Fire Rated Insulation
Insulation classified A1 or A2, s1-d0 according to the Euroclass system, can reduce the risk of fuelling a fire
Non-combustible insulation can play a key role in helping to mitigate the risk of fire spreading within a building. Stringent European Reaction to Fire classifications such as Euroclass A1 and Euroclass A2-s1,d0, explain a material’s reaction to fire properties. By using non-combustible insulation solutions (Euroclass A1), buildings can be designed to reduce fire risk for safer living and working environments.
Euroclass A1 and Euroclass A2-s1,d0
The European Reaction to Fire Classification of construction products and building elements (EN 13501-1:2018), or Euroclass system is widely used across Europe and the UK to evaluate the reaction to fire of construction products and building materials. Materials tested using this system can be classified from A1 to E based on how they behave when exposed to fire . There is also F Class – materials classified as F are either untested or do not meet the criteria.
Euroclass A1 is used for materials that are non-combustible. This means they will not contribute to development or fire spread in any significant way – and they will not ignite, produce flames, smoke, or flaming droplets when exposed to fire. Many Isover glass mineral wool products, such as Isover Acoustic Partition Roll, Isover Spacesaver Loft Insulation, Isover Cavity Wall Slab, and Isover Timber Frame Insulation achieve Euroclass A1 reaction‑to‑fire classification
Euroclass A2-s1, d0 materials are classified as having very limited contribution if exposed to fire. Euroclass A2-s1, d0 products will also be assessed for additional criteria, such as the likelihood for smoke production (s1-3) or any character change (d0-d2), when exposed to fire. There are three smoke intensity levels s1 - s3 with s3 being the worst, and three classes for character changes such as the tendency to produce burning droplets, particles,. d0 - d2 with d2 being the worst. The additional criteria for a product to produce smoke and flaming droplets or particles is valid for products rated Euroclass A2 - D. Isover offers a range of Euroclass A2-rated insulation products suitable for various applications such as Isover Climcover Roll Alu2.
The benefits of non-combustible insulation
Being non-combustible, mineral wool can help reduce the risk of contributing to a fire or increasing the fire load. Let’s look at more benefits and related products.
Many glass and stone mineral wool products are rated A1 in the Euroclass Reaction to Fire Classification System. This means that they do not contribute to a fire and they do not emit any smoke or flaming droplets .
Isover products are tested in accordance with BS EN 13501-1:2018 and CE & UKCA marked for their specific applications and intended use
Understanding ‘reaction to fire’ and ‘fire resistance’
There are two key provisions often discussed in relation to insulation and fire safety:
- Reaction to fire
- Fire resistance.
It’s important to understand the difference between these two descriptions when specifying products for fire safety applications.
Reaction to fire evaluates how a material contributes to fire development and spread. A product's performance is critical in the early stages of a fire.
Fire resistance measures the ability of a complete system to resist fire penetration and maintain performance over a defined period. Fire resistance becomes essential once a fire is established, by helping to contain its spread.
Learn more about fire resistant insulation
Get to know fire-rated insulation better with these articles written by our development teams and insulation specialists.
Learn how fire-safe insulation protects buildings while supporting efficiency and comfort
Isover fire-rated insulation products
Mineral wool insulation products can contribute to the fire resistance performance of a system , for example when used in various British Gypsum GypWall systems . The following selection from Isover includes products that have been tested and classified under relevant acoustic and thermal performance.
Isover Modular Roll
Multi-purpose Thermal Insulation
Isover Cladding Roll 37
Thermal Insulation for built-up metal roofs and walls
Isover Cavity Wall Slab (CWS) 32
Thermal Insulation for External Masonry Cavity Walls
Isover ULTIMATE™ industrial fire insulation products
Designed to be used in demanding industrial applications, ULTIMATE™ slabs and wired mats are next-generation mineral wool products tested to the relevant British and European fire resistance standards and offer up to two hours of fire protection.
Isover U Protect Slab 4.0 Alu1
Isover Ultimate™ mineral wool slabs for fire protection of rectangular ductwork.
Isover U Protect Wired Mat 4.0 Alu1
Isover Ultimate™ mineral wool wired mats for fire protection of circular ductwork.
Isover U Protect Accessories
Accessories to be installed with the U Protect System for passive fire protection of ductwork.
Frequently Asked Questions
I have severe allergies, and my contractor is installing Isover. What’s in the product?
We are unable to provide specific case advice – however, please refer to our Safe Use Instruction Sheet (SUIS), a link to which you’ll find below. Our product contains less than 1% mineral oil, which is added to reduce dusting of the glass mineral wool.
For more details, please read are SUIS Sheet here
Does your insulation contain palm oil?
No. Isover insulation does not contain palm oil.
Is Isover packaging recyclable?
Yes. In 2025, we also reduced the ink coverage in our white packaging to less than 15%. This reduction means our packaging can now be used to produce a wider variety of items made of recycled content than previously. This is because using a higher proportion of white plastic makes it more versatile. Our packaging also contains 30% Post Consumer Recycled content, which means less raw virgin materials go into our packaging and further strengthens our commitment to sustainability.
Do you recycle leftover insulation?
Isover doesn’t currently offer a customer recycling service. If you do need to dispose of leftover insulation, residues or by-products, this should comply with the requirements of environmental and waste disposal legislation and any local authority rules.