BS 476 Is Being Retired: What the Move to BS EN 13501 Means for Fire Classification
The UK is replacing its long-standing BS 476 fire test standard with the European BS EN 13501 system in stages, and old test results do not automatically carry over.
INFIRISK Team·2 min read·
The UK is part-way through replacing its long-standing fire test standard, BS 476, with the European BS EN 13501 classification system. For anyone specifying, assessing or maintaining fire safety in buildings, this is a change worth tracking, because a test result that was valid yesterday may not be accepted tomorrow.
What is changing
The government confirmed the withdrawal of the old National Class fire testing standards from Approved Document B in September 2024. In their place comes the BS EN 13501 series, which classifies both how a product reacts to fire and how well it resists the spread of fire. The change applies to construction products used in England and Wales.
The timeline
The switch is happening in stages rather than all at once:
Reaction to fire came first. On 2 March 2025, BS 476 Part 7 was withdrawn from Approved Document B, making BS EN 13501-1 the mandatory standard for the reaction to fire classification of construction products.
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Fire resistance follows next. A second amendment is scheduled for 30 September 2026, moving fire resistance testing across to the European system.
Full phase-out lands in 2029. The final amendment takes effect on 2 September 2029, at which point BS 476 is fully retired from the guidance.
Why it matters for existing results
The most important practical point is that old BS 476 results do not automatically carry over. Products generally need to be retested to the relevant BS EN 13501 method, because the European standard tests differently and, in many respects, more rigorously. Assessors and specifiers should not assume a historic National Class rating still satisfies the current guidance.
The wider context
The move aligns with the direction set by the Hackitt review after Grenfell, which pressed for a clearer and more robust framework for building safety. BS EN 13501-1 is widely regarded as a more comprehensive and revealing test regime than the standard it replaces, giving a fuller picture of how a material behaves in a fire.
If you rely on product fire ratings in assessments or specifications, check whether the evidence you hold is expressed in National Class terms or the BS EN 13501 classes. Where a product still carries only a BS 476 rating, ask the manufacturer for the current European classification, and plan for the 30 September 2026 fire resistance change well ahead of the deadline.
