Green and Safe Materials: Compatibility or Conflict? José L. Torero BRE Centre for Fire Safety Engineering The University of Edinburgh

Issues in Fire Safety Engineering o Integration of FSE to building design o Educational needs o Development of new tools o Structural modelling o Fire dynamics o Analysis of new technologies o Construction o Materials o Revisiting of existing knowledge

Integration o Fire Safety affects every aspect of a building Definition of Space Egress Structure Smoke management Building Services Alarm HVAC Water Security Access Monitoring Energy & Sustainability Insulation Building Fabric

Optimization o Currently fire safety is trying to integrate to other disciplines o Avoid unnecessary redundancy o Avoid unnecessary cost o Avoid unnecessary complexity o Avoid inefficiency

Evolution of Education o Educating professionals that understand the Fire Safety Strategy as part of the Built Environment o Provides answers before the questions are asked o Integrate/optimises systems o Allows the Architect: o Achieve what he/she wants o Circumvent problems o Avoid excessive engineering

How do Green Objectives Affect this? o Requires further optimization o Increases complexity o Limits options o Integration o Changes nothing!

Example: Green Materials o Natural Materials o No Fire Retardants o High thermal resistance/thermal mass o Low embedded energy o Recyclable, etc. o Changes nothing!

o Is there any incompatibility? o...just makes our job a bit more complicated o...just requires us to better engineers

Need to Understand o Small scale tests used to gather information about material o Tests defined implicit performance o Presence of retardants make unnecessary any further detail

Implicit Performance o Made understanding unnecessary o Retardants solved the problem o Standard test certified the problem was solved o The engineer did not have to think o We stopped thinking o Could not justify benefit of retardants o Environmental/Health cost became the single variable o We lost the war for fire retardants before it started

Further Demands o Lower thermal conductivity requirements are displacing non-flammable insulation o Energy conservation requirements are making flammable cavities ubiquitous o Reduction of embedded energy is requiring a reduction of protective layers, etc. o Changes nothing! o...If we had not forgotten how to think!

How do we take control? o We start thinking o Quantitative cost/benefit analysis o We need to scale up performance – benefit o We need provide effective protection – cost o We need to understand environmental impact - cost

Scaling up Performance- Stages o Ignition o Growth o Fire interacting with smoke o Flashover (secondary ignition) o Post flashover o Burnout

Complexity o Ignition o Simplest o No-combustion o No heat feedback from the flame o Complexity o Implies models of the gas and solid phase Water Losses Convection Radiation Heat Transfer Degradation Chemistry Heat Feedback (glowing) Mass Transfer Pilot - Gas Chemistry

We just have a more complicated problem... o Changes nothing! o Only if we are good enough engineers are we?

Could it be that my subject is neither man nor fish but a gawky representative of a new species? This species could have as its discipline the understanding and thence the bringing of a modicum of control to the hitherto intractable quality called "Safety", a word whose aura must surely extend beyond ourselves to our fellows, to those that follow us and even to mankind. And in the shadow of Safety there is always Risk which comes strongly into the light when the emphasis of our studies turns to the adventurous journey of mankind through time, space and such as might lie between. In pursuit of gaining the measure of Safety and Risk we could well find ourselves ranging unashamedly from Physics to History, why even beyond. For will we not be concerned with bringing what has been called "Acts of God", amongst which Fire has had such a terrible ranking, into the regime under man's control? What impudence, but if true it would be New Variation on an Old Theme indeed! Concluding paragraph of the Inaugural Lecture presented by Professor D. J. Rasbash on November 14 th, 1974 at Appleton Tower, The University of Edinburgh.