|Fire safety or the environment - is it necessary to choose?|
Issue 48: Fire safety or the environment - is it necessary to choose?
By Margaret Simonson McNamee
Awareness of the fact that large fires may present dramatic and
persistent adverse effects on the environment has risen since the
occurrence of numerous high impact incidents over the past 25 years.
These incidents include the Sandoz incident in November of 1986 when a
chemical fire in an industrial warehouse near Basel in Switzerland laid
waste to the Rhine.1
Traditionally, discussion of the environmental impact of fires has
focused on the emissions that fires can cause both to the air, water and
soil; but in recent years a new debate has arisen where the impact of
chemicals on the environment and the precautionary principle have taken
While that debate began in the 70s, it still rages today.3
Most concerning is the polarization in the debate, where
environmentalist and fire safety specialists seem to be on either side
of the issue. Both groups are inherently interested in safety, but
without an accepted model to weigh environmental risks against fire
risks, the debate will continue to pit these risks against each other
qualitatively rather than quantitatively and resolution of the issue
will be difficult.
Fires produce a complex cocktail of effluents, all with varying modes
of action and longevity, toxicity and eco-toxicity. Typically, the
impact of fire emissions can be divided into acute and long term
In terms of the environmental impact of fire effluents, long term
effects are often more important than acute effects. Traditionally,
carbon monoxide (CO) is recognized as the main acute toxicant in fires,4 although numerous other gases can be as potentially important in determining the outcome of any given fire exposure.
Models for assessment of the effects of chemical compounds with an acute effect on people are available in ISO 13571.5 In contrast, large organic species, such as dioxins or polycyclic aromatic hydrocarbons (PAHs) are those species which are thought to have the greatest environmental impact.6
A guideline document for the assessment of the environmental impact from fires has been developed in ISO/TC92 SC3/WG6.7 This document presents emission pathways and species of interest from an eco-toxicological point of view. There are, however, no standards available for the quantification of the effect from fires on the environment.
The interaction between a fire and its surroundings (or environment)
is illustrated in Fig. 1. This figure shows that there are a number of
different emission pathways that allow a fire to impact the environment.
The effect of these emissions depends on the transfer mechanism (i.e.,
emission of gaseous species to the atmosphere, or emissions to the
terrestrial or aquatic environment), the susceptibility of the
recipient, and on the specific species.8
Assessing the Environmental Impact
Numerous environmental assessment methodologies exist ranging from
full life cycle analysis (LCA) tools to less detailed types of
environmental assessment tools. Traditionally, these tools assume an
incident-free life-cycle of the product or process being evaluated. This
means that in the case of a traditional tool, the function of a flame
retardant or an extinguishing medium in terms of a potential reduction
in the number and size of fires is not included.
In response to the limitations of traditional environmental assessment tools, the Fire-LCA model was first developed in 1995.9,10
The aim was to develop a tool that could be used for making a
quantitative comparison of the environmental impact of different fire
performance legislations. LCA was chosen as the basis for the
development as this is a widely used tool and sufficiently sophisticated
to include factors like the effect of the mitigation of fires.
It soon became apparent, however, that this model also has its
limitations, and the Fire-CBA model was developed to address some of
these limitations.11 These models represent the first
attempts to quantify the comparison of risks between fire emissions,
flame retardants and the potential impact of the environment.
The Fire-LCA model is best described in Figure 2. The Fire-CBA model
can be summarized in Table 1. A full application of the Fire-LCA model
can be found in reference 10 and of the Fire-CBA model in reference 11.
Table 1. Information requirements for Fire-CBA model.
Both the Fire-LCA and Fire-CBA models were developed in an effort to answer difficult questions concerning the relative merits of fire safety and the use of potentially undesirable chemicals. Both models provide a part of the answer but not the whole answer.
Further, as for all complex tools, the models are no better than
their input, and the quality of data across the whole life-cycle of a
product is generally patchy. There is a need to improve the assessment
stages of both models and to develop a global model, capable of taking
into account both emissions and their impact, and the societal impact of
different regulations and the cost-benefit of one choice against
Until such a model has been developed, it is not possible to answer
the question of whether the benefits of any individual flame retardant
(in terms of enhanced fire safety) outweigh the potential costs of that
chemical (in terms of environmental exposure). The development of such a
multi-parameter tool is a difficult, but important, task that will
require a significant amount of research in the future to realize. Even
without such a tool; however, it is not necessary to choose between fire
safety and environmental safety. Both must, and can, be protected
through the choice of relevant levels of fire safety and the judicious
use of chemicals that have been screened and approved by the type of
risk assessment commonly used in most developed parts of the world by,
e.g. the European Union or the US EPA.
Margaret Simonson McNamee is with SP Technical Research Institute of Sweden
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