Time To Clarify Some
Misconceptions
By Robert Bellassai
There is a lot of confusion in the industry regarding claims,
mostly self-certifi ed, of low-smoke, halogen-free cables
and the materials T
used in these cables. HERE IS A LOT OF CONFUSION
in the industry regarding claims,
mostly self-certifi ed, of lowsmoke,
halogen-free cables and
the materials used in these cables.
Product claims about lowsmoke,
halogen-free (LSHF) —
also known by the industry as
low-smoke, zero-halogen (LSZH)
— have been with us for some
36 | Mass Transit | MassTransitmag.com | JUNE 2017
time now. Of note, these claims are
frequently self-certifi ed and tests
used may not be standards-based.
More importantly, there are some
misconceptions about what some
tests actually cover, which this
article aims to clear up.
LSHF products originated in
Europe and the United States in
the 1970s. In the 1980s they were
used in applications, such as the
London Underground, U.K. Navy
and North Sea off shore oil drilling
platforms. LSHF cables were
installed in confi ned
spaces where
the toxicity
LSHF CABLES are being used in
more locations.
and corrosivity of the smoke generated
in a fi re would be particularly
problematic. Th e adoption of LSHF
cable products has been slow in the
U.S., but that has changed due to
some high-profi le fi res. A key example
is the Jan. 12, 2016 L’Enfant
Plaza incident in Washington, D.C.,
where an electrical malfunction fi re
fi lled a tunnel with smoke, killing
one person and injuring others.
LSHF cable products have traditionally
been found in the power
and control categories, but now
have branched out to categories
including data/telecom cables, fi -
ber optic cables and appliance wire
and cable. Th ey also are being used
in more locations than the traditional
confi ned spaces (tunnels,
subways, ships, submarines and
mines), and are now also found
in hospitals and data centers. UL
will be proposing the optional HF
and LSHF Marking for the 2020
National Electrical Code (NEC)
revision cycle.
Asia and South America are
also adopting LSHF wire and
cable, which has been the EU
approach to cable standards. In
a global economy manufacturers
now have access to a standards
based LSHF cable designation,
cable designers can produce
one design that can be sold and
applied around the world.
To better understand LSHF, we
need to consider what a halogen
is in terms of the Periodic Table
of Elements. Th e fi ve halogen elements
found in column 17 are
fl uorine, chlorine, bromine, astatine
and iodine. Th e three primary
elements found in insulation, fi ller
and jacket materials/components
are chlorine, bromine and fl uorine.
Four predominant wire and
cable industry standards — IEC
60754-1, IEC 60754-2, IEC 61249-
2 Non-halogenated series and MIL
DTL-24643C Part 3.3 (NEMA
WC57) — continue to be the
source of some of the confusion
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