Why Is Crib 5 More Difficult to Pass?
For companies accustomed to selling upholstery into the U.S. market, the jump to Crib 5 can be significant.
Common U.S. upholstery requirements such as CAL TB 117 and NFPA 260 use a smoldering cigarette as the ignition source.
Crib 5 introduces a substantially more severe flaming ignition source.
And there’s another important consideration:
You’re not simply testing a piece of fabric. You’re evaluating an upholstery combination.
The cover fabric, foam, backing, interliner, and other components can influence how the assembly performs.
For BS 5852 Source 5 testing, the material is evaluated over filling material meeting the applicable BS 7176 requirements, typically combustion-modified high-resilience (CMHR) foam.
When a fire-retardant treatment is used, water soaking is also required as part of the test preparation.
To meet the Source 5 requirements, the upholstery assembly cannot exhibit unsafe escalating combustion or progressive smoldering and must remain within specified flaming and smoldering limits.
That’s a very different challenge from a cigarette ignition test.
U.S. Upholstery Testing
U.S. Smolder Testing
Ignition
Cigarette
Challenge
Smolder Ignition
Common Standards
CAL TB 117 / NFPA 260
VS.
More Severe Ignition Source
UK Contract Upholstery
Crib 5
Ignition
Burning Wooden Crib
Challenge
Flaming Ignition
Standard
BS 5852 Source 5
A fabric that performs successfully against a smoldering cigarette ignition source may respond very differently when exposed to the more severe flaming ignition source used for Crib 5 testing.