Posted on August 24 2015
Confusion reigns in the marketplace regarding what is and what isn’t Flame Resistant Rainwear. For years Federal Test Standard No. 191A method 5903.1 was used to test materials. When tested, if those materials exhibited a flame and afterglow less than 2 seconds and a char length less than or equal to 6 inches after the ignition source was removed, they were considered Flame Resistant.
Things began to change in the late 90’s with the development of ASTM F1891 the Standard Specification for Arc and Flame Resistant Rainwear and the elimination of Federal Test Standard No. 191A method 5903.1. The latter was replaced with ASTM D6413 which is the same test method but there are no written pass or fail criteria with it although most companies still reference an after flame less than 2 seconds and a char length less than or equal to 6 inches to promote a rain suit as FR.
The difference in performance between a garment that meets ASTM F1891 and a garment that is tested to ASTM D6413 and passes the accepted criteria is dramatic. For those who are simply looking for a garment that will not catch fire and continue to burn if the flame source is removed, like a welder hit with slag, a D6413 garment may be fine. For anyone with the potential of being exposed to an electric arc or a flash fire it is not.
ASTM F1891 was published just after ASTM F1506 the Standard Performance Specification for Flame Resistant and Arc Rated Textile Materials for Wearing Apparel for Use by Electrical Workers Exposed to Momentary Electric Arc and Related Thermal Hazards. Although both utilize the same test method and require similar levels of performance, ASTM F1891 specifically addresses the needs of rainwear while F 1506 is intended for clothing.
The market continued to advance in 2001 with the release of NFPA 2112 the Standard on Flame-Resistant Garments for Protection of Industrial Personnel against Flash Fire. Although this standard relates to clothing and not rainwear, it began to increase the awareness for products that perform in the petrochemical and gas utility markets rather than just electrical markets.
In 2009, ASTM F2733 the Standard Specification for Flame Resistant Rainwear for Protection Against Flame Hazards was published to meet the needs of those who required flash fire rainwear. Similar to the flame and arc standards, ASTM F2733 and NPFA 2112 both utilize the same test method, and require similar levels of performance but ASTM F2733 takes into account the uniqueness of rainwear materials.
ASTM F2733 establishes test methods and thermal performance criteria for rainwear worn by workers who may be exposed to industrial hydrocarbon fires or other petrochemical fire hazards. The standard is intended to ensure workers wear rainwear products that are designed to increase survivability by lowering the percentage of body burn and burn severity from a 3 second flash fire.
In summary, if you are looking for a rain suit with no thermal protection that may melt and drip if exposed to a flame source but won’t continue to burn for more than 2 seconds after the flame source is removed, look for garments tested to ASTM D6413. Marketing materials associated with those garments should state the 2 second flameout and char length less than or equal to 6 inches.
If you are looking for a rain suit to protect you from an electric arc or one that offers similar protection to ASTM F1506 compliant clothing, then you want a rain suit that is compliant with ASTM F1891.
If you’re wearing NFPA 2112 compliant clothing, then you should be looking for rainwear that meets ASTM F2733 which is specifically designed for flash fire protection or dual hazard products that provide protection against both arc flash and flash fires.
The recent ANSI 107-2010 Standard takes a stance against melting and dripping textiles. However, the requirements for labeling can be difficult to understand and lead to misinterpretation. The Standard states that you cannot indicate “FR” on the ANSI label if the fabric does not meet 1 of 7 FR test methods identified in the standard. The problem is, there is nothing prohibiting a manufacturer from putting an FR label next to the ANSI label (or anywhere else on the garment).
So what should a user or your customer look for? If you don’t want the garment to melt or drip and the textile content is polyester, don’t buy it. Approximately 95% of all ANSI high-viz garments are polyester. If the “FR” letters appear on the ANSI label then chances are you are buying a Fire Resistant garment with material that meets the FR requirements outlined in the ANSI Standard. If the “FR” letters don’tappear on the ANSI label then our advice is this… Buyer beware and stay clear of these products.
Originally published in BIC Magazine, July 2014
Written by Brian Nutt, Senior Product Manager, Tingley Rubber Corporation