Is Spray Foam Insulation Toxic in the UK? (2025 Health & Safety Guide)

Spray foam insulation is widely used in UK homes—but is it safe? With reports of respiratory irritation, lingering odours, and even home sale delays, many homeowners are asking if spray foam is toxic. In this 2025 guide, we explore what’s in spray foam, the risks, UK safety standards, and how to reduce exposure.

1. What’s in Spray Foam Insulation?

Spray foam insulation is made from two main components:

• Isocyanates (typically MDI)
  
  
• Polyols mixed with flame retardants, blowing agents, and surfactants
  
  

When combined on-site, they form a chemical reaction that expands and hardens into foam. During application and curing, the foam emits volatile organic compounds (VOCs)—which can be harmful if inhaled.

Related: Is Spray Foam Safe After Installation?

2. Is Spray Foam Insulation Toxic to Humans?

In its uncured state, yes—spray foam can be toxic. Key health risks include:

• Respiratory problems from isocyanate exposure
  
  
• Skin and eye irritation
  
  
• Headaches and nausea due to VOCs
  
  

These effects are most likely during and immediately after installation. Once fully cured (after 24–72 hours), the foam becomes inert—but residual odours and VOC traces can linger.

3. UK Regulations on Spray Foam Safety

As of 2025, spray foam is regulated under:

• REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals)
  
  
• UK COSHH (Control of Substances Hazardous to Health)
  
  
• Building Regulations Part L (Energy Efficiency)
  
  

Installers must follow strict guidelines on ventilation, PPE (personal protective equipment), and post-installation clearance times. However, the industry is largely self-regulated, which increases the risk of poor installations.

Related: Is Spray Foam Legal in the UK?

4. Signs You May Have a Problem with Toxic Spray Foam

Some homes continue to experience issues even after installation. Signs to watch for:

• Persistent chemical odour
  
  
• Respiratory irritation in occupants
  
  
• Pets avoiding certain areas of the home
  
  
• Discomfort when heating is turned on
  
  

In these cases, it’s important to get a VOC test or indoor air quality assessment.

5. Who’s Most at Risk from Spray Foam Toxins?

Certain individuals are more vulnerable to spray foam off-gassing:

• Children and babies
  
  
• Elderly individuals
  
  
• People with asthma or chemical sensitivities
  
  
• Pets (especially dogs and cats)
  
  

6. How to Protect Yourself if You Have Spray Foam at Home

• Ensure your spray foam was installed by a certified expert
  
  
• Use an air quality monitor
  
  
• Increase loft ventilation (roof vents, air bricks)
  
  
• Avoid disturbing the foam layer, especially if you see cracks or degradation
  
  

Need help removing unsafe foam? Explore our Spray Foam Removal Services

7. Can You Remove Spray Foam If It’s Causing Symptoms?

Yes—removal is often recommended in cases of toxicity or poor installation. However, it must be done professionally to avoid damaging the roof or releasing more fumes.

Learn more: Spray Foam Removal Without Damage

Frequently Asked Questions

Is spray foam toxic after it cures?
Once cured, it’s considered inert—but some sensitive people still react to trace VOCs.

Can spray foam affect pets?
Yes—pets are highly sensitive to chemical odours and off-gassing.

Should I remove spray foam if I smell chemicals?
If the smell persists beyond a few days and causes symptoms, professional removal is advisable.

How do I test air quality at home?
Use a VOC or indoor air quality monitor. Some smart home devices include this.

Can I safely install spray foam myself?
DIY installations are not recommended—it’s a hazardous chemical mix requiring PPE and professional knowledge.

Concerned about toxicity or poor spray foam installation? Get a specialist assessment or explore removal options through Snug & Secure.