By Jeff Moran
The impact of utilities on emergency situations for the fire service has changed in recent years. The utilities themselves have remained relatively constant, consisting of electric power, fuel (natural or petroleum gas), water (hot and cold), communications, and waste removal/drains. However, the conduit delivering them has changed in the construction material and the quantity present. These changes must be considered and integrated into the size-up, strategic decisions, and tactical executions to meet the challenges of a fire or rescue situation in new or renovated construction.
The study of structural firefighting must have its base anchored in a thorough knowledge of the battlefield, building construction. The knowledge must encompass construction materials and methods from the period of your oldest structures to those not yet completed. This is a dynamic field that requires a dynamic mindset. As Mark Twain reminds us, “It ain’t what you don’t know that gets you into trouble. It’s what you know for sure that just ain’t so.”
This article focuses on an area of the building construction field and its potential impact on firefighting operations. Our operational world is changing, and our knowledge must be updated frequently to operate effectively. This article is not a debate on the pros and cons of the changes in utilities. The utility equipment, materials, and installation methods are safe for their intended use when they are in compliance with the applicable codes as adopted by the authority having jurisdiction. The article is intended to increase awareness of the changes and the potential effects they may have on the fire service.
Water Delivery and Waste Water Removal
New installations are being made with plastic piping. Hot and cold domestic potable water piping is predominately made of a high-density polyethylene referred to as “HDPE” or “PEX.” It is a flexible tube which eases installation and minimizes joints for turns/curves throughout the length of the pipe. The piping is white for domestic water or blue for cold domestic water and red for hot domestic water. It is common practice to run a hot/cold pair from the water distribution point directly to the intended outlet point rather than using a tee fitting for each outlet from a single supply line, as is the practice with copper pipe. Hydronic heating may also be piped with PEX, which is orange in color. (photos 1-2). Polyvinyl chloride, or PVC, is another material used to manufacture pipe and is commonly referred to as white plastic pipe (photo 3). It is used for both water supply and waste/drainage pipes. Acrylonitrile butadiene styrene, or ABS, is another plastic material used to manufacture pipe and is commonly referred to as “black plastic pipe.” It is used for waste and drainage pipes that are not pressurized. These pipes are run through walls and above ceilings. The individual pipes may offer advantages from the construction and maintenance perspective, but they add to the plastics fire load and drop down entanglement hazard and contamination/exposure risk from the fire service perspective.
(1) Hydronic heating pipes (orange) made of high-density polyethylene (PEX). Red denotes hot water, domestic; blue denotes cold water, domestic; and white denotes hot or cold water, domestic. (Photos by author.)
(2) The PEX tubing installed.
(3) PEX tube and PVC pipe installed in 50-year-old home.
Photos by author.
The referenced pipe materials are all thermoplastics and, by the nature of their chemical composition, will begin to lose strength and decompose as they are exposed to heat. This will start as temperatures begin to exceed approximately 550˚F. The plastics will not continue to burn independently; they will burn when the combustion is supported by flame impingement from surrounding materials.[1]
The fire service must remain cognizant of the potential for these pipes to fail and release their contents. The contents may be domestic and/or waste water or chemicals, in an industrial facility.
Plastic pipes will release various contaminates as they decompose in a fire. Some identified by products of their combustion are carbon monoxide, volatile organic compounds (VOCs), aldehydes, benzene, hydrogen cyanide and dioxins.[2] [3] [4] [5] [6]The effects of exposure to these by-products of plastic combustion are apparent when looking at the New York Telephone fire of 1975 and the Beverly Hills Super Club fire of 1977. The incidence of respiratory ailments and cancers in the exposed populations of these fires exceeds that of the general population.[7] It must also be noted that none of these people were using positive-pressure self-contained breathing apparatus (SCBA), which is universal in today’s U. S. fire service. The use of SCBA during the firefight and overhaul will greatly aid in mitigating this hazard.
The plastic pipes may possibly burn or melt to the point where they could collapse in or completely fall out of the pass through penetration in a floor or wall, opening an avenue for fire spread. This possibility must be factored into the equation when checking for extension.
change in the piping used for gas distribution in a residential structure has also occurred in recent years. A flexible corrugated stainless steel tube, referred to as “CSST,” may be installed in place of black iron (steel) pipe (photos 4-5). This is not the same as a gas appliance connector.
(4) A flexible corrugated stainless steel tube (CSST) gas tube. Note its almost smooth appearance.
(5) A CSST gas tube installed in 50-year-old home.
(6) A gas appliance connector tube. Note its pronounced ridges as compared to the CSST tube.
The CSST has a yellow polyethylene jacket and is nearly smooth on the outside, whereas an appliance gas connector has a coating and pronounced ridges[8] (photo 6). The advantages of CSST are similar to those of PEX tubing for water. It is flexible, thus requiring fewer fittings, which translates into fewer potential leak points. CSST has a wall thickness of 1/15 that of black iron pipe, or 0.008 inch vs. 0.12 inch. A strong electrical arc may cause a hole in the CSST as the electric seeks ground, whereas the thicker steel pipe may withstand the damage.[9] Members conducting overhaul must be aware of the presence of CSST when pulling walls and ceilings. It has a different feel than black pipe. A member may pull harder when feeling the non-ridged resistance of the CSST, especially when pulling a plaster on metal lath wall or ceiling. This could cause a leak and release gas, which can ignite; even with the gas supply shut down, there may be residual gas in the lines. CSST may also drop down from its ceiling mounting, much like wiring or tubing, if the mounting brackets or joists are damaged or fail.
Communication Devices
The exponential growth of communication devices and the accompanying cables also contributes to the plastics load found in and on structures. The cables are coated with plastic, generally PVC. It will behave in the same manner as the PVC pipe. The plastic smoke exposures in the New York Telephone fire of 1975 were from the burning cable coating.[10] [11]Communication cables are run vertically and horizontally throughout all types of occupancies. Horizontal cables may be above ceilings or below floors, especially in computer areas of commercial occupancies. This presents entanglement hazards and fire spread avenues in addition to the exposure to plastics smoke.
The growth of communication devices has created another area in which the fire service is impacted. The need for antennas by communications companies and the potential for income from building owners has led to the installation of these antennas on many of the taller buildings throughout the country. You must be aware of the potential presence of the devices and the potential hazards they present. The antennas are frequently installed along the roof edge or on the parapet and can obstruct or complicate roof access/egress, particularly from/to ladders (photos 7-8). The antenna mounts may fail during a fire from high winds or being struck by master streams and turn the antenna into a flying hazard (photo 9). They also add an eccentric load to the wall on which they are mounted. This load is increased with ice buildup from winter storms and firefighting operations.
(7) Roof-mounted antennas
(8) This wall-to-screen antenna and equipment obstruct access to the roof.
(9) A ridge-straddling roof bracket for the satellite dish is held by weight of blocks and gravity.
These antenna must be treated much as we treat signs hung on wall-mounted brackets. The antenna will also have cable from it to a communications shed or into the building. This adds a tripping hazard to the roof. Some small satellite dish installations, especially on small commercial buildings like gasoline stations or convenience stores, may be mounted simply with a bracket straddling the ridge pole and weighted down with concrete blocks. There may be no fixed anchoring system. They are particularly susceptible to becoming projectiles in high winds or when struck by a master stream. All of these components also add a load to the building. Most of the buildings were built long before such equipment was invented, so this additional load was not likely calculated in the structural design. This may hasten the structure’s becoming compromised. Note also that communication equipment is energized. It may have both A/C and D/C current; most ‘voltage detectors’ we use are for A/C only. Like electrical equipment, the communication equipment shall be considered “live” until it is confirmed to have been deenergized.
Electrical Power
Another area of utilities that has changed in recent years is electrical power. A variety of renewable, or “green,” electrical power sources have been developed. They are becoming commonplace as their initial cost decreases and government regulations promote such power sources. The most common renewable power generation sources found on and around buildings are solar panels and wind-powered turbines.
Solar Panels
Solar panels may be installed on roofs; some may appear much like roof shingles, on the ground (solar fields), or attached to utility poles. Any light reaching the panels will be converted into D/C electrical power, which is conducted from the panels to an inverter where it is converted into A/C power and is either consumed on site or enters the power grid. Remember that our common power detection devices are for A/C electrical current only. The A/C portion of the electrical circuits may be isolated by disconnecting both the grid power feed and the D/C-to-A/C inverter transfer, but the solar panels and the conductor to the inverter will remain energized as long as there is light available to the panels. Be aware of the locations of these panels, and take care not to contact them or the D/C conductor-to-the-power inverter. Even after power from the public grid has been disconnected, they will remain energized. Note the presence and locations of this equipment in preplans, and also clearly mark them on the equipment and the door to the room containing this equipment.
(10) Solar panels on a 45-year-old lightweight wood truss roof. They add a dead load and obstruct roof access. Beware of falling snow/ice in large, heavy quantities.
Solar panels also add a load to the roof on which they are installed. They add two to four pounds per square foot of panel.[12] Snow and ice may build up and become trapped under the panels, adding more weight. Strong winds can blow under the panels, stressing the roof structure. The roofs on most buildings built before 1970 were constructed with no consideration of solar panels. The added loads imposed on the roof structures must be a size-up factor, especially when operating at a building with older lightweight roof trusses.[13] (photo 10). We who work in areas with snowfall must be aware of large volumes of snow sliding off solar panels. This can be heavy and readily injury anyone below. If you have to operate on a roof with solar panels, exercise caution for the added tripping hazards presented by the mounting brackets and electrical conductors in addition to the electrical hazards noted above.
Utility poles are also mounting locations for solar panels, usually a single panel per pole. They will energize the attached power equipment, including street lights and power conductors. I experienced this firsthand a couple of years ago when dispatched to a report of a motor vehicle accident with wires and pole down just as our shift was beginning. The response consisted of one engine and one truck and me in the car. On arrival with the police units, we discovered that the accident had been handled a few hours earlier during the previous shift.
The location in our report was the same avenue but a different cross street. A pole and wires were down; they had been removed from the road and the power conductors had been physically cut by the electric utility. I decided to use the opportunity to have a probationary firefighter gain some experience using the A/C power detection equipment. While doing so, he reported that the conductors on the ground were energized. The downed pole was one of three on a dead-end power line used exclusively for street lights, and the power supply had been cut to the power grid. The poles all had single unit solar panels with self-contained invertors which, once the sun rose, were doing their job and generated power and thus energized the conductors and street lights (photo 11). This reinforces the concept that power equipment is to be considered energized until confirmed deenergized. The utility must disconnect both the grid power source and all pole-mounted solar panels to render the conductors safe.
(11) The utility pole-mounted solar panel with DC/AC inverter connected to the local power grid.
(12) Wind turbines (vertical) on the roof of a six-story multiple dwelling. They may appear to be a solid cylinder when operating/spinning.
Wind Turbines
The wind turbine is another type of renewable or “green electric power-generating equipment. I am referring to roof-mounted units, usually with vertical vanes to capture the wind. These units generate D/C power, transmitting and converting it to A/C power in a manner similar to solar panels. There will be inverter and disconnect equipment within or adjacent to the building. Note the location of this equipment in preplans, and label clearly the equipment and the door securing the room in which it is contained. The turbines on the roof, especially several stories up, may appear to be a communications antenna. Turbines present all the same hazards and obstacles as an antenna plus the additional hazards of high-voltage D/C power and spinning turbine blades (photo 12). An additional factor to consider is the effect the vibration of the spinning turbines has on the mounts and the roof structure and whether the roof was designed to withstand this as it is impacted by a fire or the aging process.[14] The equipment may be safe and secure when installed; time has a way of taking a toll on it, as it does on all building components.
Generators and Other Power Supplies
Consider backup or emergency generators and uninterrupted power supplies (UPS) when engaging in utility control. I have encountered them in buildings ranging from private single-family dwellings to residential and commercial high-rises to a 300-store covered mall. Fixed location emergency generators are usually on the exterior, but they may be roof mounted, possibly in a roof-top shed. Preplans will reveal the presence, location, fuel type, and shutdown and disconnect locations. Fixed location generators are most commonly fueled by natural or liquefied petroleum gas (LPG) or diesel fuel. They normally supply A/C power to the building power circuits through a transfer switch. All or selected circuits may be supplied, so all must be considered energized. You can use the generator disconnects or the electrical panel to control the power by shutting down the panel main or individual breakers. The power disconnect at or adjacent to the electric meter will disconnect only the grid power source and will activate the emergency generator, as it senses this as a power interruption during which it is designed to supply power.
You may also encounter small gasoline, diesel, or compressed gas and natural or LPG generators. They are most commonly found at small commercial or small residential buildings. They are also prevalent at construction sites. Their power is normally conducted directly from the generator to the end use point by extension cords. The extension cords may be run throughout the building, presenting a trip hazard and potential electrical shock hazards because of cord damage; overloading; and connections submerged in water, snow, or ice. These generators should be on the exterior, but they are found in buildings where they create a carbon monoxide-laden atmosphere. Both the asphyxiant and explosive nature of this hazard is a critical tactical consideration.
Monitoring of the building atmosphere is imperative to enhance the safety of members and civilians when operating at scenes with portable generators in or immediately adjacent to them. The presence of these generators is usually detected during a 360 size-up survey. They also are somewhat noisy and can be shut down at the generator engine, similar to the small engine on lawn equipment. A building having power during a power outage is a strong indicator of the presence of an alternate power source; determine what it is and how to control it safely.
UPS may range from a small unit the size of a shoe box for a home or office computer to a bank of batteries occupying a large area. I had a high-rise with a public safety communications facility in it that had an uninterrupted power supply wet cell battery bank filling a 125-foot by 125-foot area on the 10th floor. Note the large UPS location and disconnect in preplans. The small commercial and residential units are normally located with the equipment they supply and are limited in their output. There are intermediate units that are approximately the size of a two-drawer file cabinet. Thy usually supply a small number of units (computers, electronic door locks, openers, communications equipment). Preplans and building occupants can help you to locate these units and control them as necessary.
Environmental and finite fossil fuel supplies have led to the development and proliferation of renewable source or “green” power generation. The dependence on electrical-powered technology has developed a demand for an electrical power supply that must be augmented during grid power outages. Material and labor costs in conjunction with material weight have altered much of the commonly seen building materials, especially in the plumbing trade. The fire service must be aware of these changes and adapt preplanning activities, strategy, and tactics accordingly. As the world evolves, so must we.
Endnotes
[1] Huggett, Clayton and Levin, Barbara C. Toxicity of the Pyrolysis and Combustion Products of Poly (Vinyl Chlorides): A Literature Assessment; U.S. Dept. of Commerce, National Bureau of Standards, National Engineering Laboratory, Center for Fire Research. Gaithersburg, Md. 20899. U.S.A.
2 Huggett, Clayton and Levin, Barbara C.
3 Fire.NIST.Gov/bfmlpubs/Fire87/PDF/f87015.pdf
4 Fire.NIST.Gov/bfmlpubs/Fire86/PDF/f86017.pdf
5 Fire.NIST.Gov/bfmlpubs/Fire87/PDF/f87017.pdf
6 Saskatchewan Ministry of Environment; EPB-433 Health and Environmental Effects of Burning Waste Plastics.
7 Wallace, D. “Dangers of Polyvinyl Chloride Decomposition. Long-term Health Impairments. Studies of Firefighters of the 1975 New York Telephone Co. Fire and Survivors of the 1977 Beverly Hills Supper Club Fire.
8 http://www.Structuraltech1.Com/2010/04/csst.
9 Carmoney, Mike; Concerns About CSST Gas Lines – “Grounded in Reality?”
10 Wallace, D.
[1]1 Port, Bob, New York Daily News, March 14, 2004; “Three Decades After an Infamous New York Telephone Company Blaze, Cancer Ravages Heroes.”
[1]2 www.Structural101.Com/Solar-Panels-On-Sloped-Roof-html.
[1]3 www>Structural101.Com/Solar-Panels-On-Sloped-Roof.html.
[1]4 Moorehouse, Andy; “Structure Borne Sound and Vibration from Building Mounted Wind Turbines.” IOP Publishing, Ltd,. 30-August-2011.
BIO
Jeff Moran retired captain/shift commander from the Woodbridge (NJ) Fire Department, where he served for 1-plus years also as a firefighter, fire inspector, and fire investigator. He was an occupational safety professional and industrial fire protection professional in large manufacturing facilities, including oil and precious metals refineries, for seven years and as an occupational safety consultant, compliance officer for the New Jersey Department of Labor for five years. He has a master’s degree in administrative science from the Fairleigh-Dickinson University Public Administration Institute and undergraduate degrees in fire science technology, industrial safety and political science. He is a NJ Level II fire and fire drill ground instructor, EMT, American Heart Association CPR instructor, a certified SCUBA diver, and a rescue IAFF fireground survival program instructor. He is a member of the International Association of Firefighters, Professional Firefighters of New Jersey, American Society of Safety Engineers, and the International Society of Fire Service Instructors
_________________________________________________________________________________________________________________
[1] Huggett, Clayton and Levin, Barbara C. Toxicity of the Pyrolysis and Combustion Products of Poly (Vinyl Chlorides): A Literature Assessment; U.S. Dept. of Commerce, National Bureau of Standards, National Engineering Laboratory, Center for Fire Research. Gaithersburg, Md. 20899. U.S.A.
[2] Huggett, Clayton and Levin, Barbara C.
[3] Fire.NIST.Gov/bfmlpubs/Fire87/PDF/f87015.pdf
[4] Fire.NIST.Gov/bfmlpubs/Fire86/PDF/f86017.pdf
[5] Fire.NIST.Gov/bfmlpubs/Fire87/PDF/f87017.pdf
[6] Saskatchewan Ministry of Environment; EPB-433 Health and Environmental Effects of Burning Waste Plastics
[7] Wallace, D. Dangers of Polyvinyl Chloride Decomposition. Long term Health Impairments. Studies of Firefighters of the 1975 New York Telephone Co. Fire and Survivors of the 1977 Beverly Hills Supper Club Fire
[8] HTTP://WWW.Structuraltech1.Com/2010/04/csst
[9] Carmoney, Mike; Concerns About CSST Gas Lines – “Grounded in Reality?”
[11] Port, Bob, New York Daily News, March 14, 2004; Three Decades After an Infamous New York Telephone Company Blaze, Cancer Ravages Heroes.
[12] WWW.Structural101.Com/Solar-Panels-On-Sloped-Roof-html
[13] WWW>Structural101.Com/Solar-Panels-On-Sloped-Roof.html
[14] Moorehouse, Andy; Structure Borne Sound and Vibration from Building Mounted Wind Turbines; IOP Publishing, Ltd. 30-August-2011
BIO
Biographical sketch:
Education: Masters of Administrative Science, Fairleigh-Dickinson University Public Administration Institute
Undergraduate degrees – Fire Science Technology, Industrial Safety and Political
Science
Professional: Retired Captain/Shift Commander, 19 + yrs., firefighter, fire inspector, investigator 6 yrs. – Woodbridge NJ Fire Department.
7 yrs. as an Occupational Safety Professional and Industrial Fire Protection Professional in large manufacturing facilities, including oil and precious metals refineries.
5 yrs. Occupational Safety Consultant, Compliance Officer – NJ Department of Labor
New Jersey Level II Fire and Fire Drill Ground Instructor
New Jersey EMT
American Heart Association CPR Instructor
Certified SCUBA diver, rescue
I.A.F.F. Fire Ground Survival Program Instructor
Member: International Association of Firefighters
Professional Firefighters of New Jersey
American Society of Safety Engineers
International Society of Fire Service Instructors
