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Mattresses are made of steel coils, polyurethane foam, latex, or natural fibers such as wool and cotton, arranged in layers under a polyester, cotton, bamboo, or TENCEL fabric cover.
The materials inside a mattress affect how well you sleep, whether you breathe in chemicals at night, and what happens to the mattress when you throw it away.
This guide is for people who want to know exactly what is inside a mattress before they buy one.
The different mattress layers are the cover, the comfort layer, the transitional layer, and the support core, in that order from the top down.
A basic innerspring mattress does not have a transitional layer because its padding is stitched straight onto the coils.
Here's an overview of what's inside your mattress.
The comfort layer is the top layer, usually made from foam or latex. The mattress comfort layer contours to your body, providing cushioning and pressure relief.
This layer also often contains natural fibers like silk or wool to add luxury and improve temperature regulation.
The transitional layer is a buffer between the comfort and support core.
It contributes to the overall firmness and deep support of the mattress. Its primary role is to ensure you don't sink too deeply into your mattress.
Materials like responsive polyfoam or denser latex are used in this layer.
The mattress support core is crucial for overall mattress support, shape retention, and durability.
Support cores are typically made of high-density foam, innerspring coils, or a combination of both.
The mattress cover is the outermost layer that protects the inner layers and can add extra comfort, breathability, and aesthetic appeal.
Some covers are designed with zippers for easy removal and cleaning, enhancing the mattress's hygiene and longevity.
Mattress cover materials vary from simple fabrics like polyester to advanced, eco-friendly fabrics like organically sourced cotton and TENCEL.
Mattresses can contain various materials, including coils, memory foam, latex, polyfoam, wool, and cotton.
Some materials have health benefits, but others contain chemicals that can be harmful.
The healthiest mattress materials are organic latex, cotton, wool, or certified non-toxic foam. But popular synthetic materials like memory foam and polyfoam contain added chemicals.
Innerspring mattresses are known for their traditional coil support system.
The coils are typically made of steel. They provide support and influence firmness and longevity.
There are several types of coil systems:
Pros
Cons
Memory foam is a viscoelastic material known for its pressure-relieving properties and ability to contour your body.
It is based on polyurethane (which is made from fossil fuels) with added chemicals to make it denser.
Initially developed by NASA, memory foam adapts to body heat and weight, resulting in a personalized sleep experience.
Pros
Cons
If you are concerned about the chemical content of memory foam, read our guide to memory foam safety and toxicity.
Latex comes from the sap of rubber trees and is highly valued for its robustness.
There are three main types:
There are also two main styles:
Find out more in our complete guide: What is a latex mattress?
Pros
Cons
Polyfoam, or polyurethane foam, is a versatile material often used in mattress layers (usually in base layers for support and top layers for comfort).
It's less dense and less expensive than memory foam, making it a popular choice in budget mattresses.
It's not as contouring as a memory foam mattress but still offers decent support and comfort levels.
Pros
Cons
Wool is a natural material often used in the top layers of mattresses.
It's a popular choice due to its comfort, ability to regulate temperature, and natural flame-retardant properties.
Pros
Cons
Cotton is a breathable and soft material. It's commonly used in mattress covers and batting.
Conventional cotton is notoriously bad for the environment, due to pesticide usage and high water consumption.
But organic cotton is much more sustainable than traditional cotton. It's a popular material in eco-friendly organic mattresses.
Pros
Cons
Bamboo fabric is gaining popularity for its sustainability and softness.
It's often used in the covers of bamboo mattresses.
Pros
Cons
Flame retardants are chemicals added to materials to meet fire safety standards.
Pros
Cons
In organic and non-toxic mattresses, an organic wool layer is used instead of chemical flame retardants.
Greener foams, such as plant-based memory foam, are more eco-friendly than traditional foams.
However, caution is needed when shopping for greener foams as the industry is rife with greenwashing. For example, 1% plant-based materials do not instantly make memory foam non-toxic and sustainable.
Pros
Cons
Polyester is a synthetic material commonly used in mattress fabrics for its long-lasting nature and affordability.
It's created through a process that starts with refining petroleum. This is combined with chemicals and water to form a polymer resin. This resin then undergoes further processing to be transformed into polyester fibers.
Find out more in our guide: Is polyester toxic?
Pros
Cons
Gel-infused foam is a blend of traditional memory foam and cooling gel particles.
This hybrid material aims to address the common heat retention issue.
Pros
Cons
Silk and cashmere are renowned for their luxury and comfort and are often used in some of the world's most expensive mattresses.
Silk is a natural protein fiber known for its softness and sheen.
Cashmere, derived from cashmere goats, is prized for its softness and warmth.
Pros
Cons
Horsehair, specifically horses' mane and tail hair, has been used in mattress-making for centuries.
Pros
Cons
Coconut coir is a natural fiber extracted from coconut husk.
It's a sturdy and natural material that provides a firm and supportive mattress layer.
Pros
Cons
TENCEL is a brand name for Lyocell. It's becoming increasingly popular in the mattress industry for its eco-friendly and comfortable properties.
TENCEL is made from wood cellulose, primarily from eucalyptus trees.
Pros
Cons
Recycled materials, such as steel coils or recycled plastics and fabrics, can be repurposed to create new mattresses.
Pros
Cons
Recycled steel is used to make the coils of some innerspring and hybrid mattresses, two of the four main types of mattresses sold today.
The four different types of mattresses are innerspring, memory foam, latex, and hybrid, each defined by the materials in its support core and comfort layers.
The following table compares the four types by their construction, feel, the sleeper each suits best, and their main drawback.
| Innerspring | Memory foam | Latex | Hybrid | |
|---|---|---|---|---|
| Support core | Steel coil unit | High-density polyfoam | Firm Dunlop latex | Pocketed steel coils |
| Comfort layers | Thin fiber or foam padding, sometimes a pillow top | Memory foam over a polyfoam transition layer | Softer Dunlop or Talalay latex | Foam or latex over the coils |
| Feel | Springy. The coils push back, and you lie on top of the padding | Slow sink, the foam molds around your body | Bouncy. The latex gives a little and then lifts you back up | Coil bounce under a cushioned top |
| Best for | Shoppers on the lowest budget | Side sleepers who want the mattress to cradle the shoulder and hip | People who want an organic mattress with no polyurethane foam | Couples, when the coils are individually wrapped |
| Main drawback | The comfort layer is the thinnest of the four types, so you feel the coils once the padding compresses | Most memory foam is petroleum-based polyurethane, which is not eco-friendly and contains chemicals. | Blended and synthetic latex are also sold as "latex", so only the label shows how much natural latex is inside | "Hybrid" can mean coils under budget polyfoam as well as coils under organic latex, so check which material sits on the coils before buying |
Certified latex, hybrid, and non-toxic memory foam mattresses are ranked in our guide to the best eco-friendly mattresses.
Whichever of the four types you choose, independent certifications are the only way to confirm that the materials inside have been tested for harmful chemicals.
Mattress materials certifications keep you safe by having an independent certifier test a mattress material against a published limit for a harmful chemical.
Mattress certifications set limits on the VOCs that memory foam and polyfoam give off, on chemical flame retardants, on pesticide residues in conventional cotton, and on the processing chemicals in bamboo fabric.
Our guide to organic mattress certifications explains what the certifications mean and which chemicals they test for.
Hybrid mattresses typically combine innerspring coils with foam layers.
Flippable mattresses often have a symmetrical construction with comfort layers on both sides and a supportive core in the middle. These layers can include foam, latex, or mini coils designed to offer balanced support and comfort from either side.
The environmental impact of disposing of an old mattress depends on how the mattress is disposed of.
In a landfill, the polyurethane foam in a mattress leaches chemical additives into the ground as the foam breaks down. Incinerating a mattress releases carbon dioxide. A mattress dumped illegally harms the area it is left in and costs public money to clear.
The most eco-friendly disposal method is recycling your old mattress because in a recycling center, the mattress is taken apart and its steel, foam, and fabric are reused.
