Thursday, December 27, 2012

Low Smoke Zero Halogen Overview

LSZH Jackets

( Smoke image from

Our friends at Anixter published a great whitepaper recently on Low Smoke Zero Halogen (LSZH) in the cabling industry.  If you haven't seen it, it is listed on Cabling Installation & Maintenance's website here.  Of course, we can't say it better than they just did, but we wanted to give a brief overview of what LSZH is for those who work in our industry but don't know much about it (yet). 

LSZH is a compound used to make the jackets of certain signal-grade cables.  Most cables have always been and are still made with a polyvinyl chloride (PVC) jacket.  The PVC used on cables is a soft, flexible, durable plastic material that protects the copper wire within from shorts, corrosion, and most kinks.  It is also relatively cheap, and in most cases has no disadvantages.

So, if you just need a patch cable or a USB cable for a general application, PVC is probably what you'll get and is fine.

However, there are limits to the applications of PVC.  One of these is in poorly ventilated locations where lots of cables may be used in a small area, especially if there may be any difficulty in escaping the location in the event of a fire.  That's because PVC releases dense smoke and toxic gasses when burned. This smoke can quickly obscure the area and can even incapacitate people unable to get out to fresh air quickly.  If you think about it, there are several applications where this would be a factor:

  • Enclosed, windowless rooms with single points of entry, such as a wiring closet in a large building
  •  Military vehicles where occupants may be at risk and cannot exit the vehicle if it catches fire
  • Airplanes and submarine vehicles where it is impossible to get ventilation or get outside in the event of a fire
  • Underground locations like tunnels, subway platforms, and mines

How to Get LSZH Cables

If you are installing or integrating cabling, especially dense cabling or multiple cables in a small area, in one of those applications, you may want to price out LSZH alternatives even if they are not strictly required by the specifications of the job.  L-com carries a variety of LSZH bulk cable and cable assemblies, including:

LSZH Cable Assemblies LSZH Bulk Cable



Telecom and Ethernet

Fiber Optic




Telecom and Ethernet



Quick note: If you are interested in more articles about LSZH, L-com has published several in its newsletter archive section here.  Articles include "LSZH USB Cable Assemblies", "PVC, LSZH, and Polyurethane: Know your cable jacket choices", and "LSZH for Data Cables".  You can also sign up for free to get the email newsletters each week.

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