This particular week is part of a couple week discussion that we'll talk about fire safety systems. These fire safety systems that we talk about in this week will be a bit of an introduction. To it the fire safety systems principally that get installed in buildings though they could applied also in some ships and various transportation vehicles, offshore oil wells, and so on but we're going to talk principally about the buildings as our case study. The fire safety systems in particular that we will talk about in detail today will be detection and alarm systems, suppression systems with smoke control. There are other systems as you'll see as part of our introduction that get talked about in later weeks. So as we look to these fire safety systems that are provided. There are these set of seven fire safety systems altogether that are talked about and recognized in the fire protection and engineering field. Pretty much internationally I would have to say that there is agreement that these are the seven systems. So in no particular order, these are not prioritized or whatever by where they are in the circle, but you see these seven fire safety systems all have arrows pointing into fire safety objectives. So they're all there to accomplish, or help accomplish a set of fire safety objectives for the facility. The objectives of the fire safety systems are flammability of materials. So, it gets into material control type issues and what do we line the walls with? And what kind of furnishings are provided in the building. We look to protect the structure, provide egress and life safety systems basically, exiting systems. The fire department plays a role in some fashion, needs to be recognized and as such. There are smoke control systems, there are suppressions systems and detection alarm systems run away that their getting corporate in the building so I'll offer the reason of providing or accomplishing a particular set of fire safety objectives. So, what objectives come into play? Well, life safety is of course one of these and we want to protect people. Property protection and also protections of contents would be relevent. The property, sometimes people just think that to be the building, the structure itself, but we want to consider the building and it's contents. Protecting the mission is important. So, the facility may want to have relatively minor fire so, that they can re open in the next day, or the next month, or in some defined time period or they maybe some missions that they can't aboard, unless there are absolutely catastrophic circumstances going on and, you might imagine a hospital, being that mission protection is very important. Heritage preservation might be a significant objective in historic properties or in cultural resource properties, in museums and those sorts of places. And finally protecting the environment will be a part of some of the objectives stipulated for a facility as well. For example, let's look at life safety. In the NFPA 101, the National Fire Protection Association's codes and standards, NFPA 101, the life safety code, from the 2013 edition, the statement is made of an objective that of what that premise of the code is. And that is you can see, except for occupants intimate with ignition, no occupants shall be exposed to instantaneous or cumulative untenable conditions. So, aside from the people that are involved in starting the fire either as an act of negligence, maybe a criminal activity, or just an accident that they were part of. Aside from those individuals, everyone else, the life safety system is designed to make sure they get out. Property protection, another example. So this is a photo of one of the World Trade Center buildings, building five that was impacted by the events of 9/11. You can see that this building sustained complete burnout on that particular day, but it's still standing. There was a statement made in a research report from the building materials series from, at that point, the National Bureau of Standards, now that's NIST, the National Institute Standards and Technology, that made the following statement. It said, the idea of designing some buildings for the full fire severity corresponding to the arguments is a logical advance in fire protection engineering. So as made in the middle of the 20th century, the idea that you should get this outcome. They felt was a very reasonable approach and could be an objective. Fire protection engineers typically are interested in reducing the cost of fire. And it's not just in the losses, but what's the total amount of investment that's made in the name of fire safety. And it could include whatever fire protection cost, so the building protection cost. We have costs associated with fire departments, with providing fire insurance that whole array of costs and maintenance of systems. There are then losses that have occurred, direct losses, indirect losses, perhaps, that occur as a result of a fire. And the general idea is that we want to minimize the total costs. You could see that in the cost of fire protection or losses, one slide looking at the blue and the red curves that are here, in general with increasing protection and increasing investment in fire safety. One would hope that the cost of the losses come down. So there is that trend. You notice the losses never go to 0, all right, never go to 0 even with a huge expenditure, we're not going to go to 0. But we can get into it at least a minimum point that one might talk about as an objective. To the point that having fewer losses is not feasible. The other way of saying that is that complete safety is impossible to achieve. We cannot guarantee that for any incident that you might envision, that everyone gets out of the building. Despite the objective of NFPA 101, if there are explosions, if there are terrorist events. We may not be able to get everyone, we as fire protection engineers, may not be able to get everyone out of the building all the time. Every possible incident. So everything's got a design limit. It would be another way to say that. So the approach is typically to limit the risk associated with a fire to an acceptable level and that there are acceptable levels of risk that we talked about. Philosophically for how we live our normal lives. Whether we cross the street or not, there is a risk associated with that. Whether you engage in some sporting activity of skydiving or skiing, there are risks associated with that. And the are some of us like myself who see no reason to jump out of a perfectly fine airplane and do skydiving. So there are risk that we make personal decision about. Corporations similarly make those same sort of personal risk decisions. So what's risk though? I've talked a little bit about risk here, and before rambling on for a minute or two there, I probably should have come to this and then gone back to that. So what's this risk thing all about? Well risk is typically described as the loss, the probability of loss or injury to people, property, environment. I don't have all those words here, but would be the probability of harm basically to particular objectives we're trying to achieve. It generally expressed risk that is. It generally expressed as the product of a frequency the event and the magnitude or the consequence of that particular scenario. So we talk about acceptable risk usually using curves of this style or graphs of this style. Where we monitor or we plot up, rather, the frequency of events and the consequences of those particular scenarios that have a given frequency. And that anything down here is acceptable. Anything down here under the green line. The blue is simply to identify that for a particular scenario that has a given frequency, that scenario will have a particular expected loss outcome. So accepted risk is anything under the green and then basically the idea is that we accept things, even very low consequence events. That are some upper limit there, that if you're continually cutting your finger that there's a point at which, if doing some activity over and over again to the point that you're cutting your finger, it's a fairly minor thing, you're eventually going to stop that activity if you're getting a cut in your finger every minute. If it occurs once every half a year, well, that's life and we put up with that, paper cuts and and that sort right. As the consequences get more significant, our tolerance for those things goes down. So that there is some high consequence sort of event that we would have, we would not want to put up with as often. That's the whole point of acceptable risk curve, where unacceptable risk, anything up above the green curve. And again, philosophically at least, if not quantitatively in some cases that the fire protection design and what fire protection is included in buildings would be done to relate to whatever is the acceptable risk. So fire safety is provided in the buildings and what how much fire protection you see as you travel around different buildings you may not see sprinklers in every building. You'd say, why is that, and it gets back to some of the fundamentals of risk philosophy. So fire safety is provided to achieve a particular acceptable level of risk. Our safety systems are incorporated in the building designs to achieve selected fire safety objectives. So with that, we'll call this first segment to week two to an end and move into the segment two here very shortly where we'll talk about the fire safety systems.