Fire Risk Sub-Model

Comprehensive Fire Safety Effectiveness Model

Fire Risk Sub-Model

(Fire Risk Sub-Model PDF version available on request at AskOFM)

Table of Contents

1.0 Introduction

2.0 Risk

2.1 Definition

2.2 Probability Levels

2.3 Consequence Levels

2.4 Overall Level of Risk and Priority

3.0 Community Fire Risk Factors

3.1 Property Stock

3.2 Building Height and Area

3.3 Building Age and Construction

3.4 Building Exposures

3.5 Demographics Profile

3.6 Geography/Topography/Road Infrastructure

3.7 Past Fire Loss Statistics

3.8 Fuel Load

4.0 Assessing Fire Risk Scenarios

5.0 Summary

Appendix A: References

1. Introduction

Assessing the fire risk within a community is one of the seven components that comprise the Comprehensive Fire Safety Effectiveness Model. It is the process of examining and analyzing the relevant factors that characterize the community and applying this information to identify potential fire risk scenarios that may be encountered. The assessment includes an analysis of the likelihood of these scenarios occurring and their subsequent consequences. In essence, fire risk assessment attempts to answer the following questions.

  1. What could happen?
  2. When could this happen?
  3. Where could this happen?
  4. Who could this happen to?
  5. Why could this happen?
  6. How likely is it to happen?
  7. How bad would it be if it did happen?

This information serves as the basis for formulating and prioritizing fire risk management decisions to reduce the likelihood of these events from occurring and to mitigate the impact of these events when they occur.

2.0 Risk

2.1 Definition

Risk is defined as a measure of the probability and consequence of an adverse effect to health, property, organization, environment, or community as a result of an event, activity or operation. For the purposes of the Fire Risk Sub-model, such an event refers to a fire incident along with the effects of heat, smoke and toxicity threats generated from the incident.

2.2 Probability Levels

The probability or likelihood of a fire within a community is often estimated based on the frequency of previous experiences. A review of past events may involve extracting relevant historical fire loss data, learning from the experiences of other municipalities, and consulting members of the community with extensive historical knowledge. Professional judgment based on experience should also be exercised in combination with historical information to estimate probability levels. An evaluation of the probability of an event can be categorized into 5 levels of likelihood:

Table 1: Likelihood Levels

Description

Level

Specifics

Rare

1

-may occur in exceptional circumstances
-no incidents in the past 15 years

Unlikely

2

-could occur at some time, especially if circumstances change
-5 to 15 years since last incident

Possible

3

-might occur under current circumstances
-1 incident in the past 5 years

Likely

4

-will probably occur at some time under current circumstances
-multiple or recurring incidents in the past 5 years

Almost Certain

5

-expected to occur in most circumstances unless circumstances change
-multiple or recurring incidents in the past year

Note: The frequency of incidents provided should only be used as a general guide when determining this value. It should be complemented with consideration of events that occur within other communities. Events that have not taken place for a long time in your community may occur more frequently elsewhere. This may serve as an indicator that there could be a strong likelihood than what historical data indicates.

2.3 Consequence Levels

The consequences as a result of fire are the potential losses or negative outcomes associated with the event. The application of professional judgment and reviews of past occurrences are important methods used for quantifying consequence levels. Estimating the consequence level due to fire involves an evaluation of four components:

  1. Life Safety

Injuries or loss of life due to occupant and firefighter exposure to life threatening fire or other situations

  1. Property Loss

Monetary losses relating to private and public buildings, property content, irreplaceable assets, significant historic/symbolic landmarks and critical infrastructure due to fire

  1. Economic Impact

Monetary losses associated with property income, business closures, downturn in tourism, tax assessment value, employment layoffs due to fire

  1. Environmental Impact

Harm to human and non-human (i.e. wildlife, fish and vegetation) species of life and general decline in quality of life within the community due to air/water/soil contamination as a result of fire and fire suppression activities

An evaluation of the consequence due to fire can be categorized into 5 levels based on severity:

Table 2: Consequence Levels

Description

Level

Specifics

Insignificant

1

-no life safety issue
-limited valued or no property loss
-no impact to local economy and/or
-no effect on general living conditions.

Minor

2

-potential risk to life safety of occupants
-minor property loss
-minimal disruption to business activity and/or
-minimal impact on general living conditions.

Moderate

3

-threat to life safety of occupants
-moderate property loss
-poses threat to small local businesses and/or
-could pose threat to quality of the environment.

Major

4

-potential for a large loss of life
-would result in significant property damage
-significant threat to large businesses, local economy and tourism and/or
-impact to the environment would result in a short term, partial evacuation of local residents and businesses.

Catastrophic

5

-significant loss of life
-multiple property damage to significant portion of the municipality
-long term disruption of businesses, local employment, and tourism and/or
-environmental damage that would result in long-term evacuation of local residents and businesses.

2.4 Overall Level of Risk and Priority

The overall risk assessment is completed by assigning probability and consequence levels to potential adverse events or scenarios due to fire and combining the two to arrive at an overall risk level. The Risk Analysis Matrix is an analytical tool that can be used for this purpose. The highest overall risk levels are located in the bottom right corner of the matrix and the lowest levels are at the top left corner. This tool also allows the analyst to rank and classify the scenarios for the purpose of prioritizing risk reduction measures.

Table 3: Risk Analysis Matrix

RISK ANALYSIS MATRIX-Level of Risk (Priority Level)

Probability

Consequence

1

(Insignificant)

2

(Minor)

3

(Moderate)

4

(Major)

5

(Catastrophic)

1

(Rare)

L (L1)

L (L1)

M (L2)

H (L3)

H (L3)

2

(Unlikely)

L (L1)

L (L1)

M (L2)

H (L3)

E (L4)

3

(Moderate)

L (L1)

M (L2)

H (L3)

E (L4)

E (L4)

4

(Likely)

M (L2)

H (L3)

H (L3)

E (L4)

E (L4)

5

(Almost Certain)

H (L3)

H (L3)

E (L4)

E (L4)

E (L4)

The risk and priority levels are defined as follows:

  • L = Low Risk

Priority Level 1 (L1)-manage by routine programs and procedures, maintain risk monitoring

  • M = Moderate Risk

Priority Level 2 (L2)-requires specific allocation of management responsibility including monitoring and response procedures

  • H = High Risk

Priority Level 3 (L3)-community threat, senior management attention needed

  • E = Extreme Risk

Priority Level 4 (L4)-serious threat, detailed research and management planning required at senior levels

3.0 Community Fire Risk Factors

The types of fire risks that a community may be expected to encounter are influenced by its defining characteristics. For example, a “bedroom community” presents a different set of circumstances over one that is characterized as an “industrial town”. Communities that are distinguished by older buildings will pose a different set of concerns over those that are comprised of newer buildings constructed to modern building codes. Communities populated by a high percentage of senior citizens present a different challenge over ones with a younger population base.

Assessing fire risk should begin with a review of all available and relevant information that defines and characterizes your community. Eight key factors have been identified that contribute to the community’s inherent characteristics and circumstances. These factors influence events that shape potential fire scenarios along with the severity of their outcomes:

  1. Property Stock
  2. Building Height and Area
  3. Building Age and Construction
  4. Building Exposures
  5. Demographic Profile
  6. Geography/Topography/Road Infrastructure
  7. Past Fire Loss Statistics
  8. Fuel Load

The review should consider the factors independently as well as in combination with each other to identify potential fire related concerns within the community.

3.1 Property Stock

It is important to develop a community property stock profile to establish a detailed inventory of potential property related risks. This involves determining building stock totals based on occupancy classification as well as other non-building properties that could pose a risk to the community. The Ontario Building Code (OBC) categorizes buildings under the following major occupancy classifications, each of which has inherent hazards that distinguish it from the others.

3.1.1 Assembly Occupancies

An assembly occupancy is defined as one that is used by a gathering of persons for civic, political, travel, religious, social, educational, recreational or like purposes or for the consumption of food or drink.

Assembly buildings are often occupied by a large number of people and may contain high quantities of combustible furnishings and decorations. Occupants are generally unfamiliar with the building’s exit locations and may not know how to react in the event of an emergency. Low light conditions are inherent to some of these occupancies and can contribute to occupant confusion during an evacuation. Numerous examples exist of disastrous events that have occurred throughout the world, resulting in multiple fire fatalities in these occupancies. Therefore, these facilities warrant special attention. Accordingly, it is paramount to ensure that maximum occupant load limits are not exceeded, detection is available, an approved fire safety plan is in place and adequate unobstructed exits/means of egress are readily available.

3.1.2 Care or Detention Occupancies

A care or detention occupancy means the occupancy or use of a building or part thereof by persons who

  1. are dependent on others to release security devices to permit egress,
  2. receive special care and treatment, or
  3. receive supervisory care.

In addition to the presence of vulnerable occupants, these occupancies may contain quantities of various flammable/combustible liquids and gases, oxidizers and combustible furnishings that will impact the intensity of the fire if one should occur. The evacuation or relocation of patients, residents or inmates to an area of refuge during an emergency poses additional challenges in these facilities. It is essential to ensure that properly trained staff is available and prepared to quickly respond according to the facility’s approved fire safety plan.

3.1.3 Residential Occupancies

A residential occupancy is defined as one that is used by persons for whom sleeping accommodation is provided but who are not harboured or detained to receive medical care or treatment or are not involuntarily detained.

In Ontario, residential occupancies account for 70% of all structural fires and 90% of all fire deaths. Residential units that are located in multi-unit buildings, including secondary units in a house, pose additional risks due to egress and firefighting accessibility challenges.

3.1.4 Business and Personal Services Occupancies

A business and personal services occupancy is defined as one that is used for the transaction of business or the rendering or receiving of professional or personal services.

Many office buildings are occupied by a large number of people during business hours and contain high combustible content in the form of furnishings, paper, books, computers and other office equipment/supplies. Those that are located in a highrise building pose additional risks due to egress and firefighting challenges.

3.1.5 Mercantile Occupancies

A mercantile occupancy is defined as one that is used for the displaying or selling of retail goods, wares or merchandise.

Larger mercantile occupancies such as department stores are generally occupied by a large number of people and contain high quantities of combustibles in the form of merchandise, furnishings and decorations. Customers may be unfamiliar with the building’s exit locations and not know how to react in the event of an emergency. Additional hazards will be present in “big box” type stores that sell and store large volumes of combustible materials in bulk. These stores generally have similar properties to industrial warehouses with the additional hazard of higher number of occupants.

3.1.6 High/Medium/Low Hazard Industrial Occupancies

An industrial occupancy is defined as one for the assembling, fabricating, manufacturing, processing, repairing or storing of goods and materials. This category is divided into low hazard (F3), medium hazard (F2) and high hazard (F1) based on its combustible content and the potential for rapid fire growth.

These occupancies constitute a special fire hazard due to their high levels of combustible, flammable or explosive content and the possible presence of oxidizing chemicals and gases. Processing and other activities that involve various ignition sources often occur in these occupancies. The lack of security during non-operational hours also makes them susceptible to incendiary type fires. Industrial fires generally involve large quantities of combustible materials and potentially result in large financial losses (e.g. building, contents) and significant damage to the community’s environment and economic well-being (e.g. loss of jobs).

3.1.7 Other Properties

In addition to gathering information on building related risks, attention should also be given to other property types, particularly those that contain large quantities of combustible materials. Propane storage facilities, outdoor tire storage yards, grasslands/forests, plastic recycling depots are examples of properties that could severely impact a community and its environment if involved in a fire. Major highways and railway lines used to transport high volumes of traffic and perhaps large quantities of hazardous chemicals also warrant serious consideration.

3.2 Building Height and Area

3.2.1. Building Height

Taller structures pose unique fire safety concerns and have the potential for significantly greater fire losses over shorter buildings of the same area due to its inherent physical features. The following challenges attributed to taller buildings demonstrate the important role sprinkler protection plays within these structures.

Higher population

Adding additional floors to a building increases the building population, placing more occupants at risk in the event of a fire.

Longer evacuation times

The potential for longer evacuation time exists because egress travel distances from the upper floors increases with building height. The higher number of occupants associated with taller buildings further impacts evacuation time due to the increasing effects of overcrowding and bottlenecking as one descends further down the stairwell. Implementing procedures for occupants that require evacuation assistance or measures for protect-in-place are also considerations for tall buildings.

Communication with building occupants

When an emergency arises, occupants throughout the building need to be notified so that they can take appropriate measures in response to the situation. The importance of timely communications is critical due to the larger population base and the need for a longer evacuation times.

Higher fuel loads

The greater number of floors and higher number of occupants in taller buildings is associated with an increase in the building’s overall fuel load and ignition sources.

Accessing higher floors for firefighting and rescue

Taller buildings pose additional challenges for firefighter access and rescue operations. Travel distances and response times increase, as firefighters need to ascend to higher levels using either the stairwell or elevator. Travel time up the stairs can be further impacted with having to share a crowded stairwell with descending building occupants. Additional challenges also exist for exterior access as fire department aerial apparatus can generally only reach 6 or 7 storeys above ground level.

Stack effect

The stack effect is characterized by the vertical movement of air into and out of buildings due to buoyancy caused by indoor/outdoor temperatures and elevation differences. During the winter heating season, the warmer indoor air rises up the building and escapes through openings in upper storeys . This reduces the pressure at the bottom of the building resulting in cold air infiltration through openings at the base. This effect is reversed during the summer air conditioning season. The stack effect is directly proportional to the structure height. Hence, the taller the building, the higher the smoke distribution rate throughout. A high percentage of deaths that occur within highrise buildings are attributed to toxic smoke inhalation along egress routes.

3.2.2. Building Area

Depending on the occupancy type, some of the aforementioned challenges associated with taller buildings may also be applicable to a sprawling lowrise complex (i.e. higher population, longer evacuation times, communication, higher fuel loads). Large industrial plants/warehouses, greenhouses, farm buildings, department stores/malls, commercial complexes, and care/detention occupancies, to list a few, are often associated with this type of building configuration.

The large areas associated with these buildings pose a different type of challenge for firefighting/rescue operations and occupant evacuation. In this case, high horizontal travel distances to gain access to and evacuate the building are a concern similar to the vertical travel distances associated with highrises. Further, more complicated building layouts can be found in large complexes due to the space allowance for intricate corridor systems, a large number of interior rooms/other spaces, and multiple tenancies/ occupancies.

Even large industrial warehouses that are generally constructed as open concept space can present a concern. The presence of large quantities of combustible piled storage may present a physical hindrance to gaining interior access for firefighting/rescue operations as well as contributing to a significant fuel load.

3.3 Building Age and Construction

A review of the community’s building inventory should be conducted to identify those buildings that may pose a risk due to its age and construction. Generally, older buildings pose a different set of problems than those that have been built to modern construction standards.

3.3.1 Building/Fire Code Application

Prior to the adoption of the OBC in 1975 and the Ontario Fire Code (OFC) in 1981, there were many inconsistencies with how new buildings were constructed and how existing buildings were maintained. Municipalities used their own bylaws to regulate building construction or simply relied on the expertise of architects, engineers and contractors to design and construct safe buildings. After the introduction of the National Building Code (NBC) some municipalities adopted it either in whole or in part. The Office of the Fire Marshal (OFM) also administered construction standards for certain occupancy types between 1958 and 1975.

Current building and fire codes have been developed to provide a uniform and higher level of protection for the Province. Modern codes contain building construction and maintenance standards and requirements that address various fire safety issues including:

  • occupancy
  • building area/height
  • construction materials (combustible vs. non-combustible) for structural and containment
  • exits/means of egress including signs and lighting
  • interior finish flame spread
  • fire protection equipment
  • fire alarm and detection equipment
  • fire department access
  • spatial separations from neighbouring buildings
  • storage arrangements
  • control of ignition sources and combustibles
  • inspection, testing, and maintenance
  • emergency planning

With the introduction of retrofit requirements being first enacted in the OFC beginning in 1983, various types of occupancies including assembly; boarding, lodging and rooming houses; health care facilities; multi-unit residential; two unit residential; and hotel establishments were required to be upgraded to a minimum acceptable level of life safety, over a period of time. Hence a review of the community’s involvement with a retrofit inspection program or specifically a building’s retrofit history in addition to its original construction date, is an important consideration.

3.3.2 Residential Buildings

Historically, residential occupancies have accounted for approximately 70% of all structural fires and 90% of total fire deaths within Ontario. Single-family dwellings (detached, semi-detached and attached homes) combined with multi-unit dwellings (lowrise and highrise buildings) account for over 85% of total residential fires and deaths. Due to the significant fire losses attributed to this occupancy class, the following focuses on construction features relevant to older and newer residential multi-unit buildings and single-family dwellings that may contribute to some of these losses.

3.3.2.1 Multi-unit Lowrise and Highrise Buildings

The OBC and OFC classify residential lowrise buildings as those that are up to and including six storeys in building height, whereas highrise buildings are as those that exceed six storeys. However, Statistics Canada classifies residential lowrise buildings as being less than 5 storeys in height and highrise buildings as 5 storeys or higher. Due to the availability of Statistics Canada building stock data for these classifications, their definition of highrise and lowrise buildings will be used for the purposes of this Section only.

A comparison of Ontario fire loss statistics between residential lowrise and highrise buildings indicate that lowrises have a significantly higher fire loss rate.

Table 4: 2000-2004 Avg. Fire Loss Rates in Residential Multi-Unit Dwellings

Height

Fire Rate per 100,000 Units

Fire Injury Rate per 100,000 Units

Fire Death Rate per 100,000 Units

Lowrise

(<5 storeys)

177

27.3

3.0

Highrise

(5+ storeys)

101

13.8

1.1

Notes:

  1. 2000-2004 Ontario fire loss statistics (Source: OFM Fire Loss Reporting System)
  2. Fire loss rates based on 400,235 lowrise (<5 storeys) dwelling units and 677,800 highrise (5+ storeys) dwelling units in Ontario (Source: 2001 Statistics Canada Census)

The 5-year average shows that lowrise building fire loss rates are 75% higher for fires, 98% higher for injuries and 173% higher for deaths, when compared to highrise buildings.

There are many factors that contribute to this disparity, one of which may be the difference in construction standards between the two. Despite higher residential lowrise fire loss rates, code writers generally perceive highrise buildings to be the greater risk due to their unique fire safety challenges, as previously discussed. These inherent features can potentially lead to significantly more severe fire losses than other types of residential buildings. As a result, both the OBC and OFC contain more stringent construction and retrofit requirements for highrise buildings.

The difference in age between Ontario’s lowrise and highrise building stock is another factor that should be taken into consideration. A review of residential multi-unit dwellings by age of construction reveals that lowrise buildings are generally older than highrise buildings. As of 2001, almost 25% of the province’s lowrise (less than 5 storeys) dwelling units were constructed “pre-1946”, when little if any building construction standards existed. In comparison, only 2.6% of highrise dwelling units were constructed during this period. Conversely, almost 90% of total highrise dwelling units were constructed after 1960, when building code legislation was at least in its early developmental stages. In comparison, only 55% of current lowrise dwelling units were constructed during this period.

Table 5: 2001 Ontario Residential Multi-Unit Dwellings Stock by Period of Construction

Height

1920 & Prior

1945 & Prior

1960 & Prior

1970 & Prior

1980 & Prior

1990 & Prior

2001 & Prior

Lowrise

(<5 storeys)

11.3%

24.2%

45.1%

63.1%

79.1%

92.4%

100%

Highrise

(5+ storeys)

0.8%

2.6%

11.2%

38.7%

69.8%

89.2%

100%

Source: 2001 Statistics Canada Census

Although OFC retrofit requirements bring older residential multi-unit buildings up to an acceptable level of life safety, they are still less stringent than current OBC construction standards from a property protection perspective.

Finally, it is important to note that building construction and age are not the only factors attributed to the significant differences in fire loss rates between residential lowrise and highrise buildings. The other components that make up the Fire Risk sub-model must also be evaluated to determine how they individually impact fire losses with respect to these building configurations.

3.3.2.3 Single-Family Dwellings

Fires in single-family dwellings are responsible for nearly two thirds of all residential fires. Generally, detached homes account for 80% of all single-family dwelling fires, with semi-detached and attached homes evenly contributing to the remaining 20%.

The following table indicates that the overall fire loss rate for single-family dwellings generally fall in between residential lowrise and highrise buildings. The differences in fire rate between the three single-family dwelling types are not significant. However, it is noteworthy that the fire injury and death rates in attached homes are significantly higher than those for detached homes.

Table 6: 2000-2004 Avg. Fire Loss Rates in Single Family Dwellings

Height

Fire Rate per 100,000 Units

Fire Injury Rate per 100,000 Units

Fire Death Rate per 100,000 Units

Detached

139

10.4

1.8

Semi-Detached

151

19.3

0.4

Attached

142

17.2

2.6

SFD-Overall

140

11.9

1.8

Notes:

a) 2000-2004 fire loss statistics (Source: OFM Fire Loss Reporting System)

b) Overall single-family dwelling fire loss rates based on 3,028,470 detached/semi/attached dwelling units in Ontario (Source: 2001 Statistics Canada Census)

c) Detached, semi-detached, attached dwelling fire loss rates based on 2,456,925 detached units, 263,875 semi-detached units, 307,670 attached units in Ontario (Source: 2001 Statistics Canada Census)

Changes in construction features over the years have resulted in improvements from a fire safety perspective. With the introduction of the OBC in 1975, one of the significant changes was the requirement for newly constructed single-family dwellings to be equipped with hard-wired smoke alarms outside all sleeping areas. Smoke alarm requirements have become even more stringent with the OBC requiring them to be installed on all storeys and interconnected with each other. The OFC now requires homeowners to ensure that working smoke alarms are installed on each storey of the home and outside all sleeping areas.

A fire safety concern associated with older single-family residential buildings is the use of balloon frame construction, which was a common framing technique used back in the late 19th and early 20th centuries. This method involved the use of long continuous wood studs to erect walls from the foundation up to the roofline, which created long, concealed, and unobstructed vertical channels. Floor joists were subsequently hung from the wall studs. This type of construction permits fire and smoke to spread rapidly from the lower floors up to the roof level, which also increases the risk of structural collapse. Modern platform framing construction involves constructing wall and floor systems one level at a time. It is an improvement over balloon construction as it provides a horizontal barrier to ensure concealed wall voids do not extend for more than one floor.

In the older downtown sections of some municipalities it is common to find long rows of attached residential/commercial buildings constructed with their attic spaces interconnected with each other. These common attic spaces are often not adequately fire separated from the floor area below within the respective buildings. Hence, this type of configuration allows a fire that originates in one building to rapidly spread to the adjacent ones and potentially impacting an entire city block. Current building code regulations address this concern by requiring the construction of a firewall or party wall between attached buildings to provide a continuous vertical separation from the foundation footings up to at least the underside of the roof deck.

The interior walls and ceilings in older homes are often finished with combustible materials such as wood paneling and plastic acoustic ceiling tiles. These contribute to rapid horizontal and vertical fire spread and can be a major factor contributing to flashover and the speed with which exit pathways become unusable. The use of drywall for interior wall and ceiling construction is more common in newer construction. Although acoustic ceiling tiles are still found in many newer homes, particularly in finished basements, many current manufacturers incorporate fire retardant features into these products.

Other fire safety improvements associated with current building construction practices include the use of flame retardant chemicals on cellulose insulation, more stringent chimney construction standards, and improved electrical wiring systems to support the electrical loads of modern appliances.

The following table provides a summary of Ontario’s single-family dwellings based on period of construction. The age of detached and semi-detached dwellings are fairly similar, with 19.2% of detached and 23.7% of attached dwellings constructed “pre-1946”, when little if any building construction standards existed. Attached dwellings are comparatively newer as the majority of them were constructed after 1980, with only 5.2% constructed “pre-1946”.

Table 7: 2001 Ontario Single-Family Dwellings Stock by Period of Construction

Height

1920 & Prior

1945 & Prior

1960 & Prior

1970 & Prior

1980 & Prior

1990 & Prior

2001 & Prior

Detached Dwellings

9.9%

19.2%

38.8%

52.2%

67%

85.3%

100%

Semi-Detached

12.2%

23.7%

35.8%

50.9%

74.1%

84.7%

100%

Attached Dwellings

3.1%

5.2%

9.8%

21.7%

48.4%

70.9%

100%

Source: 2001 Statistics Canada Census

3.4 Building Exposures

High building density within the community, such as those that are typically found in older downtown sections, and areas where there has been “infill construction” are particularly at risk to exposure fires involving multiple buildings due to their close proximity to each other. Further, the limited distances between buildings may hinder fire department access, as only the side(s) of the buildings facing streets may be accessible by firefighting apparatus.

An exposure fire is one in which a fire originating in the building creates an external fire hazard to neighbouring structures by exposing them to heat and flames. Heat can be transferred by radiation and convection through wall openings, direct flame impingement or flying embers. The smaller the separation distance between buildings, the higher is the potential risk for an exposure fire. Past experience has demonstrated that exposure fires can occur despite separation distances of up to 30 m from the exposing fire.

As these are existing structures, there is very little that can be done with respect to physically increasing the separation distances between them. However, an understanding of the factors that influence the severity of an exposure fire may assist with identifying appropriate measures that can mitigate its impact if one should occur. With respect to the originating or exposing building fire, these factors include:

  • Temperature and duration of exposing fire
  • Type of exposing and exposed exterior wall and roof construction
  • Width and height of exposing fire
  • Percentage of openings in exposing and exposed wall area
  • Protection of openings
  • Exterior wall surface areas and orientation with respect to each other
  • Exposure of interior finish and combustibles to exposing fire
  • Burning room characteristics (ventilation, fuel, size, geometry)
  • Interior finish and building content thermal properties in both buildings
  • Sprinkler protection availability
  • Early detection and fire department notification

Some of the means of providing building protection to mitigate the effects of exposure fires include:

  • Providing automatic sprinkler protection
  • Constructing firewalls between buildings
  • Installing automatic exterior water curtains for windows and combustible walls
  • Closing or providing protection for wall openings (i.e. glass block panels, wired glass, automatic fire shutters/fire doors/dampers)

3.5 Demographics Profile

Different demographic groups can pose unique fire safety challenges. Community population and population shifts throughout the day or year will also introduce varying demand for fire protection services. Developing a community demographic profile is essential to gaining insight on the population being protected. Demographic information to be identified include:

  • Population Distribution by Age
  • Population Shifts
  • Vulnerable Individuals or Occupancies
  • Language Barriers to Public Education
  • Income Levels
3.5.1 Population Distribution by Age

Establishing a population profile based on age distribution can assist in identifying the extent of vulnerable residents within a community.

The risk of fire deaths associated with a particular age segment can be determined by calculating and comparing the fire death rates for various age segments associated with a particular location.

Fire Death Rate = (Number of fire deaths associated with age segment x 1,000,000) / population associated with age segment

The following chart compares the death rate by age in Ontario over a 5-year period.

Chart 1: Ontario Fire Death Rate by Age

Chart showing how at the age category 50 to 64, the fire death rate begins to climb above the overall population’s risk level of 8.4 deaths per million population and continues to rise exponentially to a rate of 33.3 at age 85 and over.

As identified in the chart, at the age category 50 to 64, the fire death rate begins to climb above the overall population’s risk level of 8.4 deaths per million population and continues to rise exponentially to a rate of 33.3 at age 85 and over.

The above data can be refined by determining each age category’s “Fire Death Risk Index” (FDRI). This index is calculated by dividing the death rate for each age segment by the overall death rate of the entire population. An FDRI for an age group that is above 1.0 indicates that they are riskier than average and conversely, one that is below 1.0 indicates that they are below average risk.

The following chart compares the FDRI by Age in Ontario over a 5-year period.

Chart 2: Ontario Fire Death Risk Index by Age

Chart showing how, at the age category 50 to 64, the fire death risk begins to rise above the overall risk, ascending exponentially to a risk level that is 4 times higher than the per capita rate at age 85 and over.

Similar to the previous chart, at the age category 50 to 64, the fire death risk begins to rise above the overall risk, ascending exponentially to a risk level that is 4 times higher than the per capita rate at age 85 and over. This method provides a simpler way of comparing risk levels between age segments.

3.5.1.1 Older Adults

One of the most significant demographic trends in Canada today is the aging of the general population. In 2001, one in eight Canadians was aged 65 years or over. By 2026, one in every five Canadians will have reached age 65. The reasons for this trend are complex but include factors such as the impact of the "baby boomer" generation and increases in life expectancy due to medical advances.

As seen in the above statistics, older adults represent one of the highest fire risk target groups in Ontario. The aging process is linked to the decline in an individual’s physical and cognitive ability, which reduces their reaction time during a fire emergency. The effects of aging may often be compounded due to illness, disabilities, hearing/sight impairments, and the effects of prescription medication. Physiologically, they are more susceptible to injury and death when exposed to fire or smoke. All of these factors result in the decreased likelihood that an older adult will survive a fire if involved in one.

Between 2000 and 2004 the leading causes of senior (aged 65 and over) fire deaths were attributed to “open flame tools/smoker’s articles” and “cooking equipment”. These ignition sources were responsible for 35% and 10% respectively of fire deaths for this age category during this period. It is believed that the decline in cognitive and physical abilities contributes to the frequency of fire incidents relating to the careless use of these ignition sources.

Unless measures are taken to mitigate risks associated with this target group, fire deaths associated with older adults will continue to increase in proportion to their rapidly growing population.

3.5.1.2 Children

Fire death statistics for children under the age of 10 indicates that this group has a relative risk similar to that of the general population. Despite this, it is generally recognized that children, particularly those that are under the age of 5, are one of the most vulnerable groups within the general population. This is because they are dependent on adults for their safety due to their undeveloped cognitive and physical abilities and general lack of maturity. They are unable to recognize a hazardous situation and take the necessary actions to escape on their own. Physiologically, they are more susceptible to injury and death when exposed to fire or smoke.

It is also recognized that children are a risk with respect to initiating fires. Younger children are naturally curious and will often touch and amuse themselves with items that are within their reach. This includes playing with ignition sources such as matches, lighters, candles, stoves and fireworks, without understanding the consequences. Between 2000 and 2004, “Open flame tools/smoker’s articles” were determined to be responsible for 28% of fire deaths related to children under the age of 10. Incendiary fire incidents are often linked to older children. It is estimated that over 50% of incendiary fires investigated by the OFM are motivated by mischief or vandalism and started by young people.

3.5.2 Population Shifts

The population of the community can vary significantly throughout the year, which can impact the demand for fire protection services. A tourist or cottage community that attracts many vacationers during the summer will have inflated populations during this period. Some communities may host large annual events that may draw a sudden influx of visitors for a short period of time. In contrast, university/college towns may have a higher population base during the school months than during the summer months.

The population within the community may also vary significantly throughout the day due to its residential and employment characteristics. One that is characterized as a “bedroom community”, in which the vast majority of the residents leave town to go to work, will have a reduced population level during the daytime as compared to the evenings. In contrast, an “industrial town” that employs a high number of people during daytime work hours but is home to only a few during the evening hours, will have the opposite effect.

3.5.3 Vulnerable Individuals or Occupancies

Determining the extent and location of vulnerable and non-ambulatory occupants within the community should be given a high priority. Occupants with vulnerabilities due to age related limitations were discussed earlier. However, it is also recognized that there are occupants with vulnerabilities associated with physical/cognitive limitations, disabilities, drug or alcohol use, that require evacuation assistance in the event of a fire emergency. Special consideration should be given to identifying locations such as hospitals, senior’s apartments, group homes, rooming houses, residential care, long-term care homes, and children’s daycares and student dormitories.

3.5.4 Language Barriers to Public Education

Ontario is an ethnically diverse province with 54% of the population reporting origins other than British, French or Canadian. A 1996 Canadian Heritage Multiculturalism report identified 15 different languages, other than English and French, that are commonly spoken in Ontario homes.

This language diversity issue can present challenges with respect to effectively providing public education information and programs to the community through the media, written materials, telephone inquiries and seminars. A review of the community’s ethnic profile is necessary to determine whether language barriers to public education exist. If so, it will be necessary to develop communication strategies to ensure public safety messages are effectively passed on to the target audience.

3.5.5 Income Levels

The “2005-2006 Ontario Stovetop Fire Survey” conducted by the OFM on cooking fires revealed that the stovetop fire incident rate in subsidized residential dwellings was three times higher than non-subsidized dwellings. This finding suggests that there is a correlation between income levels and fire risk.

In Ontario, 14.5% of the population earn below Statistics Canada’s “Low Income Cut-Off After Tax” measure, which is a widely accepted poverty benchmark. In the U.S., the study of socioeconomic factors is recognized as being among the best-known predictors of fire rates at the community level. In particular, the 1997 Federal Emergency Management Agency (FEMA) report, “Socioeconomic Factors and the Incidence of Fire” and the 1989 NFPA Journal article, “How Being Poor Affects Fire Risk” have shown that there is a close link between income levels and fire risk. These reports demonstrate this relationship by identifying the following factors:

  • The higher number of vacant buildings found in low-income neighborhoods attract the homeless. This introduces risks such as careless smoking, drinking and unsafe heating practices.
  • Building owners are less likely to repair building systems (electrical, mechanical) due to affordability, increasing fire risk from improper maintenance.
  • Households with lower disposable income are less likely to purchase fire safety products (i.e. smoke alarms, extinguishers, cigarette ignition resistant furniture, etc.) due to affordability.
  • Households with lower disposable income are more likely to have their utilities shut off due to non-payment, leading to increased risks related to unsafe heating, lighting and cooking practices.
  • The 1981 report, “Fire-Cause Patterns for Different Socioeconomic Neighborhoods in Toledo, Ohio” determined that the incendiary fire rate in low-income neighbourhoods is 14.4 times higher compared to areas with the highest median income. Further, fires caused by smoking and children playing occurred at rates 8.5 and 14.2 times higher, respectively.
  • Single parent families are more economically challenged due to the fact that there is only one income. These households also have fewer resources to arrange childcare, increasing the likelihood of fires caused by unsupervised children.
  • Studies have shown that cigarette smoking is inversely related to income. In Canada, findings by the Centre for Chronic Disease Prevention and Control through the National Population Health Survey established that there were nearly twice as many smokers in the lowest income group when compared against the highest (38% vs. 21% respectively).
  • Those with low education and literacy levels are inhibited in their ability to read instruction manuals and warning labels and less likely to grasp fire safety messages.

3.6 Geography/Topography/Road Infrastructure

The geography, topography, and transportation infrastructure that exist within the community can impact the fire department’s ability to promptly respond to an emergency. Areas that are prone to severe weather conditions can further compound any concerns. These need to be evaluated to identify what factors can potentially impede responses to various locations so that measures can be taken to address these obstacles. The goal is to ensure that the fire department is capable of responding to an emergency anywhere within the community at anytime within a reasonable time.

3.6.1 Roads and Access Routes

Consideration needs to be given to the road conditions and private property access routes within the community. Are they properly maintained and accessible throughout the year? Are they wide enough and constructed well enough to support the width and weight of a fire department vehicle? How are “unassumed” roads within new residential subdivisions, that are in poor condition and obstructed by construction vehicles/materials, dealt with? Are there railway crossings and drawbridges along response routes that can potentially result in lengthy delays? Which roads have reduced lanes or are closed due to construction? How will severe weather, particularly during the winter season, impact these travel routes?

3.6.2 Traffic Pattern

Variations in traffic patterns, particularly in an urban community will impact response times. Is the community prone to traffic congestion during the morning and afternoon rush hour periods? How do traffic conditions vary during the course of the year due to weather, road construction or population fluctuations? A review of normal traffic patterns and street design can reveal strategic information on what are the most efficient routes to take during these peak demand periods.

3.6.3 Natural Terrain

The natural geography and topography inherent to the community may impact response times to certain areas of the population. How would the terrain be characterized within the community? Are there any difficult to access areas such as those located on hilly or low-lying flood susceptible terrains? Are there any remote properties that are isolated by a watercourse (i.e. islands) or forests/wildland? Consideration must be given to these secluded and potentially difficult to access areas to ensure that adequate resources are in place to protect them.

3.7 Past Fire Loss Statistics

A historical review of the number and types of fire losses that have occurred over the past number of years can highlight the risks, trends and patterns that have been prevalent within the community.

The review should include data such as the number of fire incidents, casualties (injuries and fatalities), and monetary property losses associated with the various reporting fields within the OFM’s Standard Incident Report and Casualty Report. Some categories that may be useful for analysis may include losses associated with:

  • Occupancy type
  • Casualty age
  • Casualty action
  • Ignition source
  • Cause of fire
  • Area of origin
  • Presence/operation of detection and suppression devices
  • Fire frequency based on area/sub-area to determine local patterns
  • Time of occurrence
  • Response times

More often than not, a combination of the above categories will yield the most useful information.

Analyzing this data based on general population or a specific vulnerable segment of the population can provide more meaningful results for comparison purposes. For example, annual fire/death/dollar loss data provides general information on the community. However, this information is less relevant when compared to statistics from a municipality that has a vastly different population. If this data is expressed based on a population rate, this becomes more practical for comparison purposes. Comparing fire loss rates based on a specific segment of the population can provide even further insight. Property stock and population data will assist with this exercise. This type of analysis can form the basis for establishing the likelihood levels of certain types of events.

Table 8: Industrial Fire Analysis

Rating

Measure

General

Annual number of industrial fires

Specific

Annual industrial fire rate per 100,000 population

More Specific

Annual industrial fire rate per 1,000 industrial buildings

Table 9: Residential Senior Fire Injuries Analysis

Rating

Measure

General

Annual number of residential senior (age 65+) fire injuries

Specific

Annual residential senior fire injury rate per 100,000 general population

More Specific

Annual residential senior fire injury rate per 100,000 senior population

Determining the nature of the fire problem in the community is the first step in identifying the most effective remedy. Once established, the appropriate resources and programs can be specifically targeted to address these concerns.

3.8 Fuel Load

The quantity and chemical nature of combustible fuel load within a compartment in combination with the availability of oxygen/air influences the rate at which a fire burns and the total amount of energy released. This in turn establishes the fire’s potential intensity and duration prior to the fuel being depleted.

In a typical building the fuel load includes its combustible content, interior finish, floor finish and structural elements. Generally, it is the combustible content within the building that creates the fire problem. Typical fuel load found in most buildings include paper, clothing, furniture, window coverings, office equipment, wall/floor finishes, decorative items, combustible gases and flammable/combustible liquid based products. The quantity levels and types of combustible content will vary based on building occupancy type and its population.

The burning rate of a given fuel is dependent on its chemical makeup and physical geometry. In general, petrochemical based products such as those manufactured from plastics and flammable/combustible liquids release heat at a higher rate than cellulosic materials such as wood, paper, cotton, and fabric. Petrochemical based products also generate more toxic and smokier combustion products. The physical geometry of the fuel based on its surface area to mass ratio will influence how well it burns.

Although all buildings contain a fuel load in one form or another, of particular concern are those that store or manufacture large quantities of combustible products that emit toxic combustion products when ignited. Examples are industrial properties such as waste transfer/recycling facilities, plastic storage warehouses, and manufacturers of flammable/combustible liquids based products. Large fires involving these facilities can result in significant impact to the local environment.

Buildings with exceptionally high fuel content are not limited to industrial occupancies. Mercantile occupancies such as malls and “big box” warehouse type stores carry significant quantities of combustible merchandise. Assembly occupancies such as nightclubs and bars can have a significant amount of combustible furniture, decorative materials on walls/ceilings and alcohol (flammable liquid) within a relatively small area. Office buildings are generally associated with considerable fuel loads in the form of combustible furniture, office equipment and supplies.

In general, buildings with higher fuel loads are at greater risk due to the increased opportunity for ignition and higher potential for a more severe fire. Providing sprinkler protection is an effective means of mitigating the effects of fire in these locations.

4.0 Assessing Fire Risk Scenarios

For analysis purposes, the community being assessed can be defined as the municipality in its entirety or as a particular segment of it that distinguishes it from other parts. For smaller municipalities, it may be sufficient to simply define the community based on town boundaries. For larger municipalities, it may be appropriate to subdivide it into separate and distinct components to permit a more detailed analysis. For example, it may be convenient to subdivide a municipality based on residential subdivision, downtown sections, industrial park, and a rural area. Hence, the first step in conducting a fire risk analysis is to identify and define the community(s) being analyzed.

The second step involves assessing the community(ies) based on the eight risk factors and compiling a list of potential fire risk concerns associated with these. The following sample Community Fire Risk Profile is provided to illustrate this process for a community that has been defined based on its municipal boundaries.

Table 10: Sample Community Fire Risk Profile

Risk Factors

Concerns

  1. Property Stock
  • 2 multi-unit residential buildings
  • A hospital and 2 nursing homes
  • Industrial park consisting of various industrial buildings including a large plastics storage warehouse
  • Aging downtown core consisting of mixed residential/commercial buildings
  • A rural property with excessive outdoor storage of waste rubber tires
  1. Building Height and Area
  • First multi-unit residential building is 8 storeys in height
  • Second multi-unit residential building is 5 storeys in height
  • Hospital is 3 storeys in height
  • Both nursing homes are 2 storeys in height
  1. Building Age and Construction
  • Downtown core buildings were constructed in early 1900’s prior to NBC and OBC.
  • Neither of residential multi-unit buildings meet retrofit requirements under Part 9 of the Fire Code due to owner non-compliance
  1. Building Exposures
  • Downtown core building are closely constructed or attached to each other
  1. Demographic Profile
  • 10% of the population identified as non-English speaking
  • 20% of the population identified as senior citizens over the age of 65
  • Vulnerable residents in hospital and nursing homes
  1. Geography/ Topography/ Road Infrastructure
  • Congested traffic throughout community during morning and evening rush hour
  • Excess of 12 minutes FD response time to certain properties located in rural area
  • New subdivision under construction with unpaved roads that are often blocked with construction vehicles and materials
  1. Past Fire Loss Statistics
  • Annual residential fire rate (fires per 1000 residential buildings) exceed provincial average in each of the past 4 years. This is the case even when compared with similar sized communities.
  • At least one senior citizen fire death in each of the past 7 years
  • Major plastics warehouse fire 10 years ago resulting in partial community evacuation
  • A few cases of arson over the past 6 months in one particular residential subdivision.
  1. Fuel Load
  • Large quantities of combustible material in plastics recycling plant
  • Approximately 5,000 rubber tires stored on outdoor rural property

The third step involves reviewing and analyzing the individual concerns independently or in combination with others to develop potential fire risk scenarios. For example, a risk factor involving the presence of a residential highrise building creates the simple risk scenario of “a fire originating in a residential highrise building”. However, there may be situations where it would be appropriate to combine two or more risk factors to accurately reflect an existing condition. Expanding on this example, the presence of a residential highrise building that is primarily occupied by non-English speaking senior citizens and does not meet retrofit requirements, introduces additional concerns. This produces a more complex scenario that is riskier than the original one. The ability to combine individual factors to generate these multi-risk scenarios requires one to have in-depth local knowledge on how these issues interact with each other.

The fourth step involves assessing and assigning probability and consequence levels to each of the potential fire risk scenarios. Guidance on establishing these levels was previously discussed in Sections 2.2 and 2.3.

The fifth step involves applying a Risk Analysis Matrix to each of the potential fire risk scenarios to determine overall risk for the purposes of prioritizing management decisions. Guidance on the use of this tool was previously discussed in Section 2.4.

The following sample scenarios are provided to illustrate the application of the Risk Analysis Matrix:

Table 11: Sample Fire Risk Scenario Assessment

Fire Risk Scenario

Prob. Level

Conseq. Level

Overall Risk Level

Priority Level

  1. A grass fire in an open field located in the municipality’s outskirts

4

1

Moderate

L2

  1. A residential lowrise fire that does not meet retrofit requirements and is primarily occupied by senior citizens

3

4

Extreme

L4

  1. A fire originating in a large unsprinklered warehouse that stores large quantities of plastics material is located within 1 km upwind of a residential subdivision

2

4

High

L3

Note: The assigned probability/consequence levels for the above sample scenarios are provided for illustration purposes only. These are subjective measures that can vary based on individual circumstances surrounding a community.

5.0 Summary

Assessing a community to determine its inherent fire risks is a fundamental exercise for establishing the types of scenarios that may be encountered. The outcomes derived by the exercise serve as the basis for formulating and prioritizing fire risk management decisions to reduce the likelihood and adverse impact of these events.

In summary, assessing the fire risk within a community consists of:

  1. Defining the community boundaries.
  2. Assessing how the 8 key factors contribute to a community’s inherent characteristics and circumstances.
  3. Compiling a list of potential fire risk scenarios.
  4. Assigning probability and consequence levels to each scenario.
  5. Applying the Risk Analysis Matrix to establish overall risk levels for each scenario to prioritize management decisions.

The following chart summarizes how the Fire Risk Sub-Model fits into the Comprehensive Fire Safety Effectiveness Model.

Chart 3: Fire Risk Sub-Model

Chart outlining how the Fire-risk sub-model relates to the Comprehensive Fire Safety Effectiveness Model

Appendix A: References

  • SFPE Engineering Guide to Application of Risk Assessment in Fire Protection Design-Review Draft, October 2005
  • AS/NZS 4360: 1999-Risk Management
  • OFM PFSG 01-02-01: Comprehensive Fire Safety Effectiveness Model Considerations For Fire Protection & Prevention In Your Community
  • OFM PFSG 02-02-12: Risk Assessment
  • OFM PFSG 04-39-12: Fire Prevention Effectiveness Model
  • OFM PFSG 04-40A-12: Simplified Risk Assessment
  • OFM Shaping Fire Safe Communities-Field Guide
  • CAN/CSA-Q850-97-Risk Management: Guideline for Decision-Makers
  • NFPA 550-Guide to the Fire Safety Concepts Tree
  • NFPA 551-Guide for the Evaluation of Fire Risk Assessments
  • NFPA Guidance Document for Incorporating Risk Concepts into NFPA Codes and Standards
  • FEMA: Topical Fire Research Series: Highrise Fires
  • FEMA: Topical Fire Research Series: The Fire Risk to Older Adults
  • FEMA: Topical Fire Research Series: The Fire Risk to Children
  • Fire Safety in High-rise Apartment Buildings-Fire Technologies Inc., OAA, CMHC
  • Report of the Public Inquiry into Fire Safety in Highrise Buildings
  • A Socio/Economic Impact Analysis of the Proposed Lowrise Residential Retrofit Legislation
  • Low Rise Residential Retrofit Study
  • Emergency Management Ontario-Community Emergency Management Coordinator Handbook
  • Canadian Heritage Multiculturalism-Multicultural Canada: A Demographic Overview, 1996
  • NFPA Fire Protection Handbook: Various sections
  • The SFPE Handbook of Fire Protection Engineering: Section 5/Chapter 1 Introduction to Fire Risk Analysis
  • FEMA: Socioeconomic Factors and the Incidence of Fire
  • Fire Journal (1989): “How Being Poor Affects Fire Risk”
  • OFM: 2005-2006 Ontario Stovetop Fire Survey
  • A Poverty Reduction Strategy for Ontario (Ontario Campaign 2000 Discussion Paper-July 2007)
  • Public Health Agency of Canada-Centre for Chronic Disease Prevention and Control “National Population Health Survey Highlights”
  • European Journal of Epidemiology-“Health Behaviours and Socio-Economic Status in Ontario, Canada”