EuroWire November 2015

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Technical article
November 2015 49
Fire Risk and Safety
Philosophy in Indoor
Cabling
By Jörg Bör
Abstract
The fire performance of cables is a very
important issue, especially in indoor
cabling. On the one hand cables must
not ignite by their own in case of any
perturbance. But in most cases cables
connect different rooms or devices with
each other. Thus on the other hand fire
propagation is no less important than
self-ignition. Thirdly, fire ratings are
defined for safety relevant applications.
IEC 60331 specifies a period of time during
which the intended performance has to
be maintained while a permanent flame is
burning the cable.
Although this knowledge is common,
experts often wonder why fire perfor-
mance requirements seem to be weak in
some regions. But the understanding of
the specific fire safety philosophy leads to
understanding the different approaches to
achieve fire safety in different countries.
Every risk is defined as the product of
two factors: one is the probability of
an accident and the other is the extent
of damage. The risk is quantified by
multiplication of these factors. This is the
same for the risk of fire.
In some countries fire safety philosophy
focuses exclusively on the avoidance of
any fire. So the target is to reduce the
probability of fire close to zero. In other
regions both factors of risk are considered.
Thus the burning characteristics are much
more important. If a fire appears, negative
effects on the health of persons or
technical goods shall be as low as possible.
This includes the aspects of corrosive
fumes, which may transform to acids by
reaction with any water, as well as the
reduction of smoke density, which might
cause bad sight in case of fire and confuse
any people looking for emergency exits.
For this reason, the criteria “halogen free”
and “low smoke” are much more important
in Europe than, for example, in America.
Halogens there are used especially for
fire avoidance, because these elements
have self-extinguishing effects. The highly
reactive elements of the 7th principal
group collect oxygen and help to stop
a fire. But compounds of halogens with
oxygen are acid radicals, which react with
the omnipresent water and turn into an
acid. These corrosive smokes are a danger
for personal health and might damage
technical goods as well.
This paper discusses the different
approaches of fire safety, threats and
advantages.
1 Introduction
American experts often ask why European
countries have weak fire protection
regulations. On the other hand European
people wonder why Americans are not
aware of the tremendous danger of acid
smoke caused by halogen fumes. This
difference is often discussed between
experts in standardisation committees
as well as with customers in cable sales
presentations.
Looking at European fire safety
regulations, for example the “Constructive
Products Regulation” (CPR)[6], may
be confusing. Why don’t European
governments protect their inhabitants
better against the risk of fire? Looking
at American fire safety regulations does
not confuse less: Why don’t American
governments protect their people against
the risk of acid fumes?
In a democratic world, laws and
regulations are not given to the people,
but are made by the people. Laws and
regulations are a result of the general
public opinion and mentality. In a business
market it should not only ask for standards
and regulations but for the ideas behind
them. Neither customs nor any other trade
barriers prevent the sales of American
products in Europe and vice versa, but the
missing acceptance of those products by
the final consumer.
2 Intercultural
Differences
The first step of knowledge of intercultural
understanding is the experience that
there are differences. The second step is to
recognise that these differences cannot be
evaluated to be better or worse, but just
different.
The reasons for intercultural differences
cannot be investigated in this paper.
Intercultural differences are often
established by historic experience or by
the influence of the geographic situation.
Deeper explanations are given in the
appropriate literature.
One might think this might be an issue for
typical consumer markets (B2C) but not in
markets of industrial goods (B2B). But be
aware, the managers in the B2B market are
often women or men born in that specific
region and living there, and they have
to take into account the requirements of
their selling markets which are usually in
the same region. Hofstede[1] names this
“cultural relativity”.
Several publications by social scientists
as well as by economic scientists show
the huge regional difference regarding
different parameters. Hofstede[1] defines
the five parameters power distance,
uncertainty avoidance, individualism,
masculinity, and long-term orientation.
The detailed meaning of these parameters
is explained in his paper[1] , but the regional
difference can be demonstrated in general
without detailed understanding of these
parameters (Figure 1).
All these parameters are scaled from zero
to 100. A value close to zero means the
opposite position is extremely strong. So,
for example, an individualism factor of
three means collectivism is in high gear.
Keeping in mind that there are huge
regional differences regarding cultural
relativity, it is easy to understand that in
every region of the world, safety feelings
and safety needs are different, too.