Pyrosorb-S Class 0 Foam Sheets

Fireseal Class 0 Foam Sheet — B-s1,d0 Fire Rated Acoustic Foam, >90kg/m³, UK Made

Regular price £33.99 Sale

Fireseal is a Class 0 fire retardant acoustic foam: an impregnated polyurethane foam with a density above 90 kg/m³, rated EN 13501-1 B-s1,d0 and UL94 94-V-0. Manufactured in the UK to ISO 9001.

It is used where a foam has to both absorb sound and resist the spread of flame: air conditioning and duct systems, generator rooms, engine bay compartments, oil rigs, MOD vehicles, prison mattresses, marine and automotive applications, and recording studios.

Is Class 0 the right rating for what you are doing?

This is the question worth getting right, because Class 0 and Crib 5 are routinely confused and they are not interchangeable.

Standard What it tests When you need it
Class 0 Surface spread of flame and fire propagation on a building surface, under UK Building Regulations. Assessed via BS 476 Parts 6 and 7. Wall and ceiling linings, ductwork, HVAC, plant and generator rooms, acoustic treatment within a building.
Crib 5 Ignition resistance of furniture, under BS 5852 Ignition Source 5 (a small wooden crib). Contract and commercial seating — sofas, chairs, mattresses, upholstered furniture.

In short: lining a room, sealing a duct or treating a plant room — Class 0 is what you want, and this is the product. Re-covering a sofa or chair — Class 0 is not the relevant standard, and you want a Crib 5 upholstery foam from our main range instead.

Fire performance

Test Result
EN 13501-1 Euroclass* B-s1,d0
BS 476 Part 6 — Fire Propagation Index <12 (>6mm)
BS 476 Part 7 — Surface Spread of Flame Class 1
Building Regulations Paragraph A13(b) Class 0
UL94 Classification 94-V-0
ASTM E84-09 — Surface Burning Flame Spread Index 10 · Smoke Developed Index 20
ASTM C411-04 — Hot Surface Performance @100ºC, 96hr Pass

*Euroclass certification covers 6mm–50mm adhered, and 50mm unadhered.

Acoustic performance

Thickness Sound absorption coefficient
12mm αw 0.30
25mm αw 0.45
75mm αw 0.75

Absorption rises with thickness — 75mm absorbs roughly two and a half times as much sound energy as 12mm.

Specifications

Type Impregnated polyurethane foam, open cell
Colour Dark grey
Density >90 kg/m³
Thickness range 6mm – 100mm (stocked: 10mm, 25mm, 50mm)
Sheet size 200 x 100cm (78.7" x 39.3")
Operating temperature -30ºC to 100ºC
Air erosion resistance (ASTM C1071-05, 6–50mm) Pass — does not erode or migrate in air movement up to 6000 ft/min
Fungus / mildew resistance (ASTM D-2020-92, G21-96) Does not support growth
Water vapour sorption (ASTM C1104-06) <9%
Thermal conductivity (ASTM C518-04) 0.32 Btu-in/ft²-hrºF @ 6mm
Fibre content Non-fibrous
Manufactured United Kingdom, to ISO 9001

Typical applications

  • Air conditioning and duct systems
  • Generator rooms and plant rooms
  • Engine bay compartments · marine and automotive
  • Oil rigs and MOD vehicles
  • Recording studios and acoustic treatment where building fire regs apply

Questions about this foam

Is Class 0 foam the same as Crib 5 foam?

No. Class 0 is a UK Building Regulations rating for the surface spread of flame on building surfaces, assessed under BS 476 Parts 6 and 7. Crib 5 is BS 5852 Ignition Source 5, a furniture ignition test. Class 0 applies to a wall, ceiling or duct. Crib 5 applies to a sofa or mattress. They are not interchangeable.

What does B-s1,d0 mean?

It is the EN 13501-1 Euroclass rating. B is the reaction-to-fire class (very limited contribution to fire). s1 is the smoke rating — the lowest, meaning very little smoke. d0 is the flaming droplets rating — the lowest, meaning no flaming droplets. In an escape scenario, smoke and droplets matter as much as flame spread.

Will this soundproof a room?

No — it is a sound absorber. It reduces reflections, echo and reverberation within a room. It will not stop sound passing through a wall, which is a different problem requiring mass, not foam. Its advantage over standard acoustic foam is the Class 0 rating, which matters wherever building fire regulations apply.

Why does it being non-fibrous matter?

In air-handling applications, fibrous insulation can shed fibres into the airstream. Fireseal is non-fibrous and tested to ASTM C1071-05 for air erosion resistance up to 6000 ft/min — it does not erode or migrate in moving air, which is why it can be used inside ductwork and air conditioning equipment.

For the full explanation of density, firmness and fire ratings, see our foam FAQs. To compare every grade side by side, see our foam grade comparison.

Cut to order in our own UK factory. Next working day delivery is available to most of the UK — see our delivery page for timings to your area.

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