Ministry of the
Solicitor General

Hazard Identification Report 2019 - Section D - Hazardous Materials Hazards


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Hazard Identification and Risk Assessment Program

Hazard Identification Report 2019
Section D: Hazardous Materials Hazards

Office of the Fire Marshal & Emergency Management


The Hazard Report contains information profiles for hazards, including a high-level overview of possible consequences. It is divided into 10 parts; an introduction and 9 sub-sections labelled A-I as follows:

  1. Agriculture and Food
  2. Environmental
  3. Extraterrestrial
  4. Hazardous Materials
  5. Health
  6. Public Safety
  7. Structural
  8. Supply and Distribution
  9. Transportation

Hazardous Materials Incident: the unintentional release of a material that is considered to be hazardous to humans, animals, plants or the environment due to its explosive, flammable, combustible, corrosive, oxidizing, toxic, infectious or radioactive properties.

  • Fixed Site Incident: A release occurs at a location in which the hazardous material is stored, produced or utilized.
  • Transportation Incident: A release occurs during the transport (by means of road, rail, air or marine).

Potentially hazardous materials are used every day across Ontario. Every community has at least one facility that stores, produces or utilizes a hazardous material. These facilities include water treatment plants, textiles manufactures, dry cleaners and even schools. When properly contained and stored, hazardous materials are stable and safe. However, hazardous materials can have a variety of negative impacts depending on the type of material.

There are many national and provincial regulations designed to reduce the risk of hazardous materials. Among these, the most significant are:

  • Transportation of Dangerous Goods Act, 1992 (1992, c. 34)
  • Fire Protection and Prevention Act, 1997, S.O. 1997, c. 4
  • Ontario Occupational Health and Safety Act and O. Reg 860
  • Canadian Environmental Protection Act S.C. 1999, c. 33

Chemical Release

Go to next hazard: Nuclear Emergency


A chemical release is defined as the uncontrolled release of a hazardous chemical, either as a solid, liquid or a gas.[1]


Chemicals are used for many processes common in day-to-day life. Many different types are used, manufactured, generated as by-products, imported and exported in Ontario on a daily basis[2] and via all modes of transportation. This includes the Great Lakes, the St. Clair River and the St. Lawrence Seaway marine transportation routes.[3]

Ontario has the largest chemical industry of any province in Canada, with greater than 26,000 employees and more than $16 billion in shipments.[4] Products include plastics, basic organic and inorganic chemicals, synthetic resins, fertilizers, pharmaceuticals and many others.

Measures used to mitigate risk for this hazard include, but are not limited to:[5]

  • strict regulation of personal protective equipment for employees working with chemicals;
  • regulation of the industrial use of hazardous chemicals, to prevent releases and respond to them when they do occur; and
  • regulation of how chemicals are shipped in Canada.

Chemical pollution presents a host of dangers to plants and animals. Some chemicals can pose an immediate threat to human lives, whether through toxic clouds, corrosive spills, fire, explosions, or other means. Longer-term health effects are also possible, including mutagenic and carcinogenic effects. Toxic spills can kill wildlife, destroy habitat, and contaminate critical resources in the food chain.[6]

Triggers for chemical release can include:

  • Explosion/Fire
  • Structure Failure
  • Transportation incident (e.g. derailment)
  • Environmental hazards

Heavily industrialized areas experience a greater risk of a Chemical emergency than other locations. However, almost every community in Ontario has at least one facility that stores, produces or utilizes chemicals.[7] The Ministry of the Environment, Conservation and Parks, Spills Action Centre, handles reports of spills, adverse drinking water results, and other urgent environmental concerns, and receives approximately 4,000 reports of spills every year. Nearly two-thirds (63.4%) of Canadian incidents in 2016 occurred in facilities such as terminals or warehouses, while road incidents accounted for about one-third (33.1%) of incidents.[8] The majority of releases are relatively minor with no serious or long-term impacts, and are usually handled by the organization responsible or the municipality.

Reporting obligations under different Acts can be numerous and overlapping For example, a spill may need to be reported under the Ontario Water Resources Act but exempted from the Environmental Protection Act, or it may be reportable under both. It is therefore important for emergency management coordinators to also understand the potential reputational and legal implications of chemical use and spills, to better know the local context of risk associated with this hazard.

Emergency Managers should be aware of what industries use chemicals within their jurisdiction. They should also be familiar with the basics of transportation incident response. The Transport Canada and the US Department of Transportation’s Emergency Response Guidebook is a good starting point for such information.[9]

Spatial Scale, Timing and Warning Period

Spatial Scale: The scale of the incident depends on the source and type of chemical, atmospheric conditions and exposure.

Timing: There is no particular season in which chemical emergencies are more likely. Hundreds of thousands of hazardous materials shipments move through Ontario annually.[10] Shipments and storage can occur at any time, day or night.

Warning Period: The amount of warning varies depending on the situation, though generally chemical spills happen with no advanced warning and an immediate need for remedial action.

Potential impacts

Specific impacts are unique, and depend on a variety of factors, from chemical type to the circumstances of release. These include:

  • The need for evacuation or shelter in place.
  • Enactment of milk, water, and foodstuff consumption bans
  • Risk to public health, including contamination through the environment, potable water, food, animal products and other vectors.
  • Illness or death. May strain the health system and response resources.
  • Long-term population health monitoring.
  • Ecosystem damage or disruption. Need for assurance monitoring of the environment.
  • The need for evacuation or shelter in place.
  • The need for site or area access restrictions.

Secondary Hazards

Secondary hazards that can occur as a result of chemical releases include:

  • Fire/Explosion
  • Food Contamination
  • Geopolitical Pressures
  • Water Quality

Past Incidents

There are routine incidents involving chemical spills on a daily basis. Significant events after 1990 include:[11]

  • Dryden, 2002: A chlorine dioxide leak at a nearby paper mill caused 300 to 400 people to be evacuated from the downwind area.
  • Sudbury, 1995: A cloud of sulphur dioxide was accidentally released from a copper refinery and passed over a part of the city.
  • Longlac, 1992: A freight train carrying 4 ammonia cars derailed causing a small leak in two of the cars.
  • Sarnia, 1992: Issue with a heat exchanger unit caused the release of 1500 kg of isobutylene to the St. Clair River in two consecutive spills.
  • Corunna, 1992: Abnormal discharge from a refinery of approximately 1000 kg of benzene, toluene and xylene into a sewer which drains to Telford Creek and St. Clair River; Wallaceburg and Walpole drinking water intakes were both closed for two days.
  • Cochrane, 1991: Failure and explosion of a section of pipeline.

Perhaps the most memorable and high-profile chemical spill resulted as a secondary effect of the 1979 train derailment in Mississauga. The train was carrying propane, styrene, toluene, caustic soda and chlorine and resulted in a large explosion and fire. The forced evacuation of 225,000 people is the second-largest in North American history, second only to New Orleans in 2005.

Provincial Risk Statement

There are tens of thousands of chemical sources in Ontario in research facilities, universities, industry and medical buildings. These substances are also transported throughout the province. Incidents involving releases happen regularly, but are usually very limited in reach of impact, duration, and affected population.

The City of Sarnia has the largest cluster of facilities that produce or use large quantities of chemicals in Canada. There are forty-six facilities that are listed in the National Pollutant Release Inventory within 25 km of Sarnia, with more on the United States side of the border.[12] Two other areas identified by the Ontario Government as having a large concentration of chemical companies are the Greater Toronto Area and Eastern Ontario.

Human Impacts

In general, human exposure is very limited, due in part to a large variety of measures to control and limit the exposure of people, animals and the environment.

A chemical exposure can produce a health effect directly at the site of contact (local) or elsewhere in the body (systemic), and that effect can be either immediate or delayed.

Social impacts

Concern and anxiety, as well as protective directions leading to social isolation or fragmentation of communities, could create real and perceived threats to community social support networks and support systems.

Property Damage

The contamination of property, and the corrosive, explosive, or flammable nature of some chemicals, poses a risk. This may result in structures becoming unusable for a time or needing to be permanently closed, it also increases the risk of fire/explosions and structural failure.

Critical Infrastructure Disruptions

Critical infrastructure disruptions may occur due to an unplanned or unexpected release of chemicals that may contaminate infrastructure and take it out of use.

A release could contaminate the water supply and result in significant environmental damage depending on the type and the amount of material released.

The need for specialized decontamination and healthcare in the event of a chemical incident would put additional stress on the healthcare system. Additional stress on these systems may arise from widespread public anxiety about exposure.

Environmental Damage

Depending on the level and type of contamination, clean-up of ground, water or other environmental contamination may be necessary. If it is severe, any inhabitants of that site may require relocation.


Chemical release can also effect the local economic activities including forcing the closure of fisheries, driving away tourists, or temporarily shutting down transportation routes. Environmental and economic damages can linger for decades.

Nuclear Emergency

Go to previous hazard: Chemical Release

Go to next hazard: Oil or Natural Gas Release


The source of a 'Nuclear Emergency' is a reactor facility, unlike radiological emergencies.

A Nuclear Emergency is an emergency that has led to or could lead to the release of radioactive material, or exposures to uncontrolled sources of radiation, which pose, or could pose, a threat to health and safety, property, and the environment.[13][14]


A reactor facility is a location producing greater than 10 megawatts gross thermal energy (MWth) from nuclear fuel and consisting of one or more reactor units. This includes nuclear power plants and research reactors greater than 10 megawatts gross thermal energy.

Ontario Reactor facilities such as the Pickering, Darlington, and Bruce stations produce electricity created by nuclear fission. Nuclear fission generates heat. This heat boils water to produce steam that can then be used to power turbines which generates electricity. These and one other reactor are included in the Ontario Provincial Nuclear Emergency Response Plan (PNERP):[15]

  • Pickering Nuclear Generating Station has six operating CANDU® (CANadian Deuterium Uranium) reactors with a total output of 3,100 megawatts of electrical energy (MWe) which is enough to serve about 14 per cent of Ontario’s electricity needs.[16]
  • Darlington Nuclear Generating Station has four operating CANDU reactors with a net output of 3,512 megawatts (MWe). Located in the Municipality of Clarington in Durham Region, Darlington Nuclear provides about 20 per cent of Ontario's electricity needs.[17]
  • Bruce Nuclear Generating Station is located in the communities of Inverhuron and Tiverton, Ontario. The CANDU facility has eight reactors arranged into two plants (A and B) with four reactors each. Its total output is 6,232 megawatts (MWe). [18]
  • FERMI 2: FERMI 2 is a Boiling Water Reactor (BWR) - a type of light water nuclear reactor used for the generation of electrical power. It is located in Frenchtown Charter Township, Michigan. All units of the plant are operated by the DTE Energy Electric Company and owned (100 percent) by parent company DTE Energy.

The Canadian Nuclear Safety Commission (CNSC) monitors the safe operation of reactor facilities in Canada, issues licences to operate stations, approves station-specific (on-site) emergency response procedures, and enforces station compliance with the Nuclear Safety and Control Act.

The emergency management office, within the Ontario Ministry of the Solicitor General, is responsible for off-site emergency response activities. The Provincial Nuclear Emergency Response Plan (PNERP) Master Plan and its site specific implementing plans provide the framework for managing nuclear emergency response in Ontario. Implementing plans address nuclear emergencies at each reactor facility, as well as plans to address trans-border and other radiological emergencies. While the NRU Research Reactor at Chalk River Laboratories does not meet the definition of ‘reactor facility’, the PNERP currently also includes an implementing plan for this location.

A number of municipalities, designated by the PNERP, must also develop their own Nuclear emergency response plan that details actions to be followed by that municipality in the event of a Nuclear emergency (such as evacuation).

The structure for nuclear and radiological emergency response planning in Ontario includes:

  • Emergency Management and Civil Protection Act (EMCPA): Requires and authorizes the formulation of the plan.
  • Provincial Nuclear Emergency Response Plan (PNERP): Developed pursuant to Section 8 of the EMCPA and subject to Cabinet approval.

The Government of Ontario also leads a Nuclear Emergency Management Coordinating Committee (NEMCC) to ensure an optimum state of nuclear emergency planning, preparedness, response and recovery in Ontario. In addition to these measures, established working groups and sub-committees enhance the consistency and coordination of planning nuclear response activities in Ontario.

The emergency management office considers all potential accidents, including those considered severe, as a part of the risk analysis and planning basis for Ontario. While severe accidents are highly unlikely to occur, they, along with less severe accidents that have a higher probability of occurring, are given due consideration during the preparedness phase. The most likely scenario considered in the PNERP falls within a ‘design-basis accident’ (DBA), which consists of the following:

  • Station containment systems function normally allowing radiation to decay prior to a controlled release.
  • Sufficient time would be available to alert the public and implement protective measures prior to a release.
  • The main radiological hazard to people would be external exposure to, and inhalation of, radionuclides.
  • Filter systems function to remove almost all of the radioiodine. As a result, the plume would be mostly comprised of inert noble gasses which would dissipate and do not pose a contamination hazard.
  • Radiation doses to the public would likely be very low and would not exceed the Generic Criteria thresholds for default protective actions as outlined in the PNERP Annex E

The review of nuclear emergency planning in Ontario has driven improvements to the Provincial Nuclear Emergency Response plan (PNERP) which enhanced the Province’s ability to address severe (but highly unlikely) accidents like the Fukushima accident.

The most likely ways in which people may be exposed to radiation by:[19]

  • External Contamination: The contamination of the skin and/or clothing with radioactive particles or materials
  • Internal Contamination: The inhalation of radioactive material or the ingestion of materials into the body
  • Direct Exposure: Exposure to the source of the radiation either internally or externally. An example would be receiving a chest x-ray.

There are many potential mitigation actions available to protect the public and emergency workers from the effects of a radioactive emission or dose. These include specific protective actions, precautionary measures, exposure control, and ingestion control measures designed. Authorities usually implement such measures before a radioactive release has begun, but may do so post-release. Which measures are used depends on the type of radioactive material, the amount released, the size of the affected area, land use and the population.

Precautionary measures include:

  • Closing of beaches, recreation areas, etc.
  • closing of workplaces and schools
  • suspension of admissions of non-critical patients in hospitals
  • entry control restricting access to the affected area to essential personnel
  • clearing the milk storage of dairy farms
  • banning consumption of any item of food or water that may have been exposed outdoors
  • banning consumption and export of locally produced milk, meat, produce, milk-and meat-producing animals
  • removing milk- and meat-producing animals from outside pasture and exposed water sources

Exposure control measures include:

  • Evacuation
  • Temporary relocation
  • Iodine Thyroid Blocking; involves the ingestion of Potassium Iodide (KI) to block radioactive iodine from entering the thyroid.
  • Sheltering-in-Place – Remaining indoors, with windows and doors closed and external ventilation systems turned off.
  • Ingestion control measures include:
  • Restricting the consumption, sale, or trade of potentially contaminated milk or water Restricting livestock and other food animals from grazing on potentially contaminated pastures
  • Restricting the consumption, harvest, sale or trade of potentially contaminated produce and crops
  • Restricting the movement, grazing areas, sale, trade OR slaughter of potentially contaminated livestock

Possible triggers of a nuclear emergency include:

  • A Loss-of-coolant accident (LOCA) with fuel failures on one or more reactor units
  • A fuelling machine accident
  • A spent fuel bay accident
  • A loss of all AC power at the reactor facility
  • Extreme environmental conditions
  • Earthquake damage
  • Explosion/Fire
  • Intentional attack, negligence, human-error or other human factors

During a nuclear emergency, the release of radioactive isotopes such as iodine, cesium and strontium is possible. There is no ‘anti-radiation’ cure; however, potassium iodide pills block the binding of radioactive iodine in the thyroid and reduce the risk of the development of radioiodine-induce thyroid cancer. Potassium iodide, however, does not provide protection from any other radioactive isotope or material that is released during a nuclear emergency. The Canadian Nuclear Safety Commission (CNSC) requires the distribution of Potassium Iodide (KI) to households that fall within the 10 km Detailed Planning Zone. Residents that live within the 50 km Ingestion Planning Zone are able to acquire KI from local pre-distribution points such as pharmacies.[20]

There have been over 17,000 cumulative reactor-years of commercial nuclear power operation in 33 countries[21]. Ontario has utilized nuclear power since the 1970’s.[22] Reactor facilities currently provide more than half of the province’s electricity[23].

Spatial Scale

Spatial Scale: A nuclear emergency resulting in an off-site release of radioactive material has the potential to affect a wide area although the extent of the impact may vary significantly depending on accident severity.

Timing: There is no particular time at which this hazard is more likely to occur.

Warning: The Provincial Nuclear Emergency Response Plan and designated municipality emergency response plans are in place to help warn the public of a nuclear emergency and in advance of any planned radioactive releases.

Potential Impacts

Depending on the severity of plant damage and integrity of containment systems, intermittent radioactive emissions to the environment could continue for weeks and could affect a relatively small or large area around the reactor facility.

The potential impacts of a nuclear emergency could include:

  • Disruption or closure of government, business or financial institutions.
  • Enactment of milk, water, and foodstuff consumption bans
  • Risk to public health, including contamination through the environment, potable water, food, animal products and other vectors.
  • Illness or death. May strain the health system and response resources.
  • Illness or death of domestic or livestock animals.
  • Ecosystem damage or disruption. Need for assurance monitoring of the environment.
  • Psychosocial effects including stress disorders
  • Worker shortages and business continuity issues.
  • Reputational Damage.
  • Long-term population health monitoring.
  • The need for case and contact management, such as isolation and quarantine.
  • The need for evacuation or shelter in place.
  • The need for site or area access restrictions.
  • The need for emergency provision of essential needs, including food.
  • The need for increased public safety or policing measures.

Secondary Hazards

Secondary hazards associated with a nuclear emergency may include:

  • Civil Disorder
  • Electrical Energy Failure
  • Fire/Explosion
  • Food Contamination
  • Geopolitical Pressures
  • Road and Highway
  • Water Quality

Past Incidents

There have been three major nuclear emergencies in the history of civil nuclear power generation - Three Mile Island, Chernobyl and Fukushima.

  • Three Mile Island, 1979: Although there were no detectable health effects on plant workers or the public, the Three Mile Island accident in Dauphin County, Pennsylvania was the most significant accident in U.S. commercial nuclear power plant history. Its aftermath brought about sweeping changes involving emergency response planning and many other areas of nuclear power plant operations. It also caused the National Research Council of Canada to tighten and heighten its regulatory oversight[24].
  • Chernobyl, 1986: Chernobyl was a catastrophic nuclear accident that included an explosion and intense fire without provision for containment. 237 people suffered from acute radiation sickness (ARS), of whom 31 died within the first three months. The environmental, human, social and political consequences were severe and continue to this day.
  • Fukushima, 2011: An earthquake, and resultant tsunami disabled the emergency generators used to power the pumps necessary to cool the reactors. The incident caused a breach in containment, allowing the release of radioactivity. The incident displaced over 156,000 people and caused widespread contamination of water, food and air in the surrounding regions[25]. Since this incident, many international jurisdictions including Canada and the United States have published extensive studies and reviewed their nuclear emergency management programs within the context of a severe accident scenario.

Provincial Risk Statement

A severe accident is extremely unlikely due to the types of containment systems used in Ontario. Planning for this hazard is extensive.

Human Impacts

The impact of a nuclear emergency depends on the level of radiation released. A nuclear emergency involving the release of large amounts of radiation could lead to significant doses to the population surrounding the nuclear facility. This could increase the risk of the development of cancer in this population, but it is unlikely that any doses would be significant enough to cause acute radiation syndrome.

Past nuclear emergencies including Three Mile Island and Chernobyl demonstrate the significance of psychological stress as a major health impact[26]. Studies in the wake of the Fukashima disaster also show that those who believe that radiation exposure is likely to cause health effects were significantly more likely to be psychologically distressed[27].

In an actual or perceived threat, it is possible that people could self-evacuate regardless of the actual risk or prescribed direction. Misinformation about the likelihood of such an event and the lack of awareness regarding advances in safety and technology are also significant concerns from a public information and awareness perspective.

Social Impacts

Evacuation and shelter-in-place orders are likely protective actions in response to a nuclear incident. Some societal impacts would result from such orders, or from the psychological effects of such an incident. Large numbers of people may be required to evacuate, with the possibility of permanent resettlement if the radioactive dose rates are high enough.

Property Damage

There may be areas deemed uninhabitable for long periods in the event of a very severe accident.

Critical Infrastructure Disruptions

Critical infrastructure disruptions are possible following a nuclear emergency. For example, roads may be closed to prevent access to impacted areas. In addition, there may be issues related to accessing contaminated critical infrastructure following a release of radioactive material from a nuclear facility.

Electrical power generation capacity could be limited in the event that a generating station becomes damaged or contaminated. Other electrical generating options may not be able to make up for loss of output.

It is possible that cellular networks could become quickly overwhelmed with the volume of traffic in response to an incident, which could also lead to widespread failures of the network.

Environmental Damage

Environmental impacts would be highly dependent on variables such as the extent of a release, should one occur. A nuclear emergency may result in the need for long-term remediation and ingestion control measures may be required for significant periods. Disposal of contaminated waste is of particular concern.


Negative effects on businesses are possible, particularly due to labour disruption issues, power supply issues and other secondary impacts of a nuclear emergency. A significant event would also result in a substantial economic loss to the province, including the possibility of agricultural loses or closing of national borders.

Oil or Natural Gas Release

Go to previous hazard: Nuclear Emergency

Go to next hazard: Radiological Emergency


The uncontrolled release of oil, natural gas, or both.

The release could be from a pipeline or distribution system, vehicles, a well, a storage facility, or a combination of these.[28]


Oil and natural gas are natural resources created from carbon and hydrogen molecules transformed during the long-term decay of organic matter over millions of years, within geological formations[29].

Many different geologic formations contain oil and natural gas deposits. Natural gas is extracted from the ground through wells. Oil sands deposits can be extracted using steam assisted gravity drainage, or through mining activities. While Ontario does have some natural reserves of oil and natural gas, over 99% of Ontario’s oil and natural gas requirements are imported.

Under the Environmental Protection Act, it is the duty of the owner or controller of a spilled pollutant to clean up a spill. They must do everything practicable to prevent and eliminate the negative effects from a spill, including restore the natural environment to its original state.[30]

Oil and natural gas have many uses. Below are some commonly used petroleum gas products.: 

  • Oil: gasoline, diesel fuel, synthetic rubber and fibres, plastic, pesticides
  • Natural gas: refers to primarily methane and other gas types such as ethane, propane, butane, pentanes and heavier hydrocarbons Used for heating (water heating), plastics, fertilizers.
    • Natural gas is converted into Compressed Natural Gas (CNG) or Liquefied Natural Gas(LNG).
    • Propane, or Liquefied Petroleum Gas (LPG), is used in rural areas and communities without access to natural gas.

Oil or liquid petroleum consists of a mixture of liquid hydrocarbons. The viscosity of oil can range from being as thin as water to as thick as tar. It is referred to as ‘crude oil’ if it has not been refined.[31]

Natural gas does not naturally have an odour, so distributors add mercaptan to give it a distinct smell, though this often occurs only after delivery. This increases the chances of detection, and can help to minimize the risk of a natural gas emergency. This is usually done once it reaches its destination municipality.[32]

Some of the hazards associated specifically with natural gas are:

  • Asphyxiation: Natural Gas dissipates in large, open areas. In enclosed spaces, Natural Gas can displace air. Even though it is non-toxic, a person can be asphyxiated from a lack of air.
  • Fire: natural gas can ignite if it is present in small concentrations.
  • Explosion: if natural gas is present in small concentrations and in an enclosed space with a source of ignition, it may result in an explosion
  • Hydrogen Sulphide: hydrogen sulphide may exist as an impurity within reservoirs of natural gas. Hydrogen sulphide is very toxic to humans.

Hazards associated with storage or distribution of oil or natural gas could include:

  • Spills or releases: The rupture of part of the system could result in the release of its contents, which may be under high pressure. Oil spills can result in significant damage to the environment and are difficult to clean.[33] Releases of gas are far more difficult to detect and contain, as they are colourless and in most cases odourless until they reach a municipality for sale.
  • Blast Effects: The pressure of the system contents could result in projectiles (pieces of the pipeline itself) thrown into the air at high speeds. Liquid pipelines generally do not suffer blast effects when ruptured.
  • Fire and Explosion: oil fires in oil wells, pipeline or storage facilities can be extremely difficult to extinguish due to the abundance of fuel. The pressure and contents of filled storage tanks would increase the risk of an explosion. The smoke produced by these fires may contain chemicals and particulates that are harmful to human health without proper safety precautions. In the vast majority of accidents, ignition does not occur.
  • Noise: The release of natural gas under high pressures is very loud and can result in hearing loss and disorientation in people close to the ruptured section.


Many methods of distributing oil and oil products such as gasoline and diesel for storage and retail. Trucks are the main distribution system for petroleum at the retail level, which adds risk factors for road and highway hazards and transportation infrastructure.

Much of the transmission pipeline infrastructure in Ontario located in remote areas. Pipelines are typically used to move crude oil from the wellhead to gathering and processing facilities.

Ontario has over 200,000 kms of pipelines, including 2,390 km of crude oil and oil products pipelines, 12,450 kms of natural gas transmission (large diameter/high volume), and 189,000 kms of natural gas distribution pipelines.[34] Pipeline systems are very complex, ranging from small distribution lines customers, to large transmission lines that use high pressures to move product over long distances through large-diameter pipes.

All pipelines are regulated and adhere to Canadian Standards Association (CSA) standards. These standards are enforced in Ontario by the Technical Standards and Safety Authority (TSSA). The risk of a pipeline emergency is further reduced through federal and provincial requirements that utilities that own/operate pipelines must conduct inspections in order to detect leaks and pipeline corrosion before they result in an emergency situation.


Natural gas is stored in order to meet the expected peak demand in the colder months for heating. Natural gas is stored in underground pinnacle reefs and similar geological formations, in order to minimize the risk of an explosion or a release affecting the public - it is never stored on site. Ontario’s liquid natural gas storage sites are located at Dawn in southwestern Ontario, principally under land used for agricultural purposes such as crop farming.[35]

Improperly maintained wells, including abandoned or improperly capped wells, may pose a threat. It can also be dangerous for activities such as construction to occur in the immediate vicinity of an unknown well.

Crude oil and refined product storage (other than at retail gas stations) is usually above ground. Oil storage hubs contain crude oil or unrefined product, while product terminals store refined product. Product terminals are more widely distributed than refineries and are generally located near major markets.

Spatial Scale, Timing and Warning Period

Spatial Scale: The spatial scale of an oil/natural gas emergency depends on factors such as the amount of oil/natural gas.

Timing: Oil/Natural Gas Emergencies can occur at any time of the year.

Warning: Warning varies depending on the situation.

Potential Impacts

Potential impacts of an oil/natural gas emergency may include:

  • The need for evacuation or shelter in place.
  • Enactment of milk, water, and foodstuff consumption bans
  • Risk to public health, including contamination through the environment, potable water, food, animal products and other vectors.
  • Illness or death. May strain the health system and response resources.
  • Ecosystem damage or disruption. Need for assurance monitoring of the environment.
  • Reputational damage.
  • The need for evacuation or shelter in place.
  • The need for site or area access restrictions.

Secondary Hazards

Secondary hazards may include:

  • Fire/Explosion
  • Geopolitical Pressures
  • Petroleum Product Shortage
  • Water Quality

Past Incidents

As it is mandatory to report spills and releases, there are copious examples of oil and natural gas releases. Some prominent examples are included below.

  • Gogama, 2015: Several tanker cars caught fire after a Canadian National Railway train carrying crude oil derailed in northern Ontario. Some of the rail cars that caught fire entered the Mattagami River System. Officials advised nearby residents to stay indoors and avoid consuming water from local sources.
  • Windsor, 1993: A leaking fuel line connected to a storage tank released 4500 litres of fuel oil to the storm sewer system.
  • North York, 1979: A gasoline escaped from a separator and entered the sewer system underneath the industrial area near Finch and Sheppard. Estimates of gasoline that entered Dufferin Creek vary between 800 and 2,000 gallons.

Provincial Risk Statement

Oil and natural gas systems, facilities and assets cross and are located in a variety of populated areas. Risk factors include location of the rupture, local population density, environmental sensitivity, and many other factors.

Human Impacts

One of the most dangerous occurrences at a well is a blowout, which may not initially ignite. However, during the initial blowout, serious injury and death can occur to workers on site. There is also the risk of product escaping from a storage, distribution or other site, which could be dangerous to those who encounter it.

Social Impacts

Social impacts such as evacuations, significant disruption of transportation, or other critical infrastructure are possible. Such effects are not common, and are usually limited to a local area.

Property Damage

Localized damage possible, particularly to property associated with oil and gas storage or distribution. Any failure of the storage or distribution infrastructure is likely to also affect the surrounding area and property.

Critical Infrastructure Disruptions

A large event may result in a disruption in the supply and distribution resulting in an fuel supply emergency.

Environmental Damage

Perhaps the greatest risk is environmental contamination. This may pose a risk to ground water. In particular, failure of oil infrastructure or accident in transport may result in severe environmental damage, requiring long-term remediation.


The impact on businesses may vary depending on the magnitude of the event. Most events are likely to affect the business responsible for storage or distribution. However, a significant loss at a major supplier may affect additional businesses by triggering fuel supply issues or shortage.

Radiological Emergency

Go to previous hazard: Oil or Natural Gas Release


An emergency caused by ionizing radiation, released by a source other than a reactor facility.[36]


A radiological emergency may occur through the intentional or accidental release of ionizing radiation. The threat of contact with radiation could be real or perceived. Intentional attack and sabotage involving radioactive materials are not included in this profile.

As unstable atoms decay, they release radiation. Radiation can be one of two types:

  • Non-ionizing radiation, including microwaves and radio waves: Non-ionizing radiation has only enough energy to excite electrons.
  • Ionizing radiation, including X-rays and gamma-rays: Some forms of radiation can remove electrons from, or ‘ionize', other atoms as they pass through matter[37]. Both the newly freed electron and the atom that lost the electron (now an ‘ion’) are able to cause damage through interactions with other molecules.

Ionizing radiation could come from small research reactors, particle accelerators, or other locations. The Canadian Nuclear Safety Commission does not consider these sites ‘reactor facilities’ due to their small size, though they are licenced.

Uncontrolled exposure of radioactive material could result in health effects. The International Atomic Energy Agency considers a radioactive material ‘uncontrolled’ if it is unshielded (taken out of its’ protective covering), abandoned, lost, stolen or otherwise outside of regulatory control. These are also known as ‘orphan’ sources.[38]

Radiological emergencies may also arise from misuse or faulty industrial and medical sources, space objects (satellites), or from accidents involving the transportation of radioactive materials. While radiological incidents may occur from time to time these are often small and mitigated quickly without any negative effects.

As radiological incidents are rare, there may be incidents where first responders are not familiar with the hazard or aware that it is the cause of the emergency. Radiation cannot be seen, smelled, felt or tasted, and requires specific detection equipment to alert users to its’ presence.

Ionizing radiation can cause two types of health effects:[39]

  • Deterministic Effects: Radiation-induced, acute health effects include changes to cells and tissues. The main acute health effect is acute radiation syndrome (ARS). This illness can lead to symptoms such as weakness, hair loss, vomiting, damage to the organs and skin burns. If the dose of radiation received from exposure is high enough, acute radiation syndrome can be lethal.[40]
  • Stochastic Effects: Chronic exposure to radiation at lower doses and over a long period (years) can cause effects such as cancer and heritable diseases. The energy level of the radioactive material is not enough to cause immediate health effects (such as cell death). Negative health effects may not appear until months or years after exposure. [41]

Exposure of people or animals to radiation could occur in several different ways:

  • Direct exposure (being near a source of radiation)
  • External Contamination (radioactive particles or material that contaminate the body, skin or clothing)
  • Internal Contamination (introduction of radioactive particles or materials inside the body through inhalation, ingestion or adsorption)

Exposure severity depends on:[42]

  • Features of the radiation emitted: Different types of ionizing radiation cause different damage to cells and tissues. Different radioactive isotopes can affect the same tissue differently.
  • How exposure occurred: direct exposure, external contamination or internal contamination.
  • Amount of time spent near the radiation source: exposure is greater if time spent near the source is greater.
  • Proximity to the radiation source: exposure increases the closer you are to the source.
  • Presence and type of shielding: The type of shielding, which ranges from a piece of paper to a lead-lined wall.

Spatial Scale, Timing and Warning Period

Spatial Scale: The scale of the emergency depends on the source of the radiological exposure (e.g., dose rates and types of radiation being emitted).

Timing: There is no particular season in which radiological emergencies are more likely.

Warning Period: The timing of initial warnings from the Province may depend somewhat on the timeliness of initial reporting by emergency responders or others. As radiation needs specialised equipment to detect, there is the potential for a radioactive hazard to exist for some time before someone notices.[43] Plans are in place to warn the public of a radiological emergency.

Potential Impacts

Potential impacts of a radiological emergency may include:

  • Risk to public health, including contamination through the environment, potable water, food, animal products and other vectors.
  • Illness possible. May strain health system and response services.
  • The need for site or area access restrictions.
  • Long-term population health monitoring.
  • Ecosystem damage or disruption. Need for assurance monitoring of the environment.
  • Reputational damage.
  • The need for evacuation or shelter in place.

Secondary Hazards

Secondary hazards may include:

  • Food Contamination
  • Geopolitical Pressures
  • Water Quality

Past Incidents

There are no prominent examples of radiological incident in Ontario.

Provincial Risk Statement

There are thousands of radiation sources in Ontario, found in research facilities, universities, industry and medical buildings. Many of shipments travel through populated areas and along busy highways. Though uncontrolled exposure to ironizing radiation is rare, extensive mitigation and preparedness measures are in place to reduce and prevent risk.

Human Impacts

Health effects may not appear for days, weeks or even years depending on the length, type of radioactive material and form of exposure.

Radiation is impossible to detect without special instrumentation and skills and exposure may not manifest itself immediately.

The psychological effects, particularly given that this is a potentially significant but invisible hazard, could be equally if not more prevalent than their physical health consequences.

Social impacts

Studies of radiological accidents have found that for every contaminated individual, there may be over 500 concerned people.[44] Fear, concern and anxiety, as well as protective directions leading to social isolation or fragmentation of communities, could create real and perceived threats to community social support networks and support systems.

Property Damage

A radiological emergency could contaminate property and commodities, rending them unusable for a considerable time. Property damage may be permanent.

Critical Infrastructure Disruptions

The need for specialized decontamination and healthcare in the event of a radiological incident would put additional stress on the healthcare system, including from widespread public anxiety about the health effects of radiation. Stress on infrastructure could occur as a direct effect of contamination within the safety perimeter, or as a secondary effect of resource availability.

Environmental Damage

Radiological emergencies can include a risk of ground contamination including contamination of food and water supplies. If contamination or exposure levels exceed Operational Intervention Levels (OIL) as outlined in the PNERP, exposure control or ingestion control measures may be warranted. Depending on the level of contamination, temporary or permanent relocation of residents, as well as environmental decontamination, may be necessary. Some areas of Ontario have historic contamination from non-emergency events that can provide an indication of the level of cleanup that could be required following a radiological emergency[45].


Radiological emergencies may result in business and financial impacts to businesses residing within or adjacent to the affected area, with secondary and cascading affects proportional to the size and effects of the release. It is possible that the entire Province would be affected through economic, social or reputational loss, including but not limited to border closures.

End Notes

[1]Ministry of Ministry of Energy, Northern Development and Mines, 2018. . Correspondence [via email] June 2018.

[2] Chemistry Industry Association of Canada, 2017. Chemistry Industry Economic Profile 2017.

[3]Environment Canada 2017. Water – The Transporter. Accessed September 2018.

[4]Invest in Ontario, 2018. Chemical and Biochemical Industries. Accessed June 2018.

[5] Government of Canada, 2016. Risk management of Chemical Substances. Accessed June 2018.

[6] Government of Ontario, 2018. Guideline for Implementing Environmental Penalties (Ontario Regulations 222/07 and 223/07). Accessed June 2018.

[7] Ministry of the Environment, Conservation and Parks, 2018. Correspondence [via email] June 2018.

[8] National Pollutant Release Inventory, 2018. Accessed July 2018.

[9] 2016 Emergency Response Guidebook, 2016. Accessed July 2018.

[10]Transport Canada, 2017. Annual Statistics. Accessed May 2018.

[11]The Canadian Disaster Database, 2018. Accessed June 2018.

[12] National Pollutant Release Inventory 2018.

[13] Definition from the Ontario Provincial Nuclear Emergency Response Plan (PNERP) Master Plan 2017.

[14] Definition from the Ontario Provincial Nuclear Emergency Response Plan (PNERP) Master Plan 2017.

[15]Office of the Fire marshal and Emergency Management, 2018. Correspondence [via email] march 2018.

[16] Ontario Power Generation. 2017.

[17] Ontario Power Generation. 2017.

[18] Canadian Nuclear Safety Commission, 2018.

[19]International Atomic Energy Agency (IAEA) 2018. Accessed November 2018.

[20]Canadian Nuclear Safety Commission, 2018. Potassium iodide (KI) pills Accessed November 2018.

[21] Safety of Nuclear Power Reactors, World Nuclear Association, 2016.


[23] Ministry of Energy and Infrastructure, 2015

[24] US Nuclear Regulatory Commission, February 2013.

[25] World Health Organization, 2012

[26] Canadian Guidelines for Intervention during a Nuclear Emergency.

[27] Psychological distress and the perception of radiation risks: the Fukushima health management survey. World Health Organization 93 (9) Sept 2015.

[28]Ministry of Energy, Northern Development and Mines, 2018. [via email] August 2018.

[29] Canadian Association of Petroleum Producers (CAPP), 2010

[30]Ministry of Environment, Conservation and Parks, 2018.

[31] National Library of Medicine, 2010

[32]Ministry of Energy, Northern Development and Mines, 2018. [via email] October 2018.

[33] Transport Canada, 2008

[34] Ministry of Energy, Northern Development and Mines, 2018.

[35] National Energy Board (NEB) 2018. Market Snapshot: Where does Canada store natural gas? Accessed September 2018.

[36]Office of the Fire Marshal and Emergency Management, 2018.

[37] Government of Canada, 2012.

[38] IAEA, 2011.

[39] Canadian Nuclear Safety Commission, 2018. Nuclear and Radiation Glossary. Accessed June 2018.

[40] Ministry of Health and Long Term Care, 2014. Radiation Health Response plan.

[41] Health Canada, 2012.

[42] Canadian Nuclear Safety Commission, 2015.

[43] Strong radioactive source released - Goiâni. IAEA 2008.

[44] Medical Service Corps, Military Medical Operations Department, Armed Forces Radiobiology Research Institute, Bethesda, Maryland 20889, USA.

[45] Canadian Nuclear Safety Commission, 2018.