Fire safety is one of the most important considerations in architecture and construction. In the event of a fire, building occupants need enough time to evacuate safely, and that depends in part on the materials used throughout the project and how they respond when exposed to flames, heat and smoke.

The European Union uses Standard EN 13501-1, which classifies construction products and building elements according to their reaction to fire. This system provides a consistent way to compare material performance using standardized testing methods, and it is used as a reference in many countries around the world.

Euroclass ratings help architects, specifiers and construction professionals understand how materials behave in a fire by evaluating combustibility, smoke production and the formation of flaming droplets.

Fire-resistant materials used in construction

When selecting materials for a building, fire performance should be considered from the earliest stages of the project. The right material choices can help reduce risks and support safer evacuation conditions in the event of a fire.

These are some of the materials commonly recognized for their fire-resistant properties:

Glass

Fire-rated glass is usually made with several layers of glass and intumescent gel. This composition allows it to act as a barrier against flames, radiant heat and gases. Depending on its EI rating, which refers to integrity and insulation, this type of glass can maintain its performance for more than 60 minutes. It is often used in corridors, shared areas and spaces where safety, visibility and design must work together.

Concrete

Concrete is widely used in construction because of its strong fire performance. It is non-flammable, does not release toxic gases and its thermal mass helps slow down heat transfer. When properly designed and reinforced, concrete elements such as walls and floors can maintain structural strength for long periods of fire exposure.

Ceramic brick

Ceramic brick can provide fire resistance for more than 120 minutes, depending on the system used. Its inorganic composition and porous structure help slow the spread of fire. When installed with mortar coatings and additional fire-resistant insulation layers, its performance can be significantly improved. This makes it a useful option for interior partitions and compartmentalization systems.

Krion® Lux

Krion® Lux is a Solid Surface material composed mainly of Alumina Trihydrate, or ATH, and high-strength resins. This formulation gives it strong fire performance, making it suitable for architectural applications where safety is an important requirement.

Among its properties, Krion® Lux stands out for its thermal stability, inert composition and low thermal conductivity. These characteristics allow the material to withstand high temperatures without easily deforming or degrading. Its composition does not feed flames or contribute significantly to fire spread. In addition, its low smoke production can support safer evacuation conditions during a fire.

Another important advantage is that Krion® Lux does not generate flaming droplets, helping reduce the risk of igniting nearby materials. Its low thermal conductivity also slows heat transmission, helping protect the surrounding space and reinforcing its suitability for public, health care and commercial environments.

Gypsum

Gypsum, especially in the form of fire-rated boards, incorporates glass fibers and specific additives to improve thermal performance. It can help regulate heat because it releases water vapor during the early stages of a fire, slowing down the rise in temperature.

Stucco

Stucco based on hydraulic lime or gypsum can provide an additional layer of thermal protection when applied as a continuous finish. Its fire performance depends on its thickness and composition, but it can add between 30 and 90 minutes of fire resistance when used with fire-retardant substrates.

 

 

 

Fire classification systems

The UNE-EN 13501 standard classifies materials according to their reaction to fire. Krion® Lux has obtained the B-s1-d0 classification. To understand what this means, it is helpful to review the different parts of the Euroclass system.

Contribution to fire: A1, A2, B, C, D, E and F

Contribution to fire indicates whether a material helps sustain or spread a fire.

• Class A refers to non-combustible materials that do not contribute to fire, such as stone.
• Class B applies to combustible materials with a very limited contribution to fire.
• Class C indicates a combustible material with limited contribution to fire.
• Class D refers to combustible materials with a moderate contribution to fire.
• Class E applies to combustible materials with a high contribution to fire.
• Class F is used for materials that have not been tested or classified.

Smoke production: s1, s2 and s3

This classification measures the amount and opacity of smoke produced by the material. There are three ratings, from lowest to highest smoke production:

• s1 indicates low smoke production.
• s2 indicates medium smoke production.
• s3 indicates high smoke production.

Flaming droplets: d0, d1 and d2

This part of the classification evaluates whether a material produces flaming droplets or particles that could contribute to fire spread.

• d0 means that no flaming droplets or particles are produced.
• d1 means that droplets or particles may be produced, but they are not inflamed.
• d2 means that inflamed droplets or particles may be produced.

What does the B-s1-d0 Euroclass rating mean?

Krion® Lux has obtained the B-s1-d0 Euroclass rating under the European reaction-to-fire classification system. This rating provides useful information about how the material behaves when exposed to fire.

For Krion® Lux, the classification can be understood as follows:

1. CONTRIBUTION TO FIRE (B): This rating indicates that Krion® Lux is a combustible material with a very limited contribution to fire.
2. SMOKE PRODUCTION (s1): The s1 rating is the highest performance level in this category, meaning that Krion® Lux produces low levels of smoke.
3. FLAMING DROPLETS (d0): The d0 rating means that the material does not produce flaming droplets or particles, helping reduce the risk of fire spread to nearby materials.

 

Thanks to the EN 13501-1 fire classification standard for construction products and building elements, the performance of Krion® Lux can be assessed with clear and standardized criteria.

In addition to offering design flexibility and architectural versatility, Krion® Lux provides an added level of reliability for projects where fire performance, safety and material quality are essential.