The role of LCA methods in assessing the sustainability of flame retardants and their use Gary Stevens and Amy Mitchell GnoSys Global, University of Surrey, Guildford, UK
Materials KTN Meeting on Fire Retardant Materials: Safety vs Sustainability, Bolton, 6 October 2011
Outline •
Sustainability and the role of Life Cycle Analysis
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FR and nanomaterials parallels
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Conventional and un‐conventional LCA tools
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Case studies – SP study on Fire‐LCA of TVs and upholstered furniture – PU Europe study on FR aromatic polyester polyols – TSB funded project on sustainable FRs for filling pad materials
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Observations on FR substitution and alternatives
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Some general observations
Sustainability and the Role of LCA
Risk
Environment
Risk
Sustainable Development
Society
Economy
Risk
Conventional LCA Does Not Address Concerns on, and Perception of, Chemical Risk of FRs •
European concerns on environmental impact, fate and toxicity of certain flame retardants
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REACH, RoHS, hazard/risk phrases, Ecolabels, EPDs, ........
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Concerns: Persistence, Bioaccumulation, Toxicity (PBT) – in ecosystems
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Indoor air quality: FR volatile and particulate emissions
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Occupational exposure: primary production, compounding and recycling
Perspective on FR and Nano Materials •
Environmental concerns over the potential risks that halogenated and some organophosphorous chemicals pose have been a reality for decades – linked to persistence, bioaccumulation and toxicity (carcinogenic, mutagenicity, ... etc) associated with certain halogenated organic compounds and their combustion products
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Similar concerns regarding nanomaterials and particularly nano particulates are more recent – some FRs also come under this category
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In response to these concerns, non‐halogenated alternative FRs have been promoted and developed as alternatives /substitutes and some polymeric Br‐FRs developed to breach the gap – Some examples include phosphorous based FRs, Al(OH)3, Mg(OH)2, borons, siloxanes, etc – More recently development has moved to nano‐additives, such as naturally occurring smectite clays, such as montmorillonite and combinations of two or more complimentary systems – Nano‐additives have an added benefit of improving materials physical properties as well as lending fire retardance to the product
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Alternative approaches to product design and materials selection to avoid the use of additives are being considered ‐ including green chemistry approaches
References: G C Stevens, A Emsley, B. Kandola, R Horrocks et al; Defra report (2011) on “Fire Retardant Technologies: safe products with optimised environmental hazard and risk performance”
LCA across the supply chain: societal benefits versus risks Nanomaterials and FRs share similar LC issues
Extraction and processing
Manufacture of Nanomaterial
Distribution / Transport
Manufacture of Nanoproduct
Distribution / Transport
Nano Zinc Oxide (http://www.nanozinc.co.za/laboratory‐results.html)
Adapted from “The potential benefits of nanotechnologies should be assessed in terms of life cycle assessment (LCA)”, UK Royal Society (2004), Nanoscience and nanotechnologies: opportunities and uncertainties
Use
End of Life
Life Cycle Assessment Improvement assessment
Goal definition & scoping
Impact assessment
Inventory
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First : define the “goal and scope” of the problem – this sets the boundary condition – can be selective provided important impacts are not transferred – allocation is also important
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Then: carry out an life cycle inventory (LCI) analysis of the impacts to be assessed. Following assessment of the impacts, ways to improve (usually reduce) the impacts are assessed.
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The process is iterative and is constantly refined to achieve the most representative model possible
LCA of Nanotechnologies and FRs •
Very few LCA studies of nanomaterials and FRs have been undertaken which meet the full scope of an LCA as defined in ISO standards
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Where studies have been carried out the benefits and disbenefits/risks have not been fully addressed: for example .... – A study of nanocomposite use in automotive applications examined the benefits of these materials over metal components – weight saving, which translates to fuel savings, lower CO2 and economic savings for the consumer – An economic study carried out in tandem suggested that the manufacturing costs to produce nano‐composite body parts would be higher than metallic ones – This study acknowledged additional factors important, such as maintaining safety performance, cost and other desired attributes – trade‐offs not examined – Similar incompleteness in FR alternative and substitution studies e.g. BrFRs – technical, economic, environmental impact, hazard, risk and life saving benefits not sufficiently studied – trade‐offs only poorly examined
References: Karn, B., Aguar, P., (2007) Nanotechnology and Life Cycle Assessment, Synthesis of Results Obtained at a Workshop Washington, DC 2–3 October 2006. Lloyd, S. M. and Lave, L. B., (2003) Life Cycle Economic and Environmental Implications of Using Nanocomposites in Automobiles, Environ. Sci. Technol., 37, 3458‐3466. Jeffrey W. Gilman, National Institute of Standards and Technology (2008), “Sustainable Flame Retardant Nanocomposites” G C Stevens, A Emsley, B. Kandola, R Horrocks et al; Defra report (2011) on “Fire Retardant Technologies: safe products with optimised environmental hazard and risk performance”
Product Life‐Cycle Impacts Feedstock
Monomers/Polymer
Polymer Formulation
Finished Product
FIRE Transformation
Polymer Component
Consumer Use EOL
Incineration Recycling
Early Disposal
Landfill
FR Product Life‐Cycle Environmental Impacts FR Feedstock
FIRE Transformation VOCs smoke/soot inhalation skin contact
FR Manufacture
Polymer Formulation
Finished Product
Polymer Component skin contact ingestion particle/gas inhalation
Consumer Use EOL
Incineration Recycling
Early Disposal
Landfill
VOCs skin contact particle inhalation
Atmospheric, Terrestrial and Aquatic Environmental Impacts
Tools to assess life cycle environmental impacts, economics social performance and fire impact • Environmental Life cycle assessment (LCI and LCA) models – environmental impact assessment e.g. SIMAPRO, GaBi, TEAM , EIME, ...
• Holistic LCA (hLSA) – simple economics and environmental impacts ‐
SimaPro‐
extension, CHAMP (includes cascade use) ‐ GnoSys
• Fire LCA – SP/IVL model – includes account of fire impacts – no economics • Social LCA (sLCA) –
social metrics to assess societal benefits ‐ developing
• Life Cycle Costing (LCC) – also called Total Cost Assessment (TCA), includes all direct, indirect costs and contingent liabilities, risks and uncertainty – e.g. cable fires in tunnels ‐ GnoSys
• Large Project Spatial LCA – LEETS ‐ includes sLCA ‐ GnoSys • Product application LCA – dedicated bespoke models and tools
LCA of flame retardant products SP and IVL of Sweden have undertaken Fire‐LCA assessment of flame retardant containing TVs and upholstered furniture: – These assessments include data collected from their own experimental work on emissions resulting from accidental fires of these products and the influence of the FR on these emissions – The assessments also include statistical and historic data gathered on the incidents of accidental fire in these products to assess the societal benefits of human lives saved and injuries averted – The studies tend to focus on a comparison of non‐FR and FR products – where the FR is a conventional non‐halogenated FR – End of life and accidental fire event impacts were the focus of the investigations; manufacture and raw materials were included in the studies and the FR was found to have a negligible impact on the overall life cycle environmental impacts
Reference: Petra Andersson and Margaret Simonson, SP Håkan Stripple, IVL, SP Swedish National Testing and Research Institute, “Fire safety of upholstered furniture, A Life Cycle Assessment – Summary Report
SP‐IVL Fire LCA model
Development of the Fire‐ LCA model. P Andersson, M Simonson, et al. 2003
Reference: “Fire‐LCA Guidelines”, Petra Andersson, Mararet Simonson, Claes Tulli, Hakan Stripple, Jan Olov Sundqvist, Tuomas Paloposki, Norden, Nordic Innovation Centre (2005)
Fire LCA case studies • TV sets: – Modern TV sets represent a significant fire load and can be the initial cause of fires, through internal faults or dust accumulation – TV related fire statistics were used in this study to assess the full life cycle including emissions in accidental fires
• Upholstered furniture – Fire statistics were used to assess the changes in the number and extent of fires resulting from a move to fire resistant furniture • The UK introduced in 1988 Furniture Fire Safety Regulations – not adopted in Europe – The pollutant emissions from accidental fires, of different severity, involving FR and non‐FR furniture were obtained using full scale fire tests – Two different FR systems were examined • A phosphorous based flame retardant • A bromine based flame retardant
Reference: “Product Life Cycle impacts of flame retardant use” European Flame Retardants Association, Cefic (2006) “Fire safety of upholstered furniture, A Life‐Cycle Assessment – Summary Ropert”, Petra Andersson and Margaret Simonson, SP Hakan Stripple, IVL
Fire‐LCA study of TV sets •
The FR TV sets showed higher HBr emissions due to the FR system
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The FR TV set showed considerably lower total emissions of both PAH and dioxins/furans ‐ identified as cancer risk emissions
Reference: “Product Life Cycle impacts of flame retardant use” European Flame Retardants Association, Cefic (2006)
Fire‐LCA of Upholstered Furniture ‐ Sofas •
For Sofas the non‐FR product was responsible for significant HCN and PAH emissions
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PCDD/PBDD dioxin emissions were higher for FR sofas – The PAH emissions using risk weighting were deemed to be of higher importance
Reference: “Product Life Cycle impacts of flame retardant use” European Flame Retardants Association, Cefic (2006)
Whole Life Emissions of PAH of non‐FR and FR sofas including accidental fire
Reference: “Product Life Cycle impacts of flame retardant use” European Flame Retardants Association, Cefic (2006)
Eco‐Profile of Aromatic Polyester Polyols (APP) Allocation of impacts for the FR component •
A study has been undertaken (sponsored by PU Europe) to create an European average cradle‐to‐gate Life Cycle Inventory (Eco‐profile) of Aromatic Polyester Polyols in compliance with Plastics Europe Eco‐Profile Guidelines
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Primary data was collected from four APP producers for use in this assessment
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APPs are important intermediate products for many production chains, such as polyisocyanurates and polyurethane rigid insulation foams
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Production of APP can be done in different ways and using different raw materials – It involves a number of additives and functionality enhancers
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After esterification, FRs are added to the APP – The study examines the impacts of producing the material both with and without the FR – The FR is unspecified due to confidentiality
Reference: “Eco‐Profile of Aromatic Polyester Polyols (APP), Sponsored by PU Europe, PE International
APP system Esterification process for the production of APPs
Reference: “Eco‐Profile of Aromatic Polyester Polyols (APP), Sponsored by PU Europe, PE International
Comparison of APP production with and without FR FU = production of 1kg of APP Impact Category
APP with FR
APP without FR
Difference
Abiotic Depletion Potential (kg Sb eq.)
0.03
0.03
0
Global Warming Potential (kg CO2 eq.)
2.77
2.58
0.19
Acidification Potential (kg SO2 eq.)
6.16 e‐03
5.79 e‐03
3.7 e‐04
Eutrophication Potential (kg PO4‐3 eq.)
1.09 e‐03
1.02 e‐03
7.0 e‐05
Ozone Depletion Potential (kg R11 eq.)
9.96 e‐08
8.91 e‐08
1.05 e‐08
Photochemical Ozone Creation Potential (kg C2H2 eq.)
1.96 e‐03
1.93 e‐03
3.0 e‐05
Primary Energy Demand (fossil) (gross cal. value) (MJ)
74.97
72.14
2.83
Primary Energy Demand (renewable) (gross cal. value) (MJ)
2.06
2.01
0.05
Primary Energy Demand (total) (gross cal. value) (MJ)
77.03
74.15
2.88
Water use (total) (kg)
124
109
15
Reference: GnoSys analysis of PU Europe data
LCA Assessments Including Chemical Risk and Industrial Implementation
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ENFIRO project (European Commission funded): Life cycle assessment of environment‐compatible flame retardants: (with prototypical case studies) – Three FR‐product combinations selected and studied for environmental and toxicological risks, and for viability of industrial implementation. All information will be used for a risk assessment. – The outcome of the LCA and risks assessments will, together with socio‐ economic information be used in a more complete life cycle assessment – A practical approach is followed in which the alternative FRs are evaluated regarding their flame retardant properties, their influence on the function of the products once incorporated and their environmental and toxicological properties – Reports expected in 2012
http://www.enfiro.eu/
ENFIRO approach to study FR substitution options
Reference: “Life Cycle and Risk Assessment of Environment‐Compatible Flame Retardants (Prototypical Case Study): ENFIRO”, Pim E.G. Leonards, Sicco Bransma, Jacob de Boer
Reducing Emissions by Development of Novel Sustainable Flame Retardant Products TSB Reference: TP/7/ZEE/6/S/N0092L
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Work focused on finding a solution to diminishing supplies of recycled wool available for secondary uses in textile pads – The wool finds application in various filling materials as a natural and intrinsic flame retardant ‐ typically present at ~30% by weight – Recycled wool comes from mostly discarded textiles , such as clothing. Synthetic fibres are becoming more desirable than wool and so the availability of wool in second hand clothing is diminishing.
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The work sought to identify “sustainable” FR alternatives both novel and commercially available and assess both their fire and environmental performance using a “cradle to gate” life cycle assessment
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The work was also conscious that any alternatives needed to also be economically viable as price increases per product unit would severely impact on the ability of new products to compete in the market place.
Reducing Emissions by Development of Novel Sustainable Flame Retardant Products •
Three fire retardants were selected from a variety of several “eco‐friendly” available products – The FRs examined all made claims towards being green or sustainable – Several FRs eliminated due to poor FR performance, cost, and practicality in application, and availability
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Chosen candidates contained multiple compounds that were not represented in any of the available materials and LCA databases (SimaPro/EcoInvent was used): impact estimates were made based on the production of individual components, with required raw materials, and process energy
System boundary Collection and of the raw materials (recycled textiles) Transport
Raw material extraction
Normal production processes
Transport
Production of FR
Transport
Treatment with FR
Normal production processes Product finishing and packaging
Waste material
Transport
Disposal to landfill
Contribution of the FR to overall impacts, cradle‐to‐gate
Additional impacts, generated by use of a chemical FR (material impacts) and its application, are shown on the graph with a bold outline
Contribution of the FR to overall impacts (up to product factory gate) •
The graph shows the contribution of each input into producing the FT treated product from cradle to factory gate
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The other material inputs consist mostly of recycled materials and so the impact is relatively low – Because of this the environmental impact of the product is dominated by the energy use and the impacts associated with producing the chemical FR – If the chemical FR was not required, and recycled wool was available, the total life cycle impacts would be lower
Comparison of Benchmark product against product treated with a conventional FR and the three “eco friendly FRs”
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The comparison shows the benchmark case having the lowest environmental impact over all impact categories ─ This is because all of the material inputs in this case are recycled materials, including the wool which acts as the FR
A comparison of benchmark case (using recycled wool), use of a conventional chemical FR, relative to use of virgin wool
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In the virgin wool case 30% by weight of the product is virgin wool as opposed to recycled wool – In this case all of the impacts associated with producing virgin wool are allocated to the product
Sensitivity Analysis: Varying FR treatment level of sustainable FRs
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These results confirm that using increasing treatment levels of Eco‐FR2 increases the environmental impacts such that it no longer appears as competitive from an environment standpoint as Eco‐FR1 – The efficiency of the FR may allow for lower treatment levels
Conclusions •
The benchmark case, using a recycled wool as the FR component has the lowest impact, in all other cases a chemical FR is used and applied using additional process steps, so unsurprisingly has a higher environmental impact
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On consideration of the impact of the chemical FRs, the conventional FR (ammonium phosphate salt), does appear to have a high environmental impact in many of the impact categories used, relative to the other systems studied
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Eco‐FR1 also has a high impact and in some of the impact categories this is greater than the conventional FR – So, although the FR systems are marketed as “green” or “sustainable” options, they may not be performing significantly better than conventional FRs for equivalent fire performance of the product – Other factors relating to hazard, risk and economics will be decisive
Observations on Assessment of Potential FR Alternatives and Substitutes •
Assess “equivalence” of FR polymer material and product technical performance – fire performance , processing, physical properties, durability, etc.
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Assess improvement in environmental hazard and risk performance across the whole life cycle including recycling
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Consider and assess opportunities for net risk reduction across the life cycle including fire incident impacts
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Consider and assess population risk trade‐offs in regard to life cycles which include fire incidents at levels defined by fire statistics
Additional Observations 1.
There is scope to move towards design‐based and inherent FR material approaches which can avoid the use of chemical FR technologies in some applications. However, adoption of these may not offer the best whole life environmental performance as judged by formal LCA. Wider “sustainability factors” must be considered.
2.
On Br‐FRs: exclusion of brominated FRs is technically possible for most product groups but it is not clear if “equivalence” can be achieved for all products. In the absence of risk assessment, exclusion may be justified for those Br‐FRs that produce unacceptable hazards and where the application of the precautionary principle is appropriate.
3.
The hazard assessment classification of alternative chemical FRs to halogenated FRs should be harmonised and preferably risk assessed, to give potential users confidence in adopting them knowing they are less hazardous than the FRs they replace.
4.
Metrics for “equivalence” are required to evaluate FR substitution options. These should be developed in the context of life cycle sustainability and net risk reduction, and ideally agreed internationally.