Silica safety

Hi, I’ve searched the site and forum and can’t find any detailed discussion about the safety of rayon/silica products to meet flammability regulations.

Does anyone know whether there is any indication the silica can become airborne? And if so, are the particles large enough that an allergy barrier will contain them?

Amanda

Hi wmorris,

There is a mention here of the rayon/silica fire barriers.

This seemingly brief few paragraphs was actually the conclusion of many hours of research into fire retardant materials and for those who go in this direction … it quickly becomes clear that there is a huge amount of misinformation on the web about fire retardancy and all the different methods used to accomplish it. Just a brief synopsis to help with ideas for google searches for those who want to do their own research as well …

Silica (silicone dioxide) comes in several forms … but the two main ones are amorphous and crystalline. The crystalline form is the one which is of concern for silicosis. The amorphous form is of low toxicity Fire Retardants ~ Amorphous Silica safety.pdf (198.6 KB)
even when inhaled. In addition to this … the fire retardant materials such as Visil (which uses sandoflam 5060) and Milliken’sPaladin (trade names) Fire Retardants ~ PALADIN nonwovens sep 2011.pdf uses silicic acid (or polysilicic acid) which is actually mixed in with the viscose and its precipitate becomes an integral part of the fiber itself rather than a “powder” that is added to it. This is why it is called inherent and it is actually a cellulose-polysilicic acid hybrid fiber.

I find it somewhat ironic that some of the “natural” community who confuse the dangers of amorphous silica and crystalline silica also would advocate for the use or more natural pesticides such as diatomaceous earth which is actually a partly crystalline version of silica and carries a far higher risk than the inherent fibers in a mattress.

While I am no fan of the fire regulations or of many of the chemicals used (some of which are no longer used) … I also believe that sites such as the Strobel site which presents some completely inaccurate and misleading information about some of the better and safer fire retardant methods (such as wool and silica) are also responsible for much of the confusion regarding fire retardant issues.

IMO … I wouldn’t hesitate to use either wool or rayon/silica for a fire barrier in a mattress without any worry of danger or toxicity.

Phoenix

I have been talking to intellibed and they offered to recover a demo model and eliminate the silica flame retardant layer for me. Is this really significant? All things being equal I would probably opt for a new one, but this one was only used 4 days and they will recover it and eliminate the silica/yarn layer. I’m also wondering if the yarn layer is polyester, which also has problems.

In the FAQs on the Intellibed website, the company identifies its FR barrier as “A silica based fire blocker with a modacrylic fiber and no bio available chemicals. It basically goes on the bed like a sock.” The silica is the amorphous form Phoenix referred to back in 2012. The FR solution is classified as an inherent version as the silica is added in the fiber manufacturing process so the material becomes a form similar to the cellulose-polysilicic acid hybrid fiber that Phoenix identified. The “FR Sock” that intellibed describes is the most commonly used FR barrier in the US mattress industry. This fabric sock material allows for mattresses with components that have lower levels of “flammability” to comply with 16 CFR 1633. As an inherent solution, it poses no health risk. Suppliers of FR barrier materials to the US mattress industry have made significant advances in their material technologies over the past 10 years, reducing costs and improving the safety and health benefits.

The question you need to ask intellibed is “What will the FR solution be ?” that will be used if they eliminate the FR sock from your demo model. They are required by law to sell you a mattress that meets the CPSC FR standards (provided you are in the US).

The yarn is most likely a viscose rayon or an acrylic.

Hi Luma Sleep,

From what I’ve read and researched, it seems modacrylic has become a “dirty” term in the industry and isn’t considered very “healthy” in general as it normally contains antimony at the very least. I’d be interested to get your insights on it and was also wondering if many of the inherent socks use it, though perhaps leave the term out and just mention inherent rayon and/or silica.

Thanks,
Manimal

So there isn’t really an issue with this type of barrier “flaking off” or becoming airborne in terms of how its made? and probably no more than any other type of furniture fibers? Just curious. It does seem like this, beside wool, is a good option.

We recently had a mattress with fiberglass and rayon (which I’m assuming had the silica). I didn’t realize the cover wasn’t to be removed. After thinking back the whole inside of the cover felt like loose fibers, I was in a hasty hurry. We ultimately had fiberglass everywhere with extensive damage. Now we are wondering about the rayon fibers. Do you know what happens to the loose fibers if they were washed and put into a dryer? Does the silica return to dust and potentially respirable crystalline silica dust? We are feeling unsafe in our home After spending thousands on cleaning. Thank you for any insight you may have.

Hi jamalcore2023,

So sorry to hear of your experience with the fiberglass! That sounds quite awful. It’s commonly used as a fire retardant barrier, which is why the cover was not removable - though it sounds like that should have been made clearer by the manufacturer.

Rayon was developed back in the mid 1800’s, and it’s made by extracting the cellulose from wood fiber; there are different types including viscose, modal, and Lyocell. It’s considered environmentally friendly by and large, and it can be made from eucalyptus, oak, birch and beech pulp, for different uses. Rayon is very absorbent, it can be blended with many other fabrics such as wool, silk, cotton, and linen. One the downside, It also has considerably weak elasticity which can be weakened when the fabric gets wet, and is also flammable - and can be damaged by exposure to other chemicals - so not entirely resilient. The rayon yarn in bedding should not ‘shed’ unduly when washed and dried, providing washing instructions are followed.

Other chemicals are used as part of the manufacturing process, depending on which form of rayon you’re talking about, but since Rayon fabrics use what’s called a ‘closed-loop system’ very little of the sodium hydroxide or other chemicals escape into the environment: The cellulose fiber sheets are next put through a spinneret to create long fibers, which can then be used to create rayon garments or other products like bedding and sheets. Some links you may find useful regarding this subject:

On Rayon and it’s environmental ‘friendliness’
Here’s a look at the different types of cellulose fibers used in Rayon production
Wikipedia on cellulose fibers
Dow chemicals on the ‘chelation’ process of Rayon manufacture
Oecotextiles on cellulose fibers
And on eucalyptus fibers specifically

The silicates you refer to would be part of the fiberglass FR barrier - the Rayon yarn itself should not produce any harmful chemical residue…at worst there could be some slight dust from the cellulose used, which should be fine as long as no one in your house has any extreme allergies to wood or plant based particles - but of course for peace of mind you can contact the manufacturer of the bedding to answer any questions about the specific properties or the manufacturing process for your specific item of bedding.

~ Basilio

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I too did some research a while back on flame retardants. Everyone freaks out when they hear the word silica used anywhere in a mattress.

This article speaks to a lot of it, including Visil. Which is actually a registered name brand. Like kleenex for a tissue.

Flame Retardants

I wrote about hydrated silica on a different forum a while ago. People get needless obsessed about hydrated silica amongst other things. I know this thread was not about hydrated silica specifically, but hydrated silica is mentioned a lot in FR conversations in addition to other “silica” derivative products are not harmful as some seem to think.

I mentioned to one group of folks that if they are that worried about hydrated silica, then stop brushing your teeth. As it is the “abrasive” ingredient in tooth paste they put directly in their mouth every day, sometimes up to 3 times a day!

This in no way midigates the risks of a genuine fiberglass exposure issue or the experience of one.

Just another reference to distinguish between harmful and harmless chemistry that Phoenix referenced at the beginning of this thread and Basilio mentioned above.

Thank you for your response. The rayon inside the cover were loose fibers which I didn’t realize until looking back… I’ll attach a picture after I opened the dryer. What I’m wonder is what happens to the rayon/silica after it was washed and dried. Is it possible that the silica because a respirable dust. I cannot find into on how the loose fibers are made and if it’s possible that after getting damaged and tumbled if it turned into airborne dust.

Also, it sounds like it was Visil in our cover that was washed and dried in the dryer.

Hi there. I purchased a memory foam that had a zipper, removed and washed the outside but wasn’t supposed to. I have fiberglass everywhere. I learned that there was a thin batting on the inside cover made of silica and rayon. Do you know what happens with that stuff when it’s gone through the washer and dryer? I’m quite certain I inhaled a ton when cleaning and I have had breathing issues ever since.

Hi Jamalcore2023.

I’ve moved my response from the Personal Message you sent yesterday into this specific forum topic discussing ‘Silica Safety’ in mattresses. This subject has garnered considerable interest over time, and thanks to all the above contributors, we can slowly add and deepen the knowledge in the matter.

In it’s amorphous form silica used for inherent Fire Retardant applications in textiles is relatively harmless, although the break down in smaller particles can irritate the contact areas and lungs. The real problems arise with silica in crystalline form.

You may want to have a look at this article about fiberglass in mattresses. Even though it does not list any solutions for detoxifying once the airborne particles were inhaled, it can give a few clues to watch for and if you should get alarmed. Fiberglass and Other Flame-Resistant Fibers in Mattress Covers - PMC .

As some of the links in my previous posts where retired I’ll provide some alternative sources of information.
Amorphous or inherent fire retardant materials such as Visil (which uses sandoflam 5060) and Milliken’s Paladin Fire Retardants ~ PALADIN nonwovens sep 2011.pdf (1.1 MB) (trade names) uses silicic acid (or polysilicic acid) which is actually mixed in with the viscose and its precipitate becomes an integral part of the fiber itself rather than a “powder” that is added to it. This is why it is called inherent and it is actually a cellulose-polysilicic acid hybrid fiber.

If you are wondering, as I did, if the amorphous form of silica can be turned into the more harmful crystalline form, here is a quote on Researchgate

You can convert amorphous silica to crystalline silica by heating to about 1000°C in air. What you may find is that you form a type of cristobalite that can be referenced in some X-ray Diffraction references, but the literature on this topic is limited.

In practical terms, as your cover & FR seems to be Visil, where silica is mixed with the viscose or rayon and in its amorphous form. The material break down process already started through washing it drying and the process will continue resulting in smaller particulates that through contact and exposure can certainly produce irritation to lungs, skin, and eyes.

All in all I’d remove and replace the cover and thoroughly vacuum with a HEPA filter and ventilate the affected area . HEPA Air Purifiers will certainly help as well with the smaller airborne particles. If you are still experiencing issues breathing I’d certainly get in touch with a medical practitioner and perhaps have a few Oxygen therapy sessions.

Phoenix

We recently had a mattress with fiberglass and rayon (which I’m assuming had the silica). I didn’t realize the cover wasn’t to be removed. After thinking back the whole inside of the cover felt like loose fibers, I was in a hasty hurry. We ultimately had fiberglass everywhere with extensive damage. Now we are wondering about the rayon fibers. Do you know what happens to the loose fibers if they were washed and put into a dryer? Does the silica return to dust and potentially respirable crystalline silica dust? We are feeling unsafe in our home After spending thousands on cleaning. Thank you for any insight you may have.
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Hello again.

Is the rayon ever made with crystalline silica? Here is a picture of the fibers? Do those look like Visil?

Hi Jamalcore2023.

Is the rayon ever made with crystalline silica? Here is a picture of the fibers? Do those look like Visil?

Rayon is not made with crystalline silica to enhance flame retardancy properties. Rayon is a semi-synthetic fiber derived from natural cellulose, usually obtained from wood pulp. As mentioned in previous posts the rayon can be bonded with silica to create an inherent flame retardant material.

Regarding the image of fibers you provided, it is not possible to determine the presence of crystalline silica merely from visual inspection. From your past posts it looks like you have a Simmons Serta Memory Foam mattress. The shredded appearance in the photo indicates a breakdown of material but doesn’t provide information on the specific chemical composition of the cover. Other forum subscribers often report that the big “S” brand names are tight-lipped about the exact composition of their fire barriers. Generally the best way to find out is to contact the manufacturer directly if this info is not provided on the law tag or label of the mattress.

Phoenix