There is a lot of confusion in the industry regarding claims, mostly self-certified, of Halogen Free (HF), Low Smoke Halogen Free (LSHF), Restriction of Hazardous Substances (RoHS) and Acid Gas (AG) compliant cables and the materials used in these cables. In this article, we will describe UL’s green wire & cable programs addressing these concerns.

Halogen-Free (HF) & Low Smoke Halogen Free (LSHF)

In 2015, UL published the Outline of Investigation for Acid Gas, Acidity and Conductivity of Combusted Materials and Assessment of Halogens. The test method described for the Assessment of Halogens was based on IEC 62821-1/-2 standards. It’s critically important that industry has standards-based certification and testing practices (i.e. HF & LSHF cable designations). Cable designers can use one set of requirements for their designs that can be sold and applied around the world and do not rely on self-declaration/certification. Even more importantly, the end-user has no confusion as to what requirements apply.

Historically, the use of LSHF or HF cable products has been required for military and other specific closed space applications including tunnels, subways, ships, submarines and mines as well as hospitals and data centers. The use of LSHF and HF cable products in these applications is due in part to the toxicity and corrosivity of the combustion product properties associated with halogenated materials. UL has recently observed the industry’s interest in demonstrating that their wire and cable products are LSHF compliant for applications beyond these historical uses, including end-product power and control.

Regionally, the use of LSHF cables has long been the norm in the European Union (EU) where, for example, XLPE, TPE and EVA are commonly employed as halogen-free insulating and jacket materials.

Asia and South America are now beginning to employ low smoke halogen-free cable constructions at a greater rate as evidenced by an increase in manufacturers in these regions seeking UL HF and LSHF certification.

UL has recently changed our Assessment of Halogens test method. The original method was a four-stage indirect measurement and has changed to a direct measurement of Fluorine, Chlorine, Bromine and Iodine with a 1000 ppm maximum limit for each halide. UL has changed the UL2885 method for the assessment of halogens, to be more aligned with the new IEC 60574-3 standard. This test method change also addresses possible false positive and negative results obtained when using the four-stage method.

An Industry File Review (IFR) has been announced with an effective date of January 1, 2021. For the IFR, UL has offered two options for our clients; formulation review (with possible some testing) or testing impacted material to the new method.

Since 2015, UL has provided an HF material Recognition program and an optional HF & LSHF cable Mark. These programs continue to be very successful as they as their requirements are based on international standards (IEC). UL has issued many certifications to date and UL’s HF/LSHF Mark will be noted in the US 2020 National Electrical Code (NEC) NFPA 70.

Restriction of Hazardous Substances (RoHS)

UL’s Restricted-use Substances (RoHS) material Recognition program evaluates compounds and components to be used in RoHS approved wire and cable.  

UL has recently announced our RoHS wire & cable surface Mark certification program. Wire and cable manufacturers now can apply the optional “-RoHS” suffix to Listed and or Recognized type designations (e.g. Type TC-RoHS, CMR-RoHS, SJT-RoHS, etc.) for products that comply with the RoHS directives. This program evaluates compounds and components used in any UL Listed or Recognized wire and cable constructions to ensure that they comply with the maximum allowable substance concentration thresholds specified in the European Directives for restricted substances:

  • DIRECTIVE 2011/65/EU OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 8 June 2011 on the restriction of the use of certain hazardous substances in electrical and electronic equipment (recast).
  • DIRECTIVE (EU) 2015/863 of 31 March 2015

Compounds and components are evaluated to UL746R for nonmetallic materials and UL1368 for metallic components.

Individual compounds and components may be Certified under our component Recognition program by the supplier or by the cable manufacturer if their supplier has not submitted for RoHS certification.

Acid Gas (AG)

In addition to Fluorine, Chlorine, Bromine and Iodine, many chemical elements may cause toxicity and corrosivity of combusted products. Some of these elements are Sodium, Phosphorus, Nitrogen and Sulfur. As a result, an HF and or LSHF rating may not be enough to ensure a wire or cable’s “green” characteristics.

This concern had been addressed in UL 2885 which is developed partly based on the following IEC industry standards, specifically Test on gases evolved during combustion of materials from cables – Part 1: Determination of the halogen acid gas content in IEC 60754-1 and Test on gases evolved during combustion of materials from cables – Part 2: Determination of acidity (by pH measurement) and conductivity, IEC 60754-2.  

Under UL’s compound and component material Recognition program, suppliers can certify their products for compliance for IEC 60754-1 and/or IEC 60754-2. If these products are not UL Recognized for compliance to these IEC standards, the cable manufacturer can also certify material in their cables to the standards.

In addition to the IEC standards mentioned above, the new Acid Gas 14 (AG14) Mark has been developed. All nonmetallic compounds and components contained in the wire or cable construction are evaluated to the Acid Gas Emission test in accordance to UL 2556. A maximum acid gas requirement of 14% by weight when calculated as HCl is applied to comply.

Wire & Cable manufacturers now can optionally Mark cables where each combustible compound and component meets the maximum 14% requirement when the Acid Gas Emission is tested in accordance to UL 2556.

Please visit for additional information. To submit a product for testing or certification to any of these programs, please contact Robert Bellassai at UL’s office in Melville, New York, tel. 631-546-2871, or David Cavassa in France, tel. +33 666 013 192,

Image source: UL

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