There is a lot of confusion regarding the terminology, definitions and tests/standards related to optional markings commonly used and /or claims associated with specialty cables, which include LSZH (low smoke zero halogen free), non-halogen, HFFR (halogen free, flame retardant) and LSF0H (low smoke and fume, zero halogen).
A few years ago, the International Electrotechnical Commission (IEC) developed requirements around the term low smoke halogen free (LSHF) as described in IEC 62821-1/-2/-3. The requirements in this IEC standard series describe methods to determine the halogen content in all combustible materials used in the construction of a cable, the smoke generation of the entire cable and most importantly, a cable surface mark directly linked to these test methods, as described in the IEC standard.
Since the release of the IEC standard, UL has developed our HF and LSHF material Recognition and cable Mark Certification programs, respectively. Material suppliers and cable manufacturers now can apply standards-based surface print marking that attest to compliance with these requirements, backed by the globally trusted UL Mark.
The inclusion of the optional HF and LSHF markings in various articles in the 2020 the National Electrical Code (NEC), recognize the widespread use and importance of such markings in conveying relevant information about cable properties to installers and AHJs. Halogen free materials are taking on increasing importance in specialty installations involving spaces with reduced ventilation capabilities such as elevators, subways and mines. Internationally, there are an increasing number of regulations restricting the use of halogenated materials, resulting in growing use of halogen free cables and their associated markings. As a result, the NEC has included the halogen free and low smoke halogen free surface marking definitions in Articles 725 and 805 with applicable test standards in the 2020 edition.
The addition of applicable surface marking terminology avoids misuse of cable markings and performance. These examples clearly define the performance criteria for evaluated products.
The proper use of appropriately Marked and Certified specialty cables enhances safety and reduces misinformation.