The international standard ISO 14040 (ISO, 2006) requires that the goal of an LCA study shall unambiguously state the intended application, the reasons for carrying out the study, the intended audience and whether the results will be used in comparative assertions intended to be disclosed to the public.
The goal of this study was to assess the potential life cycle environmental impacts associated with the production, use and end-of-life management options for individual types of mercury-containing lamps in New Zealand. This information will be used to interpret, for the purpose of informing product stewardship policy, the potential environmental impact of the different lamps, the different end-of-life management options in the context of the performance and applications of the lamps appraised.
The original scope of work as defined by the Ministry for the Environment was to focus on the end-of-life management options in the context of the performance and applications of the lamps appraised. In particular, this included an assessment of the relative Life cycle impacts of mercury-containing lamps when managed under the following product stewardship scenarios:
- recycling at end-of-life;
- disposal in landfill at end-of-life; and
- reducing mercury at source.
Although not part of the original scope for the LCA in the MfE objectives for the study, the LCA study as undertaken allows consideration of the implications of greater energy efficiency of the lamps in the use phase, as well as implications of changes in lamp lifetime.
The study assesses separately six typical types of lamps, as listed below:
- Linear fluorescent lamp (LFL);
- Compact fluorescent lamp: external ballast (CFLe); and
- Compact fluorescent lamp: integral ballast (CFLi).
- High Intensity Discharge (HID):
- High pressure sodium (HPS);
- Metal Halide (MH); and
- Mercury Vapour (MV).
The lamps listed above represent the mainstream types used in New Zealand for residential, commercial and industrial applications. This study has not considered lamps that are integrated into other products, such as, those contained in fridges, LCD screens and projectors. Some of these lamps types are known to contain mercury; however, they are outside the scope of this study.
The primary focus of the study is to assess the whole life environmental impacts from the use of the mercury-containing lamps above, and the trade-offs that arise from potential product stewardship options for end-of-life management (by increasing recycling/ recovery rates) and for lamp design (by reducing the lamps mercury content). Additionally, use phase energy consumption and lamp lifetime are considered.
The product stewardship scenarios that have been assessed include the following:
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 level1 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 above listed scenarios will be compared against the Baseline scenario of 9% recovery and recycling at end-of-life.
The study does not to provide comparative results across the different lamp types. This is because the lamps offer a different function and performance characteristics relating to lamp lifetime, lamp output (in terms of wattage) and in terms of lamp application (although application may be the same in many cases for CFLe and CFLi lamps). As such the lamps are not functionally the same and should not be directly compared. Each lamp may be assessed within each lamp type for the different scenarios assessed. Refer to Table 2 for specific details.
The results indicate baseline performance and comparative product stewardship options by individual lamp type for typical usage for New Zealand in 2007.
The study and subsequent results are intended to be communicated for internal and external use to inform the MfE of the development of a product stewardship scheme for lighting in New Zealand. The MfE is anticipated to use the study to support external communication relating to product stewardship of lamps.
Additionally, it should be noted that issues beyond those relating to environmental impacts of a product stewardship scheme, for example, relating to the wider context of regulation, implementation, economics and issues of practicability (e.g. consumer engagement) are outside of the scope of this study.
1. It should be noted that the technical requirements for establishing mercury levels in the lamp will vary according to several parameters, for example, production technology and associated potential improvements, as well as the technical requirements for lamp design which affect, for example, light quality and lamp lifespan.