This article contains my technical opinion and is for general information purposes only.

What are LSZH cables? 

In a fire, the largest risk to both people and property is often smoke and toxic gases. Cables with conventional jackets like PVC may emit a lot of smoke and toxic halogen gases when burnt. When inhaled, smoke and toxic halogen gases can be fatal. Halogen gas emissions can also be corrosive to equipment contacts and electronics. Low Smoke Zero Halogen or LSZH cables are designed to emit low levels of smoke and zero or low levels of halogens when the cables are burnt.

LSZH cables are commonly used overseas in IEC projects for power and control applications.  Specification of LSZH cables has gradually become more common in North American applications. In Canada, they have been used in new and retrofit tunnels, underground confined spaces, shipboard, and transit projects. Additionally, some industrial projects have specified LSZH cables for use in control rooms and data centers to protect both people and sensitive equipment.

CSA LSZH cables are not typically stocked products in Canada. These products are commonly made-to-order with minimum order quantities and lead times. Although these cables are safer alternatives to cables conventionally used in Canadian projects, the lack of inventory has limited their use to applications where they are required by codes and standards. 

As Canadian specifiers see more customer requirements asking for LSZH cables, many are uncertain which products meet their project requirements. There are a lot of cable standards and burn tests, each resulting in different allowable smoke and halogen levels.

Terms like LSZH, LSHF (low smoke halogen free), FT4 ST1 (ST1 is a smoke test), LSOH (low smoke zero halogen) are all commonly associated with cables designed for low smoke and halogen applications. However, they may be built to different test requirements. As such, you may wish to confirm the test and standards for a given LSZH cable to ensure that it would be a good fit for your application’s smoke and halogen requirements.

Feel free to contact your Texcan Representative to select the best product options for your low smoke zero halogen applications. See our product lines of VITALink® 2HR Life Safety Cables for an example of an LSZH jacketed cable.