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Executive Summary

Background

The Ministry for the Environment contracted ERM to undertake a life cycle impact assessment (LCA) study of mercury-containing lamps to assess the relative life cycle impacts of mercury-containing lamps when managed under the following scenarios:

  • recycling at end-of-life,
  • disposal in landfill at end-of-life,
  • reducing mercury at-source, and/or
  • some combination of the above.

The purpose of this study was to identify the potential environmental impact (environmental harm) of different types of lamps, and different end-of-life management options (in the context of the performance and applications of the lamps appraised).  The results of this study will inform product stewardship policy.

A Working Group made up of representatives from the Ministry for the Environment, lighting industry, recycling sectors, local government, and lighting retailers has been investigating the potential for developing a product stewardship scheme for lighting products.

The group identified a three-phase approach to developing and implementing a product stewardship programme, as follows:

  • Phase 1:New Zealand Lighting Industry Product Stewardship Scheme – Phase 1 Assessment and Review (completed January 2008).  An external consultant was commissioned to carry out Phase One funded jointly by the Ministry for the Environment and the Working Group. This work included an assessment of the current status of the lighting industry and its environmental impacts in New Zealand. More specifically, market characteristics of the lighting industry, potential harm to the environment and human health from lighting products, industry’s ability to address issues, and a review of potential product stewardship models and best practices. 

The Phase 1 report identified information gaps to be overcome prior to considering further work; a mercury inventory for New Zealand and a life cycle impact assessment of mercury-containing lamps for the lighting sector.

  • Phase 2: The need to understand the relative environmental impact of the mercury from mercury-containing lamps compared to the impact of mercury from other sources (anthropogenic or natural) in New Zealand is covered in the 'Mercury Inventory and Flow Analysis' report (completed May 2009).  This information also helps to inform the development of New Zealand's policy on the reduction of mercury pollution for the proposed UNEP-led international initiative on mercury reduction.
  • Phase 3: This life cycle assessment report represents Phase 3.  This ISO compliant study (completed June 2009) assesses the whole-life environmental impacts of mercury-containing lamps for the New Zealand lighting industry. 

Scope of the LCA Study

The study has been conducted in compliance with international standards for LCA (ISO 14040/44) and has been externally reviewed by an expert panel of peer reviewers.

The study has assessed the whole-life environmental impacts that arise from mercury-containing lamps for New Zealand specific conditions, including overseas raw material manufacture, overseas lamp manufacture, lamp import, lamp distribution, lamp usage, disposal and recycling.  Figure 1 on page 27 shows the generic life cycle of the lamps assessed.

The life cycle assessment study has assessed the environmental impact contributions of the following lamp types over 100,000 hours of operation:

  • Fluorescent:
    1. Linear fluorescent lamp (LFL);
    2. Compact fluorescent lamp: external ballast (CFLe); and
    3. Compact fluorescent lamp: integral ballast (CFLi).
  • High Intensity Discharge (HID):
    1. High pressure sodium (HPS);
    2. Metal Halide (MH); and
    3. Mercury Vapour (MV). 

The lamps listed above represent the mainstream types used in New Zealand for residential, commercial and industrial applications. 

The potential contributions of each system are assessed for the impact categories listed below.  The listed impact categories address a range of environmental issues, and thorough methodologies have been employed for these categories.

  • depletion of abiotic resources;
  • global warming;
  • stratospheric ozone depletion;
  • human toxicity;
  • freshwater and marine aquatic ecotoxicity;
  • terrestrial ecotoxicity;
  • photo-oxidant formation;
  • acidification; and
  • eutrophication.

The adequacy of human and ecotoxicity methods, are in general subject of international scientific discussion due to the need to employ assumptions and estimates regarding fate and exposure. 

The results of the study are not comparable across lamp types, as they are not functionally equivalent, due to differences in lamp life, lamp output and application.  However, the results are comparable within each lamp type for the different scenarios assessed in the study, as listed below.

Scenario 1. 50% recovery and recycling at end-of-life;

Scenario 2. 80% recovery and recycling at end-of-life;

Scenario 3. 100% disposal (to landfill) at end-of-life;

Scenario 4. Reducing mercury level to the technically feasible minimum and 50% recovery and recycling at end-of-life;

Scenario 5. Reducing mercury level to the technically feasible minimum and 80% recovery and recycling at end-of-life; and

Scenario 6. Reducing mercury level to the technically feasible minimum and 100% disposal (to landfill) at end-of-life.

The primary focus of the study has been to assess the whole-life environmental impacts from the use of mercury-containing lamps, and the trade-offs that arise from potential product-stewardship options for end-of-life management (by increasing recovery and recycling rates) and for lamp design (by reducing the lamps mercury content).  In addition, the implications in relation to lamp lifetime and in-use efficiency improvements have also been tested.

Overall Study Conclusions for Mercury-Containing Lamps

The study has assessed and drawn conclusions for the environmental impacts of mercury-containing lamps in two main areas, as follows:

  • Whole life results: which includes the environmental impacts associated with all stages of the lamp life cycle, from overseas raw material extraction through to overseas lamp manufacture, import into New Zealand, distribution, lamp usage, disposal and recycling.
  • End-of-life results: which includes the environmental impacts only associated the end-of-life stages of lamp disposal and recycling.  All other stages are excluded.

Whole Life Conclusions

When considering the whole-life environmental impacts, the results indicate that the use phase dominates the impacts across all impact categories, accounting for more than 90% of the total life cycle.  The manufacturing phase represents around 5% of total impacts and the disposal phase represents around 1% of total impacts across the total life cycle. 

The results demonstrate that an environmental benefit is achieved from increasing the recovery and recycling rates for mercury-containing lamps.  However, in the context of the whole life cycle, the environmental benefits are relatively small. 

In terms of mercury contribution to human toxicity impacts, the results indicate that mercury contributes a low amount to total impacts.  Primarily, the contributions to human toxicity arise from generation of electricity in the use phase, resulting from combustion of gas and coal which releases emissions of PAH and NMVOC to air.  The use phase contributes around 85% to 95% of the total human toxicity impact.  This is the same across all lamp types (with the exception for integrated CFL where the use phase contributes around 65%, due to burdens associated with additional electronics).

When considering other lamp performance parameters, such as lamp lifetime and energy efficiency, it has been demonstrated that significant environmental benefit can be delivered by longer lifetimes and higher efficiencies.  An increase in lamp lifetime reduces production burdens and waste management and results in significant benefits.  Similarly, burdens reduce with reduced energy consumption in the use phase.

Conclusions when only End-of-Life is considered

When considering the end-of-life phase only, the results indicate that increasing recovery and recycling levels of lamps from 9%, in the baseline, up to 80%, then the environmental benefits for the end-of-life phase increase significantly.  The benefits arise primarily from the benefit associated with avoiding the production of new materials that would have otherwise taken place if the lamps were not recycled in other materials. 

In terms of the potential for mercury to contribute to human toxicity impacts, the results indicate that mercury releases from landfill contributes a significant proportion of the potential human toxicity impacts (ranging from around 25% to 90%) from end-of-life .  Increasing the levels of recycling considerably reduces the contribution from mercury disposal at end-of-life. 

When considering the influence other lamp characteristics have on end-of-life, such as lamp lifetime and mercury level in the lamps design, then significant environmental benefit can be achieved by longer lifetimes and reduced mercury-content, as these both deliver reduced quantities of material for disposal/management at end of life. 

For end-of-life product stewardship options, overall, it can be concluded from the results that increasing the levels of recovery and recycling of mercury-containing lamps will provide benefits to the environment. 

Summary of Main Results for Mercury-Containing Lamps

As mentioned above, the summary of results are presented here in two main sections, as follows:

  • Whole life results: which includes the environmental impacts associated with all stages of the lamp life cycle, from overseas raw material extraction through to overseas lamp manufacture, import into New Zealand, distribution, lamp usage, disposal and recycling.
  • End-of-life results: which includes the environmental impacts only associated the end-of-life stages of lamp disposal and recycling.  All other stages are excluded.

Whole Life Impacts: Increased Recycling and Recovery

The results indicate that, for all lamps types, increased recovery and recycling levels reduces the contribution made to the human toxicity and ecotoxicity impact categories.  These benefits are more prominent for domestic lamps (LFL, CFLi and CFLe), ranging from around 2% to 45%, when increasing from 0% to 80% for recycling and recovery.  For industrial lamps the benefits relating to human toxicity and ecotoxicity range from around 2% to 35%, when increasing from 0% to 80% for recycling and recovery.  An example for a compact fluorescent lamp with integral ballast (CFLi) is shown in Figure 5 on page 50.

For all other impact categories, such as global warming potential and resource depletion, the benefits achieved through increased recycling for they are relatively small, in the context of the whole life, due to the significance of the use stage.  The benefits (i.e. reductions in impact) range from around 0% to 3% with increased recycling levels from 0% to 80%.

The primary driver for the reduction in ecotoxicity impacts is due to the environmental benefits that arise from avoided production of mercury material, and the associated emissions of mercury to air from the raw material production process.

The primary driver for the reduction in human toxicity impacts is due to the environmental benefits that arise from avoided production of nickel material, and associated emissions of heavy metals to air (which are non-mercury) from the raw material production process.

Whole Life Results: Reduced Mercury Levels

The study assessed a reduced mercury level of 20% for each lamp.  Overall, the influence of reduced mercury levels of 20% provides an almost negligible reduction in environmental impact compared to typical mercury levels across all impact indicators, with the exception of terrestrial ecotoxicity impacts (as shown in Figure 15 on page 63 for a CFLi lamp), which gives a reduction of around 6% of the impact at an 80% recycling level (and 2% reduction at a rate of 9% recycling and recovery).   

The benefits for terrestrial ecotoxicity impacts are almost entirely driven by the reduced need to manufacture as much mercury for the lamp, associated with reduction in release of mercury to air from raw material manufacturing process.  Also smaller reductions occur at end-of-life landfill disposal which is primarily driven by a reduction in emissions of mercury to soil and to air, which results from reduced levels of mercury entering the landfill.

Whole Life Results: Contribution of Mercury to Human Toxicity Impacts

The contributions of different substance emissions (to air, water and land) that arise in the life cycle for each lamp were assessed for their potential contribution to human toxicity impacts.  The results indicate that mercury emissions contribute under 0.5% of the calculated total potential human toxicity impact for all lamp types. 

The most significant contributing substances relate to poly aromatic hydrocarbons (PAH) to air (contributing generally about 50% of impacts), non-methane volatile organic compounds (NMVOC) to air and other (non-mercury) heavy metals.  These emissions arise primarily from the generation of electricity in the use phase, resulting from combustion of gas and coal.  The results indicate that increased levels of recovery and recycling would reduce total human toxicity impacts and also reduce the levels of mercury release to the environment.  The benefits achieved from changing from 9% to 80% recycling and recovery result in reduction of around 1.5% for human toxicity impacts over the life cycle.

Whole Life Results: Improved Energy Efficiency and Lamp Warm-Up

The study has assessed two areas in relation to lamp operating efficiency in the use phase, as follows:

  • increased energy efficiency of 10% in the use phase (based on a theoretical estimate); and
  • inclusion of reduced energy efficiency from potential warm-up effects (estimated at 0.5% reduction in efficiency).

The results show that for an increase in energy efficiency of 10% the change in environmental impacts across all indicators is significant.  As previously mentioned, the use phase dominates the whole-life impacts, and a 10% reduction in energy consumption has the potential to deliver a similar reduction in impacts.  This is the case for abiotic resource depletion, acidification, eutrophication, global warming potential and human toxicity, which reduce by 8% to 9%.  Other impacts indicators reduce but to a slightly lesser extent (of around 2% to 4%).

The inclusion of warm-up effects would have a negligible influence on all the environmental impact categories appraised, Figure 22 on page 79 shows the results for a CFLi lamp. 

Whole Life Results: Lamp Lifetime

The study has assessed a theoretical scenario of potential implications of extended and reduced lifetime of ± 50% of typical lifetime. 

As would be expected, the environmental impacts reduce with extended lifetime, particularly in relation to human toxicity and ecotoxicity impact categories. This primarily arises due to the reduced requirements for manufacturing the product, as well as reduced waste disposal requirements.  As would be expected, the opposite is true for reduced lifetime.  Figure 21 on page 77 shows the results for a CFLi lamp.

End-of-Life Results: Increased Recycling and Recovery

The study assessed the environmental impacts that arise for increased recycling and recovery levels for the end-of-life stage alone (without considering impacts associated with other life cycle stages, i.e. for overseas raw material manufacture, overseas lamp manufacture, import distribution and usage). 

The results indicate that significant environmental benefits across all impact indicators arise for all lamp types when recovery and recycling levels are increased.  A negative number in the Figure indicates that there is an overall environmental saving. 

These reductions in overall impact are dominated by the environmental benefits that arise through the avoided production of virgin raw materials, as a result of their displacement by materials recovered for further use by the recycling process. 

End-of-Life Results: Reduced Mercury Levels

The study also assessed the potential change in environmental impacts that may arise from reduced mercury levels in the lamp for the end-of-life stage alone (without considering impacts associated with other life cycle stages i.e. for overseas lamp manufacture, import, distribution and usage). 

Table 11 on page 62 shows that the influence of reduced mercury levels of 20% provides an almost negligible reduction in environmental impact compared to typical mercury levels across all impact indicators, with the exception of terrestrial ecotoxicity impacts, which gives a reduction of around 20% of total impact for a recycling and recovery rate of both 9% and 80%.    This reduction results from a direct reduction in emissions from landfill disposal due to a reduced mass of mercury being disposed per lamp. 

End-of-Life Results: Potential Contribution of Mercury to Human Toxicity Impacts

The potential contributions of different substance emissions (to air, water and land) that arise from the life cycle for each lamp were assessed for their contribution to human toxicity impacts. 

When looking at end-of-life only, emissions are accounted for that cause both detrimental impacts, from direct emissions from waste management activities (e.g. heavy metals emissions to air, water and soil), and environmental benefits, through avoided emissions that arise from displaced production of virgin raw materials (recovered for further use by the recycling process).  Negative numbers in the Table reflect the environmental benefits of the avoided emissions. 

The results indicate that increased levels of recovery and recycling reduce total human toxicity impacts that result from mercury emissions from landfill.  However, the primary driver for emissions reductions results from the environmental benefits delivered by avoided production of virgin raw materials.  These avoided emission benefits mainly arise from avoided production of metals (nickel, brass and aluminium) in the lamps.