The short answer is, “‘Self-extinguishing’ means nothing for flash fire or arc flash.”
Actually, because it could imply that the materials will “self-extinguish” safely in all conditions, we consider this term deceptive and dangerous.
“Self-extinguishing”, or “SE”, is a relatively new term. “SE” is a marketing term used only by a few companies. No standard exists that requires testing to label something as “self-extinguishing.”
Usually, if “SE” is on a product label, that particular product has been tested ONLY in a small-scale vertical flame test. In those cases, the product has not been vetted well enough for an arc flash or flash-fire hazard. This idea used to be called “FR”, but flame resistance has come a long way since the 1950s.
Basically “SE” is usually nylon or polyester or a coated version of this which has been FR treated to suppress flame. This works for VERY small-scale flames, but the material will still melt and drip under most arc flash or flash fire conditions. Some chemical suits and many high-visibility vests use this type of system. DO NOT believe that these suits will always extinguish in a large-scale exposure.
OSHA has been asked about the term “self-extinguishing”. We are waiting for their response.
Limitations of SE
The idea of treating melting materials to slow down or arrest small-scale flame propagation is NOT a bad idea, but end users should be adequately warned about the limitations of this type of treatment.
For years we have taught people that these materials can become airborne molten plastic and fly onto the exposed skin of workers or melt into the skin. If a worker is using a high-vis vest on a road crew and the only flame hazard is a portable heater flame, this garment may be adequate. If someone is wearing welding protection and wears a high-vis vest on a bridge, this could work IF the worker is adequately covered to prevent melting of the material onto the skin.
Flash fire and arc flash exposures will never want one of these vests, especially these rainwear materials.
Conformity to ANSI 107
Hi-visibility arc-rated outerwear, including rainwear, should conform to the requirements of the ANSI 107 standard. ANSI 107-2015 details the performance requirements for all materials used in the construction of compliant high-visibility safety apparel (HVSA). It also specifies labeling requirements to identify the garment by performance class, type and its flame resistance characteristics as defined in the standard.
What You Should Know
When purchasing outerwear Personal Protective Equipment for a specific site or company, know the hazards the workers face. It is important to protect workers adequately from the known hazards, meaning they should wear appropriate PPE – not too little and not too much. Once you know the hazards, find out what products are available.
To avoid waste (in time and money spent needlessly), learn what the correct labels will say on the items of clothing that need to be purchased. For arc flash clothing in the US, look for ASTM F1506 or ASTM F1891 for rainwear. For flash fire hazards, NFPA 2112 is appropriate for garments, hoods/shrouds/balaclavas, and gloves. ASTM F2733 is appropriate for rainwear.
To label a product “FR” per ANSI 107, the product must be tested to one of the following specs (and the supplier should have proof):
ASTM F2302 is listed in the standard but has been withdrawn because I convinced the majority of the committee that some products could pass this battery of two tests and still be dangerous (especially in the form of rainwear).
Learning about the test methods and standard requirements can be daunting and time-consuming. Knowing everything is not necessary at the beginning. But knowing correct labeling is important.
For help in finding out more about different standards, visit Arcwear.com.
- and what work situations they apply to
- List of standards and guides to point you in the right direction
- You can find a list of PPE suppliers on the Arcwear website. These are our customers or former customers who to date have shown themselves to be reliable in their control of FR and their testing. If ANY supplier on our list is suspect, please contact us at arcwear.com with the evidence and we will remove them if they are not doing the right things.
You may also enjoy reading about arc-rated PPE in hot weather.