Crib 5 Fire Ratings Explained

What "Crib 5" actually refers to

"Crib 5" is shorthand for the highest ignition source in BS 5852, the British Standard test for ignitability of upholstered seating. The test uses a small wooden crib (a stack of sticks) of a specified size as the ignition source; Crib 5 is the largest of the five crib sources, and upholstery that passes it has demonstrated resistance to a substantial flaming source, not just a cigarette or match.

The rating is applied to the combination of cover fabric and filling together, not fabric alone. That's an important distinction: a "Crib 5 fabric" quoted by itself is not the whole story: the foam, interliner and composite assembly all influence the pass. This is why contract upholstery suppliers quote a "Crib 5 composite" with a specific fabric-and-foam combination on the certificate.

Where Crib 5 is required in the UK

Crib 5 is specified via BS 7176, which categorises environments by their level of fire hazard. Broadly, the environments where Crib 5 (BS 7176 "high hazard") is the expected level include:

• Hotels and guesthouses: bedroom and public-area upholstery
• Student accommodation / halls of residence
• Hospitals, care homes and nursing homes
• Public buildings with overnight use or restricted egress
• Some prison, custodial and ministry-of-defence environments

BS 7176 also defines "medium hazard" (Crib 5 in most public-area upholstery), "low hazard" (offices, schools) and "very low hazard" (most domestic). For commercial office furniture in typical UK workplaces, BS 7176 low-hazard is the usual specification, which is a match-and-cigarette test (BS 5852 ignition sources 0 and 1), not Crib 5.

What documentation you should keep on file

For any contract upholstery subject to BS 7176, your supplier should provide a test certificate that names the fabric, the foam, the interliner (if used) and the crib level passed. The certificate should be issued by a UKAS-accredited test house. If you're procuring into a regulated environment, your insurer or licensing authority will often want to see:

• BS 7176 / BS 5852 certificate for each upholstery composite
• Statement of the hazard category the furniture is rated for
• Date of test and validity notes (some certificates are time-bound)
• Matching labelling on the furniture itself (fire-retardant label, batch number)

Common mistakes we see

The most frequent issue is clients buying a chair rated for low-hazard use and then installing it somewhere that legally requires medium or high-hazard compliance. The chair doesn't fail physically; it fails the paperwork test on an insurance audit or a fire officer's site visit. The second most common issue is re-upholstery changing the rating, if a client has a Crib 5 chair reupholstered in a non-rated fabric, the Crib 5 certification no longer applies to the new composite.

The third issue is bespoke: if a piece has been made to a custom specification (say, a restaurant banquette in a client's own fabric), the composite needs to be tested, not assumed. A reputable supplier will flag this up front rather than after delivery.

What this means for your project

If you're specifying hospitality furniture or education furniture for student accommodation, assume Crib 5 is required unless explicitly told otherwise, and ask for composite-level certification at quotation stage, not at delivery. Every piece of upholstery we supply into regulated environments comes with the full fire, safety and test documentation needed for your records, insurer and audit trail.