradable and will persist in the environment idefinitely.  On the other hand, foam is known to soften over time - which seems to be indicative of some kind of long-term "breaking down" process.  Does foam eventually break down to the point of no longer being a solid unit - ala latex?  Does the process of "softening" release volatile substances (or put another way:  does the act of softening involve offgassing of any sort)?

While I have come to the conclusion that all types of latex seem to be potentially bothersome - I do wonder if I had made the decision to buy a mattress consisting of 100% natual Dunlop latex - instead of the partially-synthetic Talalay latex mattress that I did buy - would that mattress have been more tolerable.  While I do have some experience with 100% natural latex samples that reveals that it also has a persistent odor and might be bothersome - my observations of 100% natual latex might be slightly clouded by my horrible experience with the synthetic Talalay.  I'm less willing to go through the whole process of trying out and possibly returning another latex mattress (a process that also drains funds).  I've already wasted enough money.  

The odors of both types of latex were so permeable that my clothes often seemed to reek of the odor - that is no way to spend one-third of your life.  

And I believe I've read that even 100% natural latex is an aromatic hydrocarbon - a substance that can give people with chemical sensitivities quite a bit of trouble.  Also, there might be certain additives and/or flame retardants within the latex that are bothersome.

I wish I had been better informed so I could have avoided the decision to buy the synthetic Talalay mattress - but information regarding the constituents and the properties of these mattresses is hard to come by, to say the very least.  There is a lot of seductive material on the web about latex mattresses that hypes all kinds of alleged positive qualites (i.e. it's supposed low-toxicity, it's antimicrobial qualities) - information revealing the downsides of latex is scant at best.  It was only after I bought the mattress and was experiencing problems with it that I did some digging and learned that styrene - a component of the styrene-butadiene rubber used in synthetic latex - is a probable human carcinogen.  

I am fairly health-conscious, which makes me feel all the more foolish for failing to forsee that there would be those problems with synthetic (and possibly natural) latex.  I was hoodwinked by the propaganda.  It's not like these companies are forthcoming with the fact that their product smells like gasoline, or continuously offgasses volatile substances that have gasoline-like odors - although they should be.

 

 

 

P.S. - just wanted to add that it is the synthetic latex that smells like gasoline - not necessarily the 100% natural latex.  From my limited experience with 100% natural latex, it has more of a pure-rubber smell, which would give one the idea that it is less toxic (whether that is actually true or not).  I don't want to condemn all types of latex as having that odor - although as I said above, even the 100% natural latex could potentially be problematic.
 

This message was modified Dec 14, 2011 by fumesallnight
Re: Polyurethane Foam - which type offgasses least?
Reply #6 Dec 14, 2011 8:46 AM
Joined: Dec 5, 2011
Points: 7
budgy wrote:

 

That is quite the pickle.  Natural rubber does indeed have an odour; and all polymer materials break down over time including polyurethane...  Technically...even steel outgases...just slower than polymers do.  What matters is the toxicity...natural rubber is harmless...but of course if you are really sensitive to smells than even odour (even if it is harmless) might cause you issues.  You may want to consider a coil mattress with nothing but cotton in it.  Vivetique seems to be one of the more reasonably priced...there is another...but my mind is drawing a blank right now.  


Sorry - my posts are so long that I feel the need to make multiple posts out of them - but I was on the Vivetique website and from what I saw, there were no published prices on their products.  That is often a bad sign that the prices are sky high.

The only "mass market" mattress that I've seen that appears like it might contain no foam is a Sealy mattress sold on the Sears website.  I first came across it several weeks ago - then, when I returned to the website, I was disheartened to see that the price of this mattress seemed to spike to twice as much as it was when I first viewed the page.  (I hate these pricing games.)  Based on the overall market - paying over $500 for a basic, "bare bones" mattress that contains no foam layers seems excessive (and that $500 is for the mattress alone - the foundation is an additional $200 - $300).

Considering that you can pay less for "plusher", more layered mattresses - is this worth $522?

http://www.sears.com/shc/s/p_10153_12605_08212678000P?blockNo=51&blockType=G51&prdNo=1&i_cntr=1323845968552

 



 

This message was modified Dec 14, 2011 by fumesallnight
Re: Polyurethane Foam - which type offgasses least?
Reply #8 Dec 14, 2011 3:08 PM
Joined: Dec 17, 2009
Points: 850
Talking about various types of breakdown and decay of polyurethane foam versus synthetic latex (SBR) and natural latex (NR).  Things are a little different. 

It is true that in a landfill we have no idea how long polyfoam will stay around for, it does not readily bio-degrade.  So this process could take hundreds or even thousands of years. SBR is somewhat similar as well, it does not readily biodegrade, although because it is not plastics based it might break down a little quicker.  Natural rubber would break down pretty quickly in comparison.  

WIth regards to breakdown from functional use in a mattress, natural rubber or even synthetic latex lasts a lot longer than polyurethane based foams.  Polyurethane  softens a lot from use, this is loosely related at best to the chemical off-gassing component, and has more to do with the cell structure of the foam simply being more brittle and less elastic than natural rubber.  

With regards to the various types of odours and what really causes them.  With polyurethane foams a lot of people assume that chemical off-gasing is somehow a temporary thing; this is because the odours are always much stronger when the mattress is brand new and will dissipate with time. In truth the off-gasing is indefinite, the product does break down over time, as all polymers do. Most of the chemicals released over time are odourless, or are odourless below a certain concentration.  For instance formaldehyde below something like 20 ppm (parts per million) is usually undetectable.  Above that, it can have a pretty powerful odour to some people.  

Synthetic latex does have a distinctive chemical type smell to it, I would say less so than polyurethane foam...I do not mean to be argumentative because obviously what you experienced was very real to you...but I would not describe it like gasoline.  Gasoline is an incredibly powerful and offensive smell...realistically if the beds smelled like that no one would buy them after laying on them...in any event some people are much more sensitive then others when it comes to these things. 

Natural rubber has a smell that by definition will never go away because its not some kind of chemical additive that causes it...its the natural smell of hevea milk.  It may be very noticeable to some individuals, and not so much to others. But for instance if you walked into a room full of apples....you could smell the apples.  

The reason I suggest cotton filled mattress...is that cotton is relatively odourless as well as non-toxic...its one of the only materials in the world I could list that fits both of those criteria. 

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