Crib 5 vs Crib 7: which flammability rating do you need?

For most contract upholstery in the UK — healthcare, hospitality and general public seating — Crib 5 is the flammability rating you need, and Crib 7 is the higher-hazard rating reserved for the most demanding settings. But the crib number is only half the picture. In the UK, contract seating is specified to BS 7176, which sorts furniture into fire-hazard categories by end use — Low, Medium, High and Very High — and then calls up the ignition sources defined in BS 5852 to test each one. Crib 5 is the source used for Medium Hazard; Crib 7 is the source used for High Hazard. So the practical question is rarely "Crib 5 or Crib 7?" but "which BS 7176 hazard category does this space fall into?" — the crib rating follows from the answer. Outside the UK, continental European projects are more commonly assessed against EN 1021-1 and EN 1021-2, covered further down.

What BS 5852 actually tests

BS 5852 is the British Standard that assesses the ignitability of upholstered seating when exposed to a series of escalating ignition sources. Crucially, it does not test the fabric in isolation — it tests the composite: the cover fabric assembled over a specified filling, in a configuration that represents real seating. This matters because the same fabric can pass or fail depending on the foam, interliner or wadding behind it.

The standard defines a ladder of ignition sources, increasing in energy and duration:

• Source 0 — a smouldering cigarette.
• Source 1 — a simulated burning match (a small butane flame).
• Sources 2 to 7 — a series of wooden cribs, small stacked timber assemblies that burn with progressively greater intensity and duration.

The principle is simple: the higher the crib number, the larger and hotter the ignition source, and the longer it challenges the seat before the test looks for continued flaming or smouldering. Crib 5 is a small timber crib of roughly 17 g; Crib 7 is a substantially larger one of roughly 126 g. A seat that resists Crib 7 has withstood a considerably more severe fire load than one certified only to Crib 5. Because performance is a property of the whole assembly, a "Crib 5 pass" always describes a fabric tested over a defined filling — never the textile on its own.

How BS 7176 turns those sources into a specification

BS 5852 is a test method. It defines the ignition sources and how they are applied, but it does not tell you which source your project needs. That job belongs to BS 7176, the British Standard specification for the resistance to ignition of upholstered furniture for non-domestic seating. BS 7176 sets out four fire-hazard categories based on how the furniture will be used, and for each category it prescribes the ignition sources the cover-and-filling composite must survive:

• Low hazard — a smouldering cigarette (as EN 1021-1) and a match-flame source (as EN 1021-2). No crib required.
• Medium hazard — the Low Hazard tests plus BS 5852 ignition source 5, i.e. Crib 5.
• High hazard — the Low Hazard tests plus BS 5852 ignition source 7, i.e. Crib 7.
• Very high hazard — the Low Hazard tests plus any BS 5852 ignition source at the specifier's discretion, which in practice can mean several source 7 cribs used together.

Two consequences are worth noting. First, the cigarette and match tests sit underneath every BS 7176 category — a Crib 7 specification still requires EN 1021-1 and EN 1021-2 performance as well. Second, BS 7176 is a specification for the finished item of furniture, not for a roll of fabric: it also requires the fillings to comply with the UK Furniture and Furnishings (Fire) (Safety) Regulations, and applies a mandatory water-soak and line-dry procedure to cover fabrics before testing.

For healthcare specifically, NHS Firecode guidance (HTM 05-03 Part C) recommends BS 7176 Medium or High Hazard according to location — which is where the familiar rule of thumb of "Crib 5 for wards and waiting areas, Crib 7 for higher-risk sleeping accommodation" comes from.

Crib 5: the Medium Hazard benchmark

Crib 5 is the rating most UK contract specifications call for by default, because it is the ignition source BS 7176 assigns to the Medium Hazard category — the category that covers the great majority of public-facing seating:

• Healthcare — hospital wards, waiting areas, day rooms and clinical seating.
• Hospitality — hotel bedrooms, restaurants, bars, public houses and casinos.
• Public buildings and places of entertainment — public halls, theatres, cinemas and assembly spaces.
• Hostels and comparable shared sleeping accommodation.

BS 7176 places offices, schools, colleges, universities, museums, exhibitions and day centres in the Low Hazard category, where the cigarette and match-flame tests alone are sufficient and no crib is strictly required. In practice, many contract specifications still call for Crib 5 across the board — partly because furniture is relocated between spaces over its life, and partly because a single Crib 5 build-up simplifies procurement and specification. When a client asks for a "contract fire rating" without further detail, Crib 5 is almost always what they mean. Our coated and woven performance ranges are engineered with this benchmark in mind.

Crib 7: the High Hazard rating

Crib 7 is the ignition source BS 7176 assigns to the High Hazard category. It uses a larger wooden crib that delivers a more severe and sustained fire challenge than Crib 5. It is not a general upgrade to be applied "to be safe" — it belongs to environments where the occupancy or fire risk profile justifies it. BS 7176 associates High Hazard with:

• Sleeping accommodation in certain hospital wards and certain hostels — where occupants may be sedated, immobile or otherwise unable to self-evacuate.
• Offshore installations.

Above this sits Very High Hazard, the category BS 7176 associates with prison cells and comparable custodial environments, where deliberate ignition is a recognised risk. In that category the specifier chooses the ignition source, and it may go beyond a single Crib 7 — so a custodial project should never be assumed to be satisfied by a Crib 7 certificate without checking the project fire strategy first.

Because a Crib 7 pass depends heavily on the complete construction, the cover, filling and any interliner must be qualified together.

Which rating do you need?

Use the table below as a starting point, not a substitute for the project fire strategy. The category actually required is set by the responsible person's fire risk assessment, the building's use and the specification — always verify before ordering.

Environment	BS 7176 hazard category	BS 5852 ignition source
Offices, schools, colleges, universities, museums, exhibitions, day centres	Low hazard	Cigarette & match only (EN 1021-1 / -2) — no crib
Healthcare — wards, waiting areas, day rooms	Medium hazard	Crib 5
Hotel bedrooms, restaurants, bars, casinos, public halls, places of entertainment	Medium hazard	Crib 5
Hostels and shared student sleeping accommodation	Medium hazard	Crib 5
Sleeping accommodation in certain hospital wards and hostels; offshore installations	High hazard	Crib 7
Prison cells and comparable custodial settings	Very high hazard	At the specifier's discretion — Crib 7 or more severe

Where furniture may move between spaces during its life, it is common — and sensible — to specify and label to the highest category it could plausibly end up in.

What your certificate actually covers: BS 5852 vs BS 7176

This distinction causes more confusion in tender documents than any other point in this article, so it is worth stating plainly.

BS 5852 is what a fabric supplier certifies. When a Monteiro fabric is tested to Crib 5 or Crib 7, the certificate records that the cover, assembled over a defined filling, resisted BS 5852 ignition source 5 or source 7. That is the document you will receive from us, and it is the evidence a furniture manufacturer needs for the cover component of their build-up.

BS 7176 is what the finished furniture is declared to. Compliance with a BS 7176 hazard category is claimed for the complete seat — cover, foam, interliner and fillings together, with the fillings meeting the UK Furniture and Furnishings (Fire) (Safety) Regulations — and it is the furniture manufacturer who applies the BS 7176 label. A fabric on its own cannot be "BS 7176 certified".

So when a specification asks for "BS 7176 Medium Hazard", what it needs from the textile supplier is a BS 5852 Crib 5 certificate covering the intended build-up; the BS 7176 declaration is then made at furniture level. Ask for both links in the chain, and check that the construction named on the fabric certificate matches the seat actually being built.

Outside the UK: EN 1021 in continental Europe

The BS 7176 hazard categories are a UK framework. Across most of continental Europe, upholstery fire performance is assessed differently.

EN 1021-1 and EN 1021-2 form the foundation of fire safety assessment for upholstered furniture across most of continental Europe. As the reference European standards for ignition resistance, these tests provide a reliable assessment of a material's performance when exposed to representative ignition sources encountered in everyday use — a smouldering cigarette (Part 1) and a match-flame equivalent (Part 2).

While EN 1021 provides the benchmark for many applications, additional and often more demanding fire tests may be required depending on the end-use or target market. Several countries have established their own national standards and regulations, reflecting specific fire safety requirements, such as BS 5852 in the UK and DIN 4102 in Germany — the latter covered in our guide to B1 certification.

Put simply: an EN 1021-1 / -2 pass is a sound indicator of good fire performance and is sufficient for many continental European projects, but it is a baseline rather than a universal answer. As a European manufacturer we test to EN 1021 across our performance ranges — including Mediflex — and hold BS 5852 crib certification and DIN 4102-1 Class B1 classifications on the grades developed for UK and DACH work. Confirm which regime your project references before you procure.

Common mistakes

A handful of recurring errors cause delays, failed audits and unnecessary cost:

1. Confusing a BS 5852 certificate with BS 7176 compliance. A fabric carries a BS 5852 crib certificate; the finished seat is declared to a BS 7176 hazard category. Asking a textile supplier to supply a "BS 7176 certificate" for a fabric is asking for something that does not exist.
2. Treating the crib test as the whole requirement. Every BS 7176 category — Medium and High Hazard included — also requires the cigarette and match-flame ignition tests. A crib pass alone does not complete the picture.
3. Over-specifying Crib 7. Requesting Crib 7 when the hazard category only calls for Crib 5 narrows your fabric choice, raises cost and can slow lead times — without adding compliance value if the fire strategy doesn't require it.
4. Assuming the fabric alone is "rated". BS 5852 certifies a composite. A fabric is only compliant when used over the filling it was tested with; swap the foam and the result may no longer hold.
5. Ignoring the interliner effect. A fire-retardant barrier cloth or interliner can be the difference between a pass and a fail — but it must be part of the tested and specified build-up, not added or omitted informally on site.
6. Not reading the certificate scope. Always check what construction, and which standard, the certificate covers before assuming it applies to your seat or your market.

Monteiro's certified performance grades

We certify our fabrics to recognised contract flammability standards — EN 1021-1 / -2 as our European baseline, with BS 5852 Crib 5 or Crib 7 and DIN 4102-1 Class B1 on the grades developed for those markets — and can supply the supporting documentation for specification and audit. Our Monteiro Performance Fabrics range — including the fire-rated grades within CHANCE 2.0 — is developed for demanding contract environments.

Frequently asked questions

What is the difference between BS 5852 and BS 7176?

BS 5852 is the test method: it defines the ignition sources, including the Crib 5 and Crib 7 wooden cribs, and how they are applied to a cover-and-filling composite. BS 7176 is the specification: it assigns non-domestic furniture to Low, Medium, High or Very High hazard categories by end use and states which BS 5852 sources each category must survive. Fabric suppliers certify to BS 5852; furniture manufacturers declare and label the finished item to BS 7176.

Is Crib 5 the same as BS 7176 Medium Hazard?

Not quite, though they are closely linked. Crib 5 is the BS 5852 ignition source that BS 7176 Medium Hazard requires. Medium Hazard also requires the cigarette and match-flame tests, and requires the fillings to meet the UK domestic furniture fire regulations. A Crib 5 fabric certificate is a necessary part of a Medium Hazard claim, not the whole of it.

Is Crib 5 enough for a hospital?

In the majority of cases, yes — hospitals sit in the BS 7176 Medium Hazard category, which requires Crib 5, and that is what most hospital specifications call for. Sleeping accommodation in certain wards is classed as High Hazard and requires Crib 7. NHS Firecode (HTM 05-03 Part C) recommends Medium or High Hazard according to location, so always confirm against the specification before ordering.

What applies outside the UK?

Across most of continental Europe, upholstered furniture is assessed against EN 1021-1 (smouldering cigarette) and EN 1021-2 (match flame), which are the reference European ignition-resistance tests. They are a reliable baseline, but more demanding national tests may be required depending on the end-use and target market — BS 5852 in the UK, DIN 4102 in Germany. Confirm which standards your project references.

Does the foam affect the crib rating?

Yes — significantly. BS 5852 tests the cover and filling together as a composite, so the foam (and any interliner) is part of what is being certified. A fabric that passes over one filling may not pass over another, which is why a certificate always references the construction it was tested with.

What's the difference between Crib 5 and Crib 7 in plain terms?

Both use a wooden "crib" as the ignition source, but Crib 7 is larger and burns more fiercely for longer, so it represents a tougher fire challenge. Crib 5 is the source required for BS 7176 Medium Hazard — the everyday contract level; Crib 7 is required for High Hazard settings such as certain hospital sleeping accommodation and offshore installations.

Can the same fabric be certified to both Crib 5 and Crib 7?

It can, depending on its construction and the filling build-up it is tested over — but the two ratings are separate test outcomes with separate certificates. Never assume a Crib 5 fabric also meets Crib 7; check the documentation.

Not sure which hazard category your project falls into? Get in touch and our technical team can confirm the appropriate specification, share the relevant BS 5852 and EN 1021 certificates, and send samples of our fire-rated performance grades for your seat build.