BS EN 13501-1 is a European Standard that provides a harmonised procedure for classifying the reaction to fire of construction products. This classification is crucial for ensuring the safety and consistency of building materials across the EU. It covers construction products, floorings, and linear pipe thermal insulation products in their end-use conditions.
Classification Levels
BS EN 13501-1 categorises materials into seven classes based on their reaction to fire:
- A1: Non-combustible materials, do not contribute to the development of a fire.
- A2: Materials with limited combustibility, do not significantly contribute to the development of a fire.
- B: Combustible, limited contribution to fire.
- C: Combustible, minor contribution to fire.
- D: Combustible, contributes to fire.
- E: Combustible, resists a small flame for a few seconds.
- F: Materials not classified or not meeting the minimum requirements of Class E.
Required Tests for Each Classification
BS EN 13501-1 specifies which tests are necessary for each classification, ensuring a consistent approach across different products.
Conditioning (BS EN 13238:2010)
Products must be conditioned before testing to ensure consistency:
- Constant Mass: Weigh samples every 24 hours until the mass difference is less than 0.1% or 0.1g.
- Fixed Period: Varies from 2 to 8 weeks depending on the product type.
Single Flame Source (BS EN ISO 11925-2:2020)
Required for classes B, C, D, and E, this test assesses the ignitability of products by a small flame.
Single Burning Item Test (BS EN 13823:2020)
Required for classes A2, B, C, and D, this test evaluates the fire performance of products when exposed to a thermal attack by a single burning item.
Non-combustibility (BS EN ISO 1182:2020)
Required for classes A1 and A2, this test determines if a product significantly contributes to a fire when exposed to 750°C.
Heat of Combustion (BS EN ISO 1716:2018)
Also required for classes A1 and A2, this test measures the maximum total heat release of a product when completely burned.
Euroclass Table of Reaction to Fire Classification
| Class | Reaction to Fire | Additional Tests Required |
| A1 | Non-combustible, no fire contribution | Non-combustibility, Heat of Combustion |
| A2 | Limited combustibility, no significant fire contribution | Non-combustibility, Heat of Combustion, SBI Test |
| B | Limited contribution to fire | Single Flame Source, SBI Test |
| C | Minor contribution to fire | Single Flame Source, SBI Test |
| D | Contributes to fire | Single Flame Source, SBI Test |
| E | Resists a small flame for a few seconds | Single Flame Source |
| F | Not classified or does not meet E requirements | None |
BS EN 13501-1 provides a unified framework for assessing the fire reaction of construction products, ensuring safety and standardisation across the United Kingdom and Europe. By specifying detailed test methods and classification criteria, it helps manufacturers and regulators maintain high safety standards in building materials.
