Low Smoke Zero Halogen (LSOH) cables are designed to minimize smoke and toxic fumes in case of fire, making them a safer alternative to conventional PVC cables. They undergo rigorous testing to ensure they meet safety standards, including low halogen content and adherence to specific specifications. While LSOH cables are more expensive than PVC options, their enhanced safety features and long-term cost effectiveness make them a worthwhile investment.

1. Low Smoke Zero Halogen Cable - LSZH or LSOH Cable
Why Use LSOH (Low Smoke Zero Halogen) Cable?
Electrical cables are part and parcel of modern life, without them, we would lose all the luxuries we
take for granted such as lighting, heating and power. Cables, therefore, are essential, but they do
come with drawbacks.
One of the most obvious downsides with traditional cables is that they don’t perform well when
exposed to flames. Cables manufactured with PVC sheathes, for example, create thick, black clouds
of toxic smoke when they come into contact with fire. Accordingly, there’s a need for cables which
are safer and less toxic. Thankfully, LSOH cables deliver exactly this.
What is LSOH Cable?
The main difference between LSOH cables and conventional cables is that the LSOH variety is
designed with a unique thermoplastic jacket. This jacket is designed using a combination of
thermoplastic compounds – usually polyolefin-based – which maximise LSOH cables fire retardant
quality. Most typically, these cables are designed with fire safety and reliability in mind; LSOH cables
provide a perfect solution for cabling in confined spaces which are poorly ventilated. Once exposed
to fire, LSOH cables will produce little to no smoke and ensure that visibility and air quality is not
compromised.
What Are the Testing Procedures for LSOH ?
For a cable to be classified as LSOH , it needs to go through a series of stringent tests to demonstrate
its safety:
 The amount of halogens – which are highly reactive and combustible elements such as
chlorine and fluorine – must make up less than 0.2% of the cable’s weight.
 LSOH cables must adhere to the MIL-C-24643 specifications.
 A PH level of under 3 has to be determined by acid gas testing.
 Details of a cables combined halogen content, acid gas equivalence and smoke release must
be recorded.
 Underwriter Laboratories (UL) testing must be completed to deem the cable as safe to use.
What is the Cost?

2. LSOH cable is not a legal requirement when it comes to dealing with electrical systems. However, it’s
a cable solution which provides significantly enhanced safety, and the benefits are obvious to see.
Financial budgets, of course, are critical when it comes to investing in new components, so it’s
important to understand if LSOH is cost effective.
PVC cables have been in use for over 60 years and remain a budget friendly option, hence why these
cables are found in so many properties. In comparison, LSOH cables are, quite simply, more
expensive. Due to the variety of compounds and associated machine processes, the labour demands
of manufacturing LSOH cables is reflected in the price. Nonetheless, the enhanced safety features of
LSOH cabling means that the additional cost is less a frivolous outlay, and more of an additional
insurance policy for your property. Accordingly, in the long-term, LSOH can be considered highly cost
effective.
Final Thoughts
LSOH cable is a relatively new product in the world of cabling and, as with all products in this
position, the costs of implementing it appear high. However, the enhanced safety more than makes
up for any difference in price when compared to, for example, PVC cables which can quickly become
hazardous when heated. And, as LSOH cable becomes more commonplace, prices will fall in line with
its traditional rivals and offer a fantastic cable solution.
If you would like to know about LSOH cable or want some help and advice, just call us to speak to
one of our team