Flammability Tests -7.


Flammability Test Methods:

There are currently no national rules which regulate the requirements either of contract fabrics or the furniture they cover. Instead, regulation is left to local fire officers or building code officials who most often follow one of a number of different models.
California Technical Bulletins (TB)
The State of California is one of the few states to regulate seating products through both mandatory and voluntary requirements.
TB 117 Section E
TB 117 is a mandatory requirement for components of upholstered furniture and Section E looks at a fabric's resistance to a small flame. Fabric mounted at a 45o angle is exposed to a 5/8" (1.6cm) butane flame for 1 second. A pass is achieved if the fabric does not ignite or if the time of average flame spread is 3.5 seconds or longer for a 5" length. Virtually all upholstered fabrics pass this test.

TB 116
This is a voluntary cigarette ignition test for completed items of furniture (or mock ups which simulate a given furniture design) rather than individual fabrics. It requires that lighted cigarettes are placed on all horizontal surfaces which could conceivably support a dropped cigarette - on cushions, arms, base, etc. Three cigarettes are placed in each area, no closer than six inches apart, and a 6" x 6" piece of white cotton or cotton/polyester sheeting fabric is used to cover each cigarette.
A fail is recorded if obvious flaming occurs or if a char develops more than 2" long in any direction from the cigarette.
TB 133
This is another test for completed items of furniture intended for use in "high risk" occupancies - including hospitals, nursing homes, prisons, public areas of hotels, etc. In California it is a mandatory standard in these kinds of occupancy, although there is relaxation of the requirements in areas with sprinklers. The City of Boston has also adopted TB 133, but here it is specified for all non domestic properties and provision of sprinkler systems is not taken into account. The test is very stringent with rigorous pass/fail criteria. It consists of exposing a piece of upholstered furniture to an open flame in a standard room.

The ignition source is a square gas burner placed in the furniture seat, 2" from the back and 1" above the base. The flame exposure time is 80 seconds.
The pass/fail criteria are given below. "Criteria A" were the original parameters and are still acceptable, although "Criteria B" are currently preferred.
Criteria A - A failure is recorded if any of the following occur:- (
i) The temperature measured at the ceiling thermocouple increases by 200oF or more above ambient
(ii) The temperature, measured at the 4ft thermocouple, increases by 50oF or more.
(iii) Greater than 75% opacity at the 4ft smoke opacity monitor
(iv) CO concentration of 1000ppm or more for 5 minutes
(v) Chair weight loss of 3lbs or more during the first 5 minutes.
Criteria B
(i) Maximum heat release of 80kw or greater
(ii) Total heat release of 25MJ or greater in the first 10 minutes
(iii) Greater than 75% opacity
(iv) CO concentration of 1000ppm or greater
Boston Fire Department
Boston adopted California TB 133 in 1995 which virtually eliminated their previous "Boston Fire Test".
The old Boston Fire Code regulated both the flammability of the chair (using a full-scale chair test with a paper bag filled with newspaper as the ignition source) and of component materials, including upholstery fabrics. The fabric test (BFD 1X-1) was a vertical open-flame test using a propane flame applied to the specimen for 10 seconds. Afterflame, afterglow and char length were measured.
New York / New Jersey Port Authority Test
Again, California TB 133 is currently in force for all chairs going into its buildings, but there is also an upholstery fabric requirement for a vertical open flame test.

The fabric specimen is suspended vertically and subjected to a 1.5" methane flame for 12 seconds. Afterflame, drip burn and char length are monitored.
Afterflame: max average 15
seconds Drip burn: max average 8 seconds
Char length: max average 8 inches
"Steiner" Tunnel Test - ASTM E-84 T
his test is best used to assess the flammability characteristics of composites - (ie. upholstered panels) - although panel fabric is more often tested by itself. It is a ceiling fire simulation carried out in a 25 feet long and 2 feet wide enclosure - the "tunnel". Test materials are suspended on the tunnel ceiling and subjected to a 4.5 ft long flame for 10 minutes. The rate at which the flame advances is measured and used to produce a calculated value known as the "Flame Spread Index". At the same time, the opacity of the smoke exiting the chamber is monitored to calculate the "Smoke Developed Index". These two indices are then used by building code officials to classify materials into usage categories.

N.B. The test procedure itself describes neither a classification system nor pass/fail criteria.
The most common classification categories come from the National Fire Protection Association 101 Life Safety Code. There are different requirements for panels listed with Underwriters Laboratories and yet further differences for panels sold to the US government (GSA - General Services Administration).

  U.L. GSA  
Life Safety Code  
  Class A Class B Class C    
Flame Spread 25 max 75 max 200 max 200 max 25 max
Smoke Developed 450 max 200 max 450 max

In general, panel products are expected to meet Class A requirements, though some occupancies have more relaxed standards.

Courtesy: thetextileguide.com