The impact of fire on the environment is dependent on a variety of factors and can be difficult to quantify. Ron Alalouff examines research which helps explain the threats it poses and how we can manage them.
Quite apart from its effects on humans, the effluents generated by smoke can have significant impacts on the environment. These include effluents transmitted through the air, by water, or to the terrestrial environment.
The impact on the environment depends on the contents of a building, the materials with which it is built, and the effect of run-off water or other extinguishing agents. One of the most relevant pieces of research on the environmental effects of fire is by the Fire Protection Research Foundation, the research affiliate of the National Fire Protection Association in the United States. The report on the research, The Environmental Impact of Fire, published in 2015, says that in addition to carbon emissions, the impacts of fires on the environment include non-carbon contamination of the air by the fire plume, contamination from firefighting water run-off containing toxic elements, and other discharges or releases from burned materials.
A literature review on the environmental impact of fire considered two main themes: determining how ‘environmental impacts’ from fire are defined to better describe the environmental impacts of concern, and a review of fires with severe environmental impacts. While there is a significant amount of information available on the impact of fires on the environment, it is not complete and there are gaps in knowledge.
There were some limitations on the scope of the study, such as the different ways that ‘environments’ and ‘impacts’ are defined, the types of impact that should be quantified, how they should be quantified, the fact that the types of materials produced during fires depend in large part on what is involved in the fire, and the challenges associated with the range of contents in buildings. These have changed over the years to include more synthetic materials, which are more flammable and toxic than natural materials.
Impacts
The report states that hazards from fires include a wide variety of chemicals and particulates such as general pollutants/indicators, metals, particulates, polycyclic aromatic hydrocarbons (PAHs), chlorinate dioxins and furans, brominated dioxins and furans, polychlorinated biphenyls, and polyfluorinated compounds. But quantifying the impact is difficult, as there are challenges in identifying and appropriately sampling these substances during and after a fire, and exposure time and persistence in the environment can make a difference. These effluents may or may not make an impact on the environment, depending on the exposure time, the means of transmission, and the susceptibility of the receptor (the parts of the environment affected such as air, water, and soil).
The environmental effects from fires can be divided between short-term impacts, occurring over a few hours or days, and longer-term impacts. Short-term impacts relate mostly to the local environment within the fire plume and water run-off zones. Long-term environmental impacts (those not immediately felt or recognised) might be post-wildfire erosion, occurring months, or even years, after the fire has been contained.
Effluent transmission
According to the report, a crucial part of transmission is what is known as the transport medium:
- Airborne fire effluents: The research shows that the emissions of toxic and exotoxic species, inorganic gases, volatile organic compounds, PAHs, and dioxins are often involved in a smoke plume. The main hazard of these gases is the toxicity of the contents and the susceptibility of the receptors.
- Waterborne fire effluents: The impacts on water can be very serious, as fire is commonly extinguished with water or other extinguishing agents. If proper containment and treatment of the run-off are not carried out, water can travel and affect a nearby natural waterway. Many chemicals and potential pollutants are either soluble or can be carried by water to a natural source.
- Fire effluents in the terrestrial environment: The impact on the terrestrial environment is more from long-term exposure, and distribution of effluents to the terrestrial environment can be via a primary pathway, or a secondary pathway where effluents are thrown from the plume down to the ground. The key to identifying the effluents is whether there are any hazardous materials stored on site, as well as any extinguishing agents used.
The United States Department of Energy has developed data that enables the calculation of the embodied energy and CO2 equivalent of different building assemblies. This provides fire departments and other stakeholders with the information needed to calculate the amount of CO2 that is released, based on the area of the materials burned.
Locality
The area affected by the environmental impact of a fire (or fires) should be identified, says the report. Individual buildings can provide the information needed to understand the environmental effects of a fire, and these can be aggregated to calculate the effects regionally, nationally, or globally, depending on the data available.
In the United States, there were 1,240,000 recorded fires resulting in 3,240 civilian deaths and an estimated $11.5bn in property loss in 2013. Data from sources such as the US Census, the National Association of Home Builders, and the Commercial Building Energy Consumption Survey can be used to estimate the numbers and types of buildings. From there, the types of construction materials and building contents can be estimated. Some fires create a local, regional, national, and even international impact, such as the Sandoz chemical warehouse fire in 1986.
The report then goes on to examine environmental policy, which is typically broken down into the different pathways that the environment is exposed to stressors (hazards): air quality, surface water quality, groundwater health, soil health, solid waste management, and food safety.
Ecological effects
An analysis of harm to non-human organisms and ecosystems can be challenging, as it is difficult to determine the effects on animals or plants. Ecological risk analysis requires an understanding of how the affected ecosystem functions. These effects are still being studied, and there is a need to develop appropriate tools for assessing the economic and non-economic value of ecological systems.
The report recommends a number of steps to improve understanding of and information on the environmental effects of fire, including:
- a reporting mechanism for fire services to provide feedback on the risk management of the fire.
- the carrying out of an environmental impact assessment on new buildings in addition to their sustainability certification.
- the exploration of new tools and methods to provide fire services with a clearer idea about which types of intervention would be most beneficial.
- further studies on the effects of building contents in a fire.
- the creation of a database of fire retardants and the products of combustion when they are burned, to better understand their hazard and toxicity.
- more detailed record-keeping of fire events.
Environmental performance tool
A tool that assesses the performance of fire services against the environmental and economic impacts of fire has been developed by the Fire Protection Research Foundation in the US. According to the FPRF, most risk and environmental assessment methods – and many economic assessment methods – require specialised knowledge that is outside the scope of most fire departments. The objective of the environmental and economic assessment tool (EnvEco) is to develop a relatively easy-to-use methodology for estimating the environmental and economic impacts of fires that will help communities understand the degree to which fire department activities influence their environmental and economic wellbeing. The components of the tool are qualitative risk assessments for predicting fire spread to adjacent buildings, a life cycle assessment for estimating the environmental impact of a fire, the fire response and replacement of damaged materials, and a cost-benefit analysis for estimating the economic impact of a fire.
The EnvEco tool uses a spreadsheet platform, on which the user enters data in the input worksheet that is divided into four areas: risk of fire spread, warehouse description, contents description, and fire service response. Default input values based on referenced literature are given when possible. In the early sample form, the tool was developed to be used on a case-by-case basis for warehouse fires in which water was the only suppression medium used. It analyses fire service response to previous warehouse fires in which a defensive strategy was used, and makes a comparison with the predicted consequences of the same fire without fire service response.
The output is the probability of fire spread to adjacent structures, savings in terms of firefighter fatalities and injuries, property damage, job disruption, business interruption, fire service intervention, and rent reduction, and savings in terms of global warming potential, acidification, eutrophication, ozone depletion, smog, ecotoxicity, and energy used.
The full report can be found by searching at https://www.nfpa.org/
Environmental impact of Lithium-ion batteries
Lithium-ion (Li-ion) batteries are responsible for around 48% of all waste fires in the UK, costing waste operators, fire services, and the environment some £158m annually, according to research by the Environmental Services Association (ESA) and Eunomia.
Li-ion batteries are found in an increasing number of electrical and electronic household items such as mobile phones, electric toothbrushes, and even musical greetings cards. These batteries cause a significant fire risk when they get into the residual and mixed recycling waste streams, either loose or inside electrical items. When these batteries are punctured, damaged, or exposed to high temperatures during normal waste processing and sorting operations, they can set fire to dry, flammable waste and recycling around them.
With waste fires burning for long periods – sometimes weeks or months – the environmental damage can be extensive, with harmful greenhouse gas emissions released into the atmosphere and water pollution caused by run-off from extinguishing the fires. Dealing with these fires also means extra work and risk to firefighters, as well as disruption to society through rail, retail, and road closures due to smoke from the fires. Waste site operators must also deal with significant material damage, business interruption, and loss of recycling resources.
Of the 670 fires recorded by ESA waste management members across the UK in 2019–20, 38% were either recorded as caused by Li-ion batteries or ‘suspected’ to have been. This is higher than the percentages recorded in the previous three years (21%, 25%, and 22% from 2016–17 onwards).
The report suggests a number of solutions including banning Li-ion batteries from residual and mixed recycling waste streams, introducing a deposit return scheme for them, and making battery manufacturers pay for the costs of fires their products cause.
“The findings of this research highlight the significant financial burden Li-ion battery waste fires place on the waste sector and public sector services,” said Sophie Crossette, lead author of the report.
“To date, much of the focus on preventing waste fires has been on improved controls and infrastructure at waste sites. As this report suggests, we now need to focus on upstream interventions to divert batteries and WEEE [Waste Electrical and Electronic Equipment] products from the mixed waste stream to tackle this growing issue. If we don’t start to take action now, the increased use of Li-ion batteries will only increase the cost and impact of Li-ion battery waste fires in the years to come.”
The research was supported by the Environment Agency, the National Fire Chiefs Council, and the Waste Industry Safety and Health Forum.
Conclusion
The report concludes that future research to inform decision tools could be beneficial for fire services, building designers, and policymakers. For fire services, steps should be taken to more fully understand the environmental impacts that fire services make when fighting a fire, and what possible changes they can make to reduce their impact. For fire protection designers, there are numerous tools to calculate the environmental footprint of a building and similar techniques could be used to account for the effects of fire. Ways need to be explored to take account of the relative sustainability between different types of fire protection measures, for example, sprinklers versus structural fire protection.
Finally, for policymakers, a decision tool could be developed to holistically understand fire, including the use of fire protection (preventive) and fire intervention (attack). But to achieve this, there needs to be an agreed way of calculating the aggregate effects of a fire, which would need agreement on the relative importance of impacts that affect different parts of the environment. If these can be resolved, an aggregate data set should be produced for comparison to other sources of environmental impacts, and to get an accurate picture of the problem.
Subsequent Fire Protection Research Foundation research on Emission Factors from fires in the built environment can be found here.
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Ron Alalouff is a freelance journalist and editor specialising in the fire safety and security sectors and, more generally, in the built environment.