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The ambiguity of fire retardancy

Tawfiq Atari explains how some clients are often misled by so-called legitimate tests

| | Jun 3, 2015 | 5:52 pm
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Tawfiq Atari explains how some clients are often misled by so-called legitimate tests

Fire safety is an important aspect in the construction industry, and fabrics are among some of the most important materials considered, especially when it comes to public spacing, such as shopping malls, schools and theatres. Public safety is crucial, and steps are needed to reduce the risks as much as possible. In addition to national- or state-level regulations that exist in many countries, many venues develop their own criteria that manufacturers have to pass to prove their product is fire retardant. Adhering to the criteria certifies the products as resistant to fire, either owing to the fire-resistant nature of the material used in the manufacturing process or owing to the fact that they are treated with fire-resistant chemicals during the later stages.

Despite general knowledge, the average person is rarely aware of various standards and regulations in the industry. As a result, there has been considerable confusion about the different fabric fire-retardant certification and test terminologies, and this gap can easily be exploited by some manufacturers, who aim to win customers at any cost.

According to the definition established by the National Fire Protection Association (NFPA) in the United States, fabrics are categorised as Inherently Fire Retardant, “if woven with threads that yield a product that meets fire code standards, without being subject to any special processing or addition of chemicals”. The fibre threads for these fabrics are engineered with flame-resistant properties, embedded into them. “Inherently or Intrinsically Fire Retardant materials remain resistant to flame even after a cycle of 100 repeated washings, because resistance is built into their initial chemical structure, and not chemically added later,” the NFPA says.

In general, even without some certifications, fabrics can offer a basic level of protection, but this is far from sufficient to meet most fabric-flammability standards and building codes. So the problem is that many manufacturers now simply label their items as “fire-retardant”, which can confuse many customers. Although one cannot completely dismiss it as a lie, such terminology is, at the very least, misleading – because all fabrics can be termed ‘fire retardant’, including those woven with threads that failed to meet the fire codes, but have been treated with flame-retardant chemicals, in order to be named as retardant.

The crucial difference is that only fabrics named as Intrinsically Fire Retardant, Inherently Fire Retardant or Permanently Fire Retardant meet the standards that may be used to make some legitimate assumptions about the flame resistance.

Flame Retardant Certification by independent laboratories consists of extensive testing measures that scientifically prove the standards and are impossible to replicate in other environments. UL-2518 is the most widely followed fire-retardancy standard, but not every company can present this evidence.
Instead of simply testing the fabric initially, the test sets higher performance criteria by applying a 100 washing cycles, and only then testing whether it is sufficiently flame retardant and self-extinguishing to meet the standards, or not.

During the testing, a small fabric sample is burned and the flame is measured, together with the char length and the residue. If the required standards are met – the fabric qualifies as fire resistant. If fragments or residues are burning for more than two seconds, if the average weight loss of 10 specimens in a sample is greater than 40% and the weight loss of individual specimen exceeds the mean value of the second set, plus three standard deviations calculated for the second set, the results are recorded as failed.

Providing supposed evidence is a simple but surprisingly effective marketing strategy – the eye is more convincing that the ear. Some have gone as far as simulating a “fire test” in front of the potential client, but real scientific methodology is impossible to replicate.

ASTM E 84 Standard Test Method for Surface Burning Characteristics of Burning Materials measures the relative rate of flame spread and smoke development and is performed in a 25-foot-long by 20-inch-wide chamber. With a photometer and light source placed at the exhaust end of the chamber, the test is run for 10 minutes and the distance and time-rate of flame spread are measured. This is repeated three times with a period of 30 days in between, so unless the manufacturer is able to perform all of the above any conclusions are unscientific and unreliable.

Another important point is the smoke. The NFPA claims that as many as 84.3% of fire-related deaths are caused by smoke inhalation and suffocation, so it is a given that extensive tests focus on smoke development, spread and residue and not just on fire. Replicating a test of this sort is impossible.

The only real evidence of Intrinsic Fire Retardancy is in the form of legitimate test results, repeated over time, which show reliable evidence of fire resistance after continuous performance, including repetitive washing cycles.
So while many suppliers will provide evidence of their fabric meeting fire retardancy standards, the certificates may be outdated, as fabrics that are not Inherently Fire Retardant need to be re-tested on a repetitive basis.

Manufacturers must provide a recent Certificate of Fire Retardancy with UL-2518 results and evidence that fire retardancy remains the same even after a cycle of at least 100 repetitive washings.


 

Tawfiq AtariThe writer is Sales & Technical Director of DuctSox-MENA. He can be contacted at tawfiq@ductsox-mena.com

 


 

CPI Industry accepts no liability for the views or opinions expressed in this column, or for the consequences of any actions taken on the basis of the information provided here.


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