ire protection is one of the most critical, yet inconspicuous, parts of building design that occupants need but hope they never have to use. This essential safety feature is more than alarms and sprinklers. Depending on the type of building, it can exist in ways people wouldn’t recognize. When it comes to fire protection, engineers take a holistic approach to designing a system that ensures the longevity of the structure and occupants inside.

Fire protection engineers begin the system design process with one vital question: how do we keep a fire from starting in the first place? This requires a thorough assessment of the project, what Nick Rodes, manager of engineering for NANA Worley, calls the “hierarchy of hazard controls.” This hierarchy is a systematic framework of five main components that all engineering disciplines use to increase safety. In the case of fire protection, these components—elimination, substitution, engineering controls, administrative controls, and personal protective equipment—guide the risk assessment before initial systems design.

At the top of this framework is elimination. Rodes says the simplest way to avoid a fire is to remove anything that can fuel one. Elimination includes constructing a facility away from other fire hazards, constructing the facility of fire-resistant materials, and removing highly flammable materials and solvents when possible. This is the main technique for fire safety management.

After eliminating hazards, fire protection engineers look at substitution. Some types of materials, machinery, and products with a medium-to-high fire safety risk will enter a facility. When fire protection engineers can’t completely remove a potential hazard, they consider ways to replace the hazard to minimize the risk.

The next step down on the hierarchy is engineering controls. At this level, engineers make physical changes to the workplace to increase fire safety, such as compartmentalizing the hazard or isolating people from risk. Administrative controls have less of an impact than the components above but still can increase safety. Here, engineers assess how people will work together and identify any process changes that can eliminate an existing hazard. The lowest level of control in this hierarchy, personal protective equipment, is less about prevention and more about minimizing damage by using fire-retardant materials, alarms, and fire suppressants.

“Only after we have figured out how to avoid a fire do we consider ways to alert occupants and stop a fire from spreading,” says Rodes.

Building codes also play a big part in risk assessment, according to Eliot Jordan, fire protection engineering discipline manager for Coffman Engineers. He points out that a hospital will have different fire protection needs than an office building or a North Slope oil and gas facility. Jordan says engineers consider the building occupancy type when they design aspects of a fire protection system. He stresses the importance of thinking of fire protection as more than little red pull boxes, pipes, and sprinklers. Fire protection is about life safety and implementing successful measures through looking at a bigger picture that includes construction, egress pathways, and other protective means.

“We determine what needs protection and then design components that will accomplish that goal,” says Jordan.

Perhaps the most spine-chilling sound one can hear is the blast of a fire alarm. However, Rodes says this is also a good thing because it means the alarm system is working. Alarms are just the start of the process of minimizing a fire once it’s started. Fire protection engineers use a mix of different suppression systems, fire-restraint barriers, extinguishers, and lighting to keep a fire at bay as people exit the building.

A larger fire suppression system is ideal for fires that can’t be managed with a portable extinguisher. Building-wide systems can release several suppressants, including water, gases, or foam. Rodes says the primary agent for many suppression systems is water; however, fire protection engineers may choose dry chemicals or some other agent in situations where water wouldn’t be appropriate, such as a grease fire, a location where oil or electrical equipment is present, or archival facilities with paper records.

Fire never changes, but techniques for putting out fires continue to evolve. Until the ‘90s, the best choice for building-wide fire suppression, especially where water and electronics would mix poorly, was Halon 1301, also known as bromotrifluoromethane. Widespread use was phased out by 2000 because of the Montreal Protocol, the international treaty to limit production of chemicals that deplete the ozone layer that protects the Earth from the Sun’s ultraviolet rays. These days, gaseous systems use alternatives like nitrogen, argon, or Novec 1230, an exotic chemical sometimes called “dry water” that 3M invented in 2004.

Rodes says the best time to start designing a fire protection system is at the very start of a project. This allows fire protection engineers to work with the design team to create a building layout that allows people to get out safely should a fire occur. He adds that pre-construction is also the optimal time to decide where to place alarms and suppression pipework and fixtures.

“It becomes a big challenge when design professionals leave fire protection until the end,” says Rodes. “I’ve been invited to projects where 90 percent of the design is already complete before considering fire protection. It becomes difficult to include these vital systems, if left ‘til last.”

Although fire prevention, detection, and suppression technology has advanced, Jordan says engineers still face the challenge of applying prescriptive solutions to a unique situation. Prescriptive designs use pre-defined rules and options to meet their goals. Though there is little variation in the methods and materials used in prescriptive designs, their applications are consistent—which is important when it comes to safety.

“Every facility is different,” says Jordan. “We direct the installation for that facility based on the conditions. From the smallest module to a big aircraft hangar, prescriptive solutions need to apply to the project at hand.”

All fire protection systems go through a testing process before the building is handed over to the owner. Since it isn’t feasible to spray water or chemicals on a newly constructed building, fire protection engineers have an alternative method to make sure the suppression system is functioning properly. Rodes says they conduct hydrostatic tests on the piping system by filling it with a liquid or gas and pressurizing it for a set amount of time. During that time, engineers look for any leaks that need to be repaired before the system is considered safe for use. Sprinklers are generally not tested on-site; however, they go through extensive laboratory testing and have a successful response record. Once these tests are complete, the fire protection system is ready to alert building occupants if a hazard occurs.

Regular maintenance ensures the system continues to function properly. In Alaska, commercial buildings must test their fire protection systems annually. Depending on the complexity of the system, this includes activating each detection advice, testing the alarm’s connection to the containment and suppression system, and, if applicable, checking that all backup power sources are functioning. Rodes says that building maintenance staff are allowed to do a limited amount of work on most systems, but a licensed professional should handle testing and most repairs.

“Frequently, people neglect to test smoke detection systems or disable them if they think they are going off for no reason,” says Rodes. “That is extremely dangerous. Don’t assume the system is wrong when it goes off. It might be telling you something about an unseen hazard that needs to be addressed, like a short circuit.”

Though the fire protection codes and standards set by the National Fire Protection Association haven’t changed much over the years, technologies have made prevention and protection systems more efficient. Fine mist suppression systems use a fraction of the volume of water compared to older systems, and Rodes says that engineers in Alaska have a much better understanding of incorporating preventative fire protection methods into buildings. Jordan adds that some past materials have proven problematic, which has driven the industry to innovate. Solutions such as firefighting foams and Halon systems resulted in a negative environmental impact, and he anticipates the industry will further evolve as engineers continue to find unique solutions to new situations.