Is Polyurethane Safe – or Could It Cause Cancer?

Polyurethane is a synthetic material used in lots of everyday items – from mattresses, sofas and pillows to packaging foams, wood finishes, car seats and even some clothing. It’s everywhere, even if you’ve never really paid attention to it.

I started looking into polyurethane when I was shopping for a new mattress and realised most options were made from PU foam. That made me wonder whether I should avoid it and stick to more natural materials, just in case there were any long-term health risks I didn’t know about.

So is polyurethane something you really need to worry about – especially when people mention cancer? Here’s what I found when I looked into the science.

Quick answer

Polyurethane itself, once it’s set and finished, isn’t considered a cancer risk in normal home use. Most concerns focus on the chemicals used to make it, some flame retardants and toxic fumes if it burns, plus a separate issue with polyurethane-coated breast implants.

How is polyurethane made? (And why this matters for cancer risk)

It helps to know how polyurethane is made, because most of the worry around cancer is linked to the ingredients and the manufacturing process, not the finished mattress or sofa you have at home.

The basic chemistry in plain English

Polyurethane is created by reacting two main ingredients:

Isocyanates – very reactive chemicals that help “build” the plastic structure
Polyols – long-chain molecules that help decide how soft, firm or rigid the final material will be

On top of that, manufacturers often add:

Catalysts – to make the reaction happen faster
Blowing agents – to create bubbles and turn the mix into foam
Additives – for colour, flexibility or flame resistance

All of this usually happens in factories or on building sites, not in your living room.

This is important: the highest chemical exposures tend to happen where polyurethane is made or sprayed, which is mainly a worker safety issue, not a “lying on your mattress” issue.

Soft foam, rigid foam and coatings

The same basic chemistry can create different types of polyurethane, depending on the recipe and how it’s processed:

Flexible foams – for mattresses, sofas, pillows and cushions
Rigid foams – for insulation boards and fridge/freezer walls
Coatings and varnishes – thin layers in floor finishes, wood varnish and some paints

Change the formula slightly and you get something soft, hard or thin – but it’s all still polyurethane.

What happens when polyurethane “sets”?

When polyurethane is first made, the ingredients are still reacting and the material is in the process of setting (chemists call this “curing”).

Once that reaction has essentially finished, the foam or coating is set and stable – it behaves like a solid plastic, not a soup of raw chemicals.

At that stage, direct contact with the finished foam isn’t the main cancer concern. Instead, most of the discussion focuses on:

any tiny residues left over from the manufacturing process
additives, such as certain flame retardants
emissions (like VOCs and fumes), especially if the material burns

Those are the areas researchers and regulators pay most attention to, and we’ll look at them in more detail next.

Polyurethane and worker cancer risk

When you see cancer mentioned in relation to polyurethane, it’s usually not about sofas or mattresses. It’s about people working with the raw chemicals that are used to make polyurethane in factories or on building sites.

Isocyanates like TDI and MDI

Two key building blocks for polyurethane are isocyanates (a family of very reactive chemicals used to make many plastics and foams), especially:

TDI (toluene diisocyanates) – mainly used in flexible foam
MDI (methylene diphenyl diisocyanate) – widely used in rigid foams and other PU products

The International Agency for Research on Cancer (IARC) classifies TDI as “possibly carcinogenic to humans” (Group 2B), based on animal studies and limited human data.

MDI is currently “not classifiable” as to its carcinogenicity in humans (Group 3), which means the existing evidence is too weak or inconsistent to say either way.

Some studies of polyurethane foam workers have found higher-than-expected lung cancer deaths in groups exposed to TDI over many years. But these workers were also exposed to other substances (like solvents and dust), and the results haven’t been completely consistent, so it’s hard to pin the blame on TDI alone.

What is clear is that breathing in isocyanates over time is harmful for the lungs. They are well-known causes of occupational asthma and other breathing problems, which is why strict safety measures are required in workplaces that use them.

Other chemicals such as MBOCA

Another chemical sometimes used in the polyurethane world is MBOCA (4,4′-methylenebis(2-chloroaniline)), a curing agent for certain heavy-duty cast polyurethane parts, such as industrial rollers.

Here the cancer link is stronger:

IARC classifies MBOCA as a Group 1 carcinogen (carcinogenic to humans), largely due to strong evidence from animal studies and how the chemical behaves in the body.
Occupational studies have linked MBOCA exposure to bladder cancer in workers who handle it directly, especially in plants with poor controls or limited protective equipment.

This is very specific: it’s about workers dealing with the pure chemical, not people using everyday polyurethane products.

What this means for you as a consumer

The key difference is how much and how often people are exposed:

Workers who handle isocyanates or MBOCA can be exposed to much higher levels, often day after day, over many years.
Everyday contact with finished polyurethane foam (like sitting on a sofa or sleeping on a mattress) is in a completely different exposure range.

So while there is a real cancer concern in some occupational settings – and that’s why regulations, ventilation and protective equipment are so important – this doesn’t mean that normal use of finished polyurethane products at home carries the same kind of cancer risk.

Polyurethane in your home: what are the real worries?

For most people, the main questions aren’t about factories – they’re about everyday things like mattresses, sofas and foam cushions. When it comes to cancer, the focus is less on polyurethane itself and more on what’s added to it or what happens if it burns.

Flame retardants in foam

For many years, a lot of polyurethane foam used in furniture and mattresses was treated with chemical flame retardants so it could pass strict fire tests.

Some of the older flame retardants used in foam, such as TCEP and TDCPP, have raised health concerns. Animal and lab studies suggest they could increase cancer risk, and they now appear on “hazard lists” or are restricted in places like the EU and California.

When researchers tested foam from sofas and children’s products, they found these flame retardants in a significant number of samples, showing how widely they were used in the past.

Because of these concerns, rules have started to change and many manufacturers have moved away from the worst offenders. Newer furniture often relies more on barrier fabrics, different foam formulations or other design changes, so it can meet fire regulations without heavy use of these older chemicals.

What this means in practice:

Older sofas and mattresses are more likely to contain these flame retardants, especially if they were made before regulations tightened.
Some very cheap or imported products may still use them.
Newer, well-regulated products are less likely to rely on these older chemicals and may be labelled as “no added flame retardants” or “low emission”.

So if there is any long-term cancer concern in the home, it’s mainly about certain flame retardant additives, not the polyurethane foam itself.

Off-gassing and “new mattress” smells

That “new mattress” or “new sofa” smell comes from volatile organic compounds (VOCs) – small chemicals that evaporate from foam, glues and fabrics and build up in indoor air.

Some VOCs (for example, benzene or formaldehyde) are classified as carcinogens at high or long-term exposures, and studies show that polyurethane foam mattresses can emit a mix of VOCs, especially when brand new.

For most people using modern, certified products:

VOC levels are relatively low,
they tend to drop off over days to weeks, and
short-term issues, if they happen, are usually things like headaches, irritation or breathing discomfort in people who are sensitive.

So VOCs are a good reason to air out new products and, if you’re sensitive, to choose low-emission options – but at normal household levels they are generally seen as more of an air-quality and comfort issue than a clearly proven long-term cancer trigger.

Polyurethane in fires

Polyurethane foam is highly flammable, and if it catches fire it can burn quickly and produce very toxic smoke. Fire tests and real incidents show that burning polyurethane releases large amounts of carbon monoxide (CO) and hydrogen cyanide (HCN), along with other irritating gases.

In a house fire, these gases can cause rapid poisoning and death within minutes. This is the main health danger from polyurethane in fires – an acute, life-threatening risk, rather than a slow, long-term cancer issue.

Polyurethane mattresses: should you be worried?

Based on current risk assessments, the cancer risk from tiny traces of chemicals like TDI in polyurethane foam mattresses is considered extremely low and well below health safety limits.

In everyday life, the bigger issue is short-term smell and VOCs when a mattress is new, which usually drop off within days or weeks. If you want to be cautious, choose a low-emission certified mattress, air it out well before use, and replace very old, crumbling foam rather than hanging onto it for decades.

Polyurethane breast implants and cancer

Polyurethane isn’t only used in mattresses and sofas – it’s also been used as a foam coating on some breast implants. Here the cancer questions are a bit different.

Early worries about breakdown chemicals

Years ago, doctors were worried that the polyurethane foam on some implants might slowly break down in the body and release a chemical called 2,4-TDA. In animal studies, high doses of 2,4-TDA were linked to cancer, and small amounts were found in the urine of women with these implants.

Because of this, the FDA and other experts looked at the numbers very closely. Later reviews concluded that the extra cancer risk from 2,4-TDA released by polyurethane-coated implants is extremely small – essentially close to zero for patients, and they did not recommend having these implants removed just for this reason.

BIA-ALCL: a rare lymphoma linked to textured implants

The bigger issue today is something different called breast implant–associated anaplastic large cell lymphoma (BIA-ALCL). This is a rare cancer of the immune system, not typical breast cancer, and it usually develops in the fluid or scar tissue around the implant.

BIA-ALCL has been found much more often in women with textured or polyurethane-coated implants than in those with only smooth implants. Health agencies in Australia, Europe and the US all highlight that the risk is tied to having an implant with a textured or rough surface.

Current estimates suggest that:

Polyurethane-coated and other highly textured implants have a risk in the low “one-in-thousands” range – for example around 1 in 1,800 for polyurethane-coated and 1 in 2,400 for some macro-textured implants in Australian data.
Larger reviews of textured implants in general put the risk somewhere between about 1 in 2,800 and 1 in 30,000.
Some countries report no confirmed cases in people who have only ever had smooth implants.

Because of this, several regulators have stopped approving or have withdrawn some textured and polyurethane-coated implants, although many women around the world still have them in place and most will never develop BIA-ALCL.

If you have breast implants and feel worried, the safest step is to speak to your surgeon or breast specialist, especially if you notice:

new swelling around the breast or implant
a lump in the breast or armpit
persistent pain, fluid build-up or a change in the shape of the breast

They can tell you exactly which implant you have, explain your personal level of risk and decide whether any tests or follow-up are needed. Routine removal is generally not recommended if you have no symptoms and your check-ups are normal.

Practical ways to reduce your exposure (without binning all your furniture)

You don’t need to panic or throw everything out. A few simple choices can keep your overall exposure low, especially in rooms where you spend a lot of time.

Smart choices when buying new mattresses and furniture

When you’re shopping for something new, it’s worth checking:

Labels that mention “no added flame retardants” or similar wording
Low-VOC or certified foams (for example CertiPUR, GREENGUARD, EU Ecolabel or other low-emission labels)
More natural materials if your budget allows – such as latex, wool, cotton and solid wood

This is especially useful for mattresses, sofas and nursery furniture.

What to do with polyurethane items you already have

You can also reduce exposure from things already in your home:

Air out new products (mattresses, sofas, rugs) in a well-ventilated room for a few days
Keep dust down with a HEPA vacuum and damp dusting, as some chemicals can cling to house dust
Replace very old, crumbling foam (especially decades-old mattresses or cushions that shed dust) rather than hanging onto them forever

Who might want to be extra careful?

The same basic tips apply to everyone, but a bit of extra caution can make sense if:

you work with polyurethane chemicals (foam plants, spray foam insulation, floor finishing)
you have asthma, allergies or chemical sensitivities and notice symptoms around new products
you’re buying for babies and young children, where many parents prefer low-VOC, no-added-FR mattresses and sofas in nurseries and bedrooms

These are simple, realistic steps that help lower your exposure without needing a completely “PU-free” home.

When might you choose to avoid polyurethane altogether?

You don’t have to avoid polyurethane completely, but some people prefer to be extra cautious. You might choose more natural options if:

you’re very sensitive to chemicals or smells and react strongly to new products
you’re trying to create a deliberately “low-tox” home and are happy to spend more or own fewer things

If that’s you, it usually makes sense to prioritise bedrooms and items close to your skin first – for example mattresses, pillows, bedding and the sofa you sit on every day – and look for natural materials like latex, wool, cotton and solid wood where you can.

Key takeaways

Polyurethane itself, in its finished form, isn’t classed as a human carcinogen in normal home use.
The bigger concerns are manufacturing chemicals, some older flame retardants and toxic smoke in fires, not day-to-day contact with foam.
Modern polyurethane mattresses and sofas are generally low-risk when they meet current safety and emissions standards.
Polyurethane-coated breast implants are a separate issue: BIA-ALCL is a rare but real lymphoma linked mainly to textured and PU-covered implants, not to household foam.
You can keep your overall exposure low by choosing low-VOC, well-certified products, airing out new items and replacing very old, crumbling foam when it’s time for an upgrade.