Last Updated on August 24, 2023
Does Casper Mattress use Fiberglass? Yes, Casper uses fiberglass in its mattress materials. However, it can be hard to sift through the misinformation spread across the internet. Some of the misinformation is spread by a few bad mattress-selling websites, and some of it could even be attributed to Casper itself due to how they answer questions.
Casper was one of the first bed-in-a-box mattress companies almost a decade ago, and it rose in popularity very quickly. However, in 2018, online horror stories of Zinus mattresses leaking fiberglass in peoples’ homes made fiberglass free mattresses a top priority. Soon after that, Casper was under scrutiny for using fiberglass in its mattresses without disclosing it on the tags.
Does it even matter if Casper uses Fiberglass?
Some unwitting owners of fiberglass mattresses noticed skin irritation and decided to find out what was causing the issue. After careful inspection, they found rips and tears in their mattress covers that were accidentally made by pets and children. Closer inspection revealed particles of fiberglass leaking from their mattresses.
Fiberglass shards are easier to see by shining a flashlight on them in a dark room.
Many people would assume a zippered mattress cover is removable, and many fiberglass mattress owners innocently made that assumption. Only after removing the mattress cover for washing did they realize fiberglass particles were being released in large amounts.
A few unlucky fiberglass mattress owners only discovered the fiberglass after their clothes were contaminated with glass fibers from their washing machine that were deposited by the mattress cover.
Fiberglass Use in Casper Mattresses can be Confusing
People on Reddit, Youtube, and TikTok say their Casper mattresses are leaking fiberglass-like particles from the firesock. But Casper’s website, and Amazon listings for Casper mattresses, state the Casper firesock is made from “Silica Thread”. Surely Casper isn’t lying, right? Correct, technically speaking.
Put simply, the confusion is all just semantics. Are Casper firesocks made from Silica thread? Sure, but fiberglass is made by combining a large portion of silica with smaller amounts of other ingredients within a resin. So Fiberglass technically is a “Silica thread” in a broad sense.
So, does Casper have Fiberglass or Not?
Yes, Casper mattresses have fiberglass. I asked Casper plainly if its Silica firesock was just fiberglass by another name and Casper confirmed its silica thread is just fiberglass.
Yes, Casper definitely uses Fiberglass in its Mattresses
When I asked plainly, Casper told me flat-out that its firesocks contain fiberglass. This is an exact quote of what the Casper associate said to me in chat:
“Yes. The firesock is composed of an inherently fire resistant (FR) rayon yarn with a fiberglass core, blended with small amounts of polyester and modacrylic.”
Fiberglass Free Memory Foam and Hybrid Alternatives to Casper
Below are my recommendations for the best Casper mattress alternatives that don’t contain fiberglass. However, I also maintain a big list of mattress brands without fiberglass that is useful at the start of shopping for a bed without fiberglass. I’ve also written a guide for buying mattresses on Amazon without fiberglass as well as a guide for organic mattresses.
How are Casper Mattresses Constructed?
Casper manufactures multiple models of mattresses, but they all fall into two main categories – memory foam mattresses, and hybrid mattresses. Let’s take a look at how Casper Mattresses are made from the bottom to the top.
Summary of Casper Mattress Construction:
- Hard Foam Base Layer – Casper Original memory foam mattresses begin with an initial thick base layer of polyurethane foam, equal to more than half the overall height of the mattress. Hybrid Casper mattresses have a thinner base layer of foam with walls that rise up to provide edge support around the coil springs.
- Coil Layer – Hybrid Casper mattresses have a layer of coils on top of the base layer.
- Medium Foam “Zone Max/Pro” Support Layers – The Wave Hybrid Casper mattresses have a third layer of medium firm polyurethane support foam with gel pods that are supposed to give proper contouring to the butt and lower back of back sleepers. The Casper Nova mattress used a different zone support layer without gel pods.
- Medium Foam “Zone” Support Layers – Most Hybrid Casper mattresses aside from the Wave/Nova line have a third layer of polyurethane support foam that conforms to the hips and shoulders for side sleepers – this is the 4th layer in the Wave/Nova lines of mattresses.
- Soft “Air” Foam Comfort Layers – After the support foam layers, Casper mattresses use a soft perforated polyurethane air foam for comfort and pressure point relief.
- Cooling “Air” Foam Comfort Layers – The Wave and Nova lines of Casper Mattresses also have an additional perforated viscoelastic memory foam layer that is supposed to provide additional comfort as well as a cooler sleep.
- Flame Retardant Fire Sock – Around all of the Base, Coil, Support, and Comfort layers is a fire-resistant cover known in the mattress industry as a “firesock”. The firesock is where the fiberglass is used in a Casper mattress.
- Non-Removable Cover – Surrounding all of the foam layers and the firesock is an outer mattress cover made from It’s made of Polyester derived from recyvled PET bottles, upcycled cotton, rayon, and lycra.
Actual conversation with Casper about Fiberglass
Me: I see people on amazon and reddit complaining about their casper mattresses leaking thread-like particles, are those particles fiberglass? Casper states flammability tests are met with just silica
Casper: I wouldn’t know if it was fiberglass that was leaking from their mattresses, some of our mattresses does not have fiberglass
Me: so some of Casper’s mattresses do use fiberglass?
Casper: Yes. The firesock is composed of an inherently fire resistant (FR) rayon yarn with a fiberglass core, blended with small amounts of polyester and modacrylic. The fiberglass is fully encapsulated in the FR Rayon fiber, so no fiberglass should be exposed. In the event of a fire, these fibers are designed to char and form a barrier over the foam, preventing the flame from spreading into the foam layers.
Frequently Asked Questions
John started JSnowCreations as a place to post random tech guides and product reviews. However, while shopping for his daughter’s first “big girl” bed in 2019 he learned about the hidden dangers of fiberglass in mattresses. Since then, John has made it his mission to expose as much hidden fiberglass in mattresses as possible. His ultimate goal is federal regulations that ban fiberglass from being used in mattresses, or at least a law that require it to be listed in the material tags.