Clearing Up Confusion About Flame Retardant Textiles from Steve Schneider of Schneider Textile Finishing Inc.
ln the world of flame retardant fabrics there are many codes that a fabric can pass and many ways in how a fabric can be treated to pass the requirements necessary for installation in even the areas that have the strictest fire code regulations.
Because there are so many different fire codes it is important to know what the fabric is to be used for. The easiest tests to pass are those used for furniture dress covers in public buildings or in the case of California, furniture in homes. These tests are called cigarette ignition tests. There are three tests that are used in almost all cases. These three tests are the NFPA 250 Specifications, The California Technical Bulletin #117 Specifications and The UFAC Class I Specifications. (UFAC Stands for Upholstered Furniture Action Committee).
ln this test a burning cigarette is used in a crevice of the seat and back junction to try and ignite the fabric. lf the fabric catches fire or there is a char length from the cigarette more than one inch the fabric is classified as a failure and does not pass. lf the char length is less than one inch the fabric does pass the test and is certified as passing. These three tests are from different governing bodies but the test procedure for each of the three tests is the same. lf a fabric passes any one of the tests then it passes all three of the tests.
Because this is a cigarette ignition test, in order"for the fabric to pass it cannot smolder. Most synthetic fibers like polyester, nylon and others as well as silk and wool pass these test inherently with no treatments added. lt is the natural fibers like cotton and linen that smolder and fail the tests. Chemical treatments can be used to have the fabrics that fail the test become compliant with no issues.
These tests are discussed here because so many fabric vendors can state on their spec sheets or true tags that the products does pass these tests and that may lead to confusion as this does not mean they can be used as draperies or in a vertical position in a public setting.
There are two tests most commonly used for fabrics in a vertical position. These are the NFPA 701Specifications and the California Title 19 Specifications. In the NFPA 701 test the fabric is tested in a vertical position in which the test specimen is placed over a Bunsen burner for 45 seconds. The Bunsen burner is then extinguished and the fabric is observed to see if it self extinguishes in 2 seconds or less. The test sample is also weighed before and after it is burned and it may not lose more than 40% of its original weight after it is burned.
The California Title 19 test procedure is also a vertical test similar to the NFPA 701 test but it will have 4 seconds to self extinguish and there is a measurement of the char length in the Title 19 requirements that must be under 6 inches long.
These are difficult tests to pass as they are both meant to determine that the fabric can not support combustion on its own. Very few textiles will pass vertical open flame tests without some addition of Flame Retardant chemical. Fiber Glass and Nomex are two fibers that do pass these tests without further treatment.
This then brings the attention to how fabrics are made to meet these tests. There are several ways a textile can be made to become compliant with these requirements. The first one is the manufacturing of inherently flame Retardant polyester. ln this process a flame retardant is added to the polyester before the yarns are extruded. ln this case the flame retardants is an actual part of the yarn. lnherently Flame Retardant polyesters can be either launder or dry cleaned for as long as they last. There is no loss of the Flame Retardant properties when this fabric is cleaned in any way.
For fabrics that are manufactured of yarns that do not have this inherently flame retardant polyester a chemical treatment must be added. Not all, but most fabric can be treated successfully to pass the NFPA 701 and California Title 19 specifications. This process should always be done by a professional as different chemicals should be used on different fibers and there are considerations to be made on such things as dyes and where the fabric is to be used. Most chemical treatments cannot be laundered. The Flame Retardant chemicals used by most all treatment facilities are water soluble and non toxic in every respect. lt is because the chemicals are water soluble that water even in small amounts will remove the flame retardant chemicals in the fabric. ln most cases fabrics that have been treated to pass the codes can be dry cleaned in pure solvents only with no loss of Flame Retardancy.
While a treated fabric can remain flame retardant for the life of the fabric if it is kept completely dry it is prudent to test fabrics for flame retardancy on a regular basis. This can be done with what is called the NFPA 705 field test. ln this test a sample is cut from an unseen area of the cloth and then put in a vertical position and lit with either a cigarette lighter or two kitchen matches. lf the test fabric does not burn for more that 2 seconds after the source flame is taken away the fabric is still flame retardant.
This is important to note because there are many safe non toxic flame retardants that have been used over the years for fabrics and there have been chemicals used that do disintegrate over time even though the fabric never got wet. While seeing these chemicals in 2019 is rare it is never the less a possibility that they may have been used.
There are other flame retardant codes for textiles that are used on aircraft, cruise ships, automobiles and RV's. This information is provided as general information for textiles used in an interior setting in the public space venue. More detailed information would always be available through your fabric vendor or finisher.