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Sep 6, 2021

Hello all! Welcome to episode 16 of Fire Code Tech. On this episode we are talking about how to determine the hazard for an occupancy. We take a look in this episode about the codes and standards around proper occupancy classification.  Don't forget to check out an additional episode about hazard determination on



Hello. Welcome to the solo cast of fire code tech in these episodes. It's just gonna be me, your host, Gus Gagliardi. There's gonna be a range of topics, but I'm gonna talk about specific technologies, installation, standards, codes, and how they work as well as some other interesting topics that don't neatly.

Inside of the context of a normal interview. Hello wall. Welcome to episode 16 of the solo cast of fire code tech. On this episode, we're talking about hazard determination. So one of the first steps and most important steps of designing a fire sprinkler system is determining the hazard. When I was learning how to design sprinkler systems.

In my first role in the industry, I found this to be one of the most difficult topics. There are a couple different things and, you know, just parts of being a professional that there aren't a lot of hacks for other than time and experience and reps and sets. And I think this is one of them. So I wanted to break into.

How I learned to, you know, determine hazard some tips and where places, where you can look to learn more about the subject and also just to explore the process of it and to dive into the codes and standards around hazard determination, and some of the different approaches there are. Applying a hazard to a, a building or a portion of a building.

Don't forget to subscribe and follow us on social media. So you never miss an episode. Also, if you could please, please, uh, smash the like button and give us a review on apple podcast. That would be such a big help. Let's get into the episode. So we talked a little bit about hazard determination in our episode.

Hydraulic calculations. And I started to get into quite a long stint about, uh, how to quantify a hazard. And I realized that this probably needs to be in an episode of its own. So here we go. Here's that episode. So the primary document for installing fire sprinkler systems in the United States is N F eight 13.

Which is gonna be the document that talks about how to quantify hazards. Some of the different characteristics of said hazards and, uh, some of the pertinent definitions for the process that we're talking about. There are other places where you can find information about hazard determination, like the building code and the fire code.

But I'd say first and foremost, we start with NFPA 13. So when I was learning about hazard determination, NFPA edition that I was using was the 2013 edition, which was what was adopted in Omaha at the time when I was starting to work. But, uh, the 2019 edition of the standard no longer has hazard determination in the same area, uh, as it was reorganized substantially in the 2019.

So in the 2013 edition, we're looking at chapter five classifications of occupancies and commodities. So in the 2019 edition of the standard, it's in chapter four where it describes, uh, light hazard, ordinary hazard one and two and extra hazard one and two. So let's go over the differences and similarities between the.

2013 and 2019, uh, classifications of hazard for occupancy. So you could say hazard determination or occupancy classification, or you can, there's a variety of terms, but basically we are trying to quantify the combustible loading or the amount of material in a space. That can catch on fire and sustain combustion and sort of, um, quantify that hazard, um, in broad terms so that we can apply, uh, densities.

So how much water per square foot is appropriate for how much combustibles? So in the 2013 edition, there's a little bit more of a wordy explan. So light hazard is described as light hazard occupancy shall be defined as occupancies, a portion of other occupancies where the quantity and or combustibility of contents is low and fires with relatively low rates of heats of release are expected.

If we take a look at the 2019 version of. This definition, it stated a little differently, and I would say more concisely. It says the following shall be protected with light hazard occupancy criteria and this standard. Then it says spaces with low quantity and combustibility of contents. So, uh, a lot more to read in between the lines with this second statement in N FPA 13, 20, 19 edition.

So in either case that's a very. Definition, you know, how do I, what, who defines what a, you know, light combustible loading or what a low heat, uh, release rate is. And so, uh, the standard doesn't explicitly state these things, but they do offer NX material to guide your interpretation of these, these guidelines.

So if you look at the information. In the annex corresponding to this portion or definition of light hazard occupancies, you can find, uh, you know, 16 examples of, uh, in the 2013 edition of light hazard occupancies. And so in time you will learn, um, through application of. Hazard determination and, you know, uh, reps and sets and looking at different buildings, uh, what spaces constitute, uh, low combustible loading.

And so, you know, examples given in the annex of light hazard are animal shelters, churches, clubs, Eves, and, uh, Eves and overhangs. Hospitals, including animal hospitals and veterinarian facilities, institutional facilities, kennels libraries, and several large stack rooms, museums, nursing, or convalescent homes, offices included data processing, residential restaurant seating areas, theaters, auditoriums, excluding stages in presidium and unused addicts.

So I probably didn't need to read all of those, but I wanted to give a good idea of. uh, what these light hazard occupancies look like. So when I think of light hazard occupancy, traditionally, I think of, uh, business occupancy, uh, low combustible loading, kind of sparse, uh, you know, desks or seating arrangements, um, nothing industrial or.

so storage, like moving on the next two categories are ordinary hazard one and ordinary hazard two. When looking in a ordinary hazard and extra hazard, ordinary hazard one and extra hazard, one are less hazardous than ordinary hazard, two and extra hazard. Two ordinary hazard group. One occupancies shall be defined as occupancies or portions of other occupa.

Where combustibility is low. Quantities of combustibles is moderate. Stockpiles of combustibles do not exceed eight feet and fires with moderate rates of heat release are expected. Ordinary hazard group one in the 2019 edition is stated as the following, the following shall be producted with oh one occupancy criteria in this standard.

Number one spaces with moderate quantity of and low combustibility of content. Stockpiles. Uh, this is the second, uh, option stockpiles of contents with low combustibility that do not exceed eight feet. So when I think of ordinary hazard, one group occupancies, I think of rims that might contain stores of materials.

Um, maybe more than you might expect general storage and business buildings, buildings, maybe, uh, janitors closet with, uh, stockpiles of extra materials. Um, just some rooms and buildings that are more hazardous, uh, occupied and sparsely loaded combustible. And so it's really just the next step up and is also, uh, very common in a low hazard occupancy.

Here are a couple of examples of ordinary hazard group, one, occupancies, automobile parking and showrooms, bakeries, beverage manufacturing, canneries, dairy products, manufacturing, and processing electronics, plants, glass, and. Products manufacturing, laundries, restaurant service areas, pork caches, and mechanical rooms.

So what you can tell about most of these different examples of group one group, one ordinary hazard, one occupancies is that there are, uh, combustibles more than average in just a general sense, but they're fairly non combustible. And there is just a moderate amount of 'em notice that there is a storage height threshold of less than eight feet.

This is important. Remember that when we get in excess of 12 feet, we are in high powered storage, uh, classification by the building code. Moving on to ordinary hazard group two ordinary hazard group two is described as the following. The following shall be protected with oh two occupancy criteria for this standard spaces.

With moderate high, moderate to high quantity of spaces with moderate to high quantity and combustibility of contents. And the second part of this description is stockpiles of contents with moderate to high combust combustibility that do not exceed 12 feet. There are quite a lot of different examples of ordinary hazard group two, but let's rip off the first 10 agricultural facilities, Barnes and stable cereal mills, chemical plants, ordinary confectionary products, distilleries, dry cleaners, exterior loading.

Do docks. Note that exterior loading docks only use for loading and unloading of ordinary combustible Chevy classified as oh two for the handling of flammable and combustible liquids, hazardous materials, or were utilized for storage, exterior loading docks, and all interior loading docks should be protected based on the act actual occupancy and the materials handled on the dock.

If the materials were actually stored in that configuration, while I almost made it all the way through that without messing up. But. I guess you have to live through one mess up. And then the last two are feed mills and horse stables. So there are a couple more, uh, examples about 20 more actually. And so what you can think about ordinary hazard too, is we really start to get into some pretty situations, uh, some different manufacturing and, um, uh, high storage areas.

And we're really starting to get close to, um, uh, miscellaneous storage of fairly dangerous things. And so I don't have a lot of great, um, examples. I'd say a really good one is repair garages. I think that pretty much perfectly embodies what I think of at ordinary hazard group two occupancy. And yeah, so think of it.

It's, uh, definitely more dangerous. Could potentially have some, uh, flammables and combustibles, but obviously that has to be limited. So, yeah. So I think I'm going to end it at ordinary has a group two and in the solo cast bonus episode on the Patri. We will finish up extra hazard and break into classification of commodities, maybe.

So thank you all for listening and we'll see you next time on fire code. Thanks for listening. Everybody. Be sure to share the episode with a friend, if you enjoyed it, don't forget that fire protection and life safety is serious business. The views and opinions expressed on this podcast are by no means a professional consultation or a codes and standards interpretation.

Be sure to contact a licensed professional. If you are getting involved with fire protection and or life safety. Thanks again. And we'll see you next time.