Fire compliance is a composite problem, not a fabric problem

Upholstered seating passes or fails fire testing as a composite: cover, interliner and foam together. A cover that passes alone can still fail once it sits over the foam you chose, which is why the report has to name the whole build.

Published by JPChairs · Chair manufacturer in Foshan, China · 2026-10-15

The four standards that appear in a tender

• California TB117-2013 — the US residential and hospitality default. A smouldering cigarette test on the finished composite with no open flame, covering roughly 80 per cent of US enquiries.
• BS 5852 Source 5, or Crib 5 — the UK contract standard for hotels, restaurants and public spaces. A 20 g wooden crib is ignited in the seat and the composite has to resist flaming and smouldering.
• BS 5852 Source 0 and 1 — cigarette and simulated match. Often quoted, but Source 5 is what UK contract specifiers actually demand.
• EN 1021-1 and EN 1021-2 — cigarette and match equivalent, the European furniture reference, usually paired with an EN 13501-1 classification for the finished item in a public building.

Establish which one applies before you ask for a price. They are not interchangeable, and a cover sold with a TB117 report will not automatically carry a Crib 5 result.

What the tests actually measure

Every one of these is a composite test run on a rig that reproduces a seat-to-back junction, because that is the hottest point on a chair and where cover, interliner and foam interact.

• Cigarette test — a lit cigarette is placed in the junction and left for up to 60 minutes. Pass means no flaming and no progressive smouldering after that hour.
• Match equivalent — a small butane flame applied for 15 to 20 seconds. Pass means no flaming once it is removed and no smouldering at 60 minutes.
• Crib 5 — a wooden crib of 20 g, plus or minus 2 g, burned in the junction. Flaming must not persist beyond 10 minutes after the crib is consumed, and smouldering must not persist beyond 60 minutes.

The margins are not generous. A build that scorches but does not ignite still fails if it keeps smouldering into the second hour.

Inherent FR versus treated fabric

• Inherent FR, such as Trevira CS or modacrylic blends — the resistance is in the fibre. It survives 50 industrial washes, keeps its hand, and costs USD 18 to 40 per metre. Nothing to reapply and nothing to disclose.
• Topically treated fabric — a standard polyester or cotton blend with an FR back-coating at USD 6 to 15 per metre, a 30 to 50 per cent premium over the untreated version. The hand stiffens slightly and the finish can migrate; plan on 5 to 10 dry cleans before retreatment is considered.
• FR interliner — a barrier layer between cover and foam at USD 3 to 8 per metre. It lets a non-FR cover pass a composite test and is the cheapest route to Crib 5, but it stiffens the seat and adds 1 to 2 mm to the build.

At 0.6 m of fabric per restaurant seat, an inherent FR upgrade adds roughly USD 12 to 25 per chair and an interliner roughly USD 4 to 10.

Foam and interliner decide the result

Standard polyurethane at 25 to 30 kg/m³ will fail Crib 5 under most covers. Combustion-modified high-resilience foam, CMHR, at 30 to 35 kg/m³ is the baseline for UK contract work and adds 15 to 25 per cent to the foam cost.

Three builds pass reliably: inherent FR cover over CMHR foam; treated cover over CMHR foam; non-FR cover plus FR interliner over CMHR foam. What does not pass is a non-FR cover straight onto standard foam, which is the default build unless you specify otherwise.

Specify the build rather than the fabric: cover reference, interliner reference, foam type and density, and the standard being tested to. A report missing any of those four names something you did not order.

Certificates: what to ask for

• Test report, not a certificate of conformity. The report names the composite, the laboratory, the standard and the date.
• The exact composite. Cover, interliner and foam referenced by product code. If the report lists a foam you are not buying, it does not cover your order.
• Date within 12 to 24 months. Most UK contracts and insurers treat a report older than three years as expired, and many require a retest every 12 months.
• Batch traceability. Mill batch number tied to the purchase order, so a failed retest can be traced to a dye lot.

Retesting costs USD 300 to 700 per composite and takes 10 to 15 working days. Build it into the programme rather than discovering it at handover.

Cost and schedule impact

FR compliance adds 10 to 15 days to a standard upholstery schedule, almost all of it fabric procurement: inherent FR lines carry 300 to 500 m minimums per colour and 15 to 25 day mill lead times when not held in stock.

Per chair, at 0.6 m of fabric and a 0.03 m³ foam cut: USD 12 to 25 for inherent FR, USD 4 to 10 for an interliner, USD 3 to 6 for CMHR foam. On a 300-chair hotel order that is USD 5,700 to 12,300, roughly 1.5 to 3 per cent of a typical seating package and far less than a failed inspection at handover.

The upholstered frames these composites are tested on are in the upholstered dining chairs, and the sample and approval route for a tested build is on the OEM sampling process.