Euroclass Fire Rating A2 – Limited Combustibility Classification (EN 13501-1)

The Euroclass system, established under EN 13501-1, is the European standard for classifying the fire performance of construction products. It evaluates how materials react to fire in terms of combustibility, smoke production, and flaming droplets/particles.

Core Classification: A2

• A2 indicates limited combustibility. Materials in this class may contain small amounts of organic content but do not significantly contribute to fire growth.
• These materials are not fully non-combustible (like A1), but they are still considered safe for use in critical applications such as external wall cladding and fire-rated partitions.

Extended Classification Components

• s1 = little or no smoke
• s2 = moderate smoke
• s3 = substantial smoke d0, d1, d2 Flaming droplets/particles:
• d0 = none
• d1 = some
• d2 = significant

Example: A2-s1,d0 is a high-performance rating indicating limited combustibility, minimal smoke, and no flaming droplets.

Testing Protocols

• EN ISO 1182: Non-combustibility test
• EN ISO 1716: Gross heat of combustion
• EN 13823 (SBI test): Single Burning Item test for smoke and droplet behavior
• EN ISO 11925-2: Ignitability test using a small flame

These tests simulate real fire scenarios, such as a room fire, to assess how materials behave under thermal stress.

Typical A2-Rated Materials

• Stone wool and mineral wool insulation
• Fibre cement boards
• Fire-resistant plasterboards
• Aluminium composite panels with mineral cores
• Certain glass-reinforced gypsum boards

Regulatory Use & Building Safety

• Required for external wall systems on buildings over 18m in height in the UK
• Commonly specified in facades, service risers, ductwork, and fire-rated partitions
• Helps meet compliance with Approved Document B, BS 8414, and Construction Products Regulation (CPR)