Myth 1: Hazardous materials are always obvious

Many people think that a hazardous material is going to be obvious when they see it. They think of the glowing green liquids you see in movies or on TV shows, but in reality there are many materials that can be hazardous without having physical characteristics that would allow them to be identified as such.

Fact: Hazardous materials are not always obvious

NFPA 400, Hazardous Materials Code, classifies materials according to whether they are a health hazard or a physical hazard. Health hazardous materials may be toxic, highly toxic, or corrosive, while physically hazardous materials may be explosive, flammable, oxidizing, or unstable. Materials with these hazards may not have a distinguishing physical characteristic.

Since a hazardous material is not always obvious, it is important to provide visible hazard identification signs for both building occupants and first responders.

NFPA 704, Standard System for Material Hazard Identification for Emergency Response, can be used to create signs that identify health hazards, flammability, instability, and special hazards of materials. Below is a quick reference to the 704 identification system.

Myth 2: Wedging a door to keep it open is not dangerous

Many people may think that holding open a self-sealing door, as seen in the image below, is a harmless action.

However, if the door that is kept open is a fire door, this action endangers the lives of the occupants, as well as the integrity of the building, if a fire were to occur.

This is because a fire door is a mounting assembly that is installed in a fire wall or fire barrier to provide a degree of fire protection to that opening.

Fact: Wedging a door to keep it open is dangerous

If a fire door is unable to close automatically and latch, then it is unable to adequately protect the opening in the wall or fire barrier it is protecting. This will result in the fire being able to spread uncontrolled throughout the building and, more importantly, to areas such as hazardous locations or protected areas such as an exit stairway that occupants rely on to evacuate the building during a fire.

In other words, fire barriers and fire doors provide compartmentalisation within a building i.e. they are to limit the spread of fire from one area of a building to another. Looking at the same image, where you can see the two opposite sides of a fire door, it can prevent the fire from spreading to the next compartment. This would not be possible if the door were kept open.

Myth 3: Electric vehicles burn hotter than those with internal combustion engines

As the world begins to use more and more electric vehicles (EVs) for transportation, we have started to see fires related to

1. One of the myths we hear is that electric vehicles burn hotter than a typical internal combustion engine vehicle.

Fact: Electric vehicles do not burn hotter than those with internal combustion engines

Research from the Fire Protection Research Foundation, as well as a recent report published in the journal Fire Technology, conclude that, overall, electric vehicles do not pose a greater hazard than internal combustion engine (ICE) vehicles. ICE vehicles were found to have a higher peak heat release rate (HRR) due to the burning of fuel in the gas tank, but it burns quickly. EV fires tend to develop more slowly and not be as large, but they last much longer. Additionally,

Many of the other components of a vehicle, such as the plastic interior and body parts, are the same in an EV and an ICE vehicle, so those components will burn in a similar manner.

It's important to note that the lithium-ion (or similar) batteries that EVs are equipped with fail and burn in a very different way than the batteries in ICE vehicles. When lithium-ion batteries fail, they go through a process called thermal runaway, which is when the failure of a single cell can result in the production of heat and oxygen, as well as flammable and toxic gases. This process then trickles down to adjacent cells, leading to the potential for explosions or rapid fire spread. That, in addition to the other unique characteristics of an EV fire, such as stranded power and reignition, makes the firefighting response to an EV fire much more complicated than that of an ICE vehicle fire.

Myth 4: Smoke alarms in a hotel or apartment will trigger the alarm for the entire building

Many people think that all of the notification devices on the building's fire alarm system will activate if the smoke alarm in their apartment or hotel accidentally goes off, when in fact NFPA 101®, the Life Safety Code, would not allow that to happen.

Fact: Smoke alarms in a hotel or apartment will not trigger alarms in the entire building Section 9.6.2.10.11 of the 2021 edition of NFPA 101 requires that smoke alarms in dwelling units only sound within that individual dwelling unit and not within the entire building. This is because if an accidental activation of these alarms were to occur within one unit, the entire building would not need to be evacuated.

However, if a smoke detector in a common space of the building or a water flow alarm from the sprinkler system were to activate, the entire building would be notified to evacuate because the water flow from a sprinkler is less likely to be accidentally activated, and the spread of smoke into a hallway or common space would affect the occupants' ability to escape. In some cases, fire alarm systems are designed so that the smoke alarm within one of the units or rooms will send its signal to a constantly attended location, such as a security desk, so that someone can investigate.

Myth 5: Firefighters can easily see and communicate inside a burning building

It goes without saying that movies and TV shows don't necessarily accurately depict how something happens in real life, and this is certainly the case when it comes to depicting the conditions inside a structure fire. For example, sometimes TV shows and movies show that firefighters can easily see and communicate with each other when they're inside a burning structure, but that's not the reality.

Fact: Firefighters cannot easily see and communicate inside a burning building.

Fires inside a structure can reach temperatures of up to 1100° F (590° C) and create smoke that can significantly reduce or even eliminate any visibility inside the structure. Visibility is such a concern during fires that NASA is working on locating services for firefighters in case they themselves have an emergency and need to be rescued.

For this reason, NFPA 1001, Standard for Occupational Qualifications of Firefighters (consolidated in NFPA 1010), requires that firefighters be able to perform all indoor operations, such as search and rescue, under obscured vision conditions.

Summary

The field of fire protection and life safety is so broad and covers so many topics that it would be difficult for one person to understand it all. Just take a look at the 21st edition of the Fire Protection Handbook (FPH). To cover all the topics, it includes 210 chapters in two volumes written by more than 200 industry professionals and NFPA experts.

Prepared by: Shawn Mahoney, Technical Services Engineer, working on issues of

fire protection support in the NFPA.

Reference: Fire and Life Safety Myths (nfpa.org)

Source: https://www.nfpa.org