Environmental and quality aspects of lamps have come to the focus of public attention lately mainly because of the Ecodesign regulation on non-directional household lamps and the discussion on the corresponding phase-out of incandescent lamps. Related to this, the interest among consumers as well as experts in new, more energy efficient technologies is increasing. These include, among others, lighting products that are based on light-emitting diodes (LEDs) or organic light-emitting diodes (OLEDs). According to market development forecasts, the market share of LED lighting will increase significantly until the year 2020.
In the present exploratory assessment carried out on behalf of the German Federal Environment Agency, Ökopol analyses environmental and health aspects of lamps based on LEDs and, as far as possible, also of OLED lighting, as well as functional characteristics that are crucial for the acceptance of the technology by end-users.
Based on a description of the composition of the lamps and LEDs and the used substances and materials, the study investigates possible risks related to the used substances, the optical properties, the availability of relevant raw materials, possible recycling scenarios as well as the energy efficiency (development) and further usage characteristics, among them the service life. The focus of the expertise lies on LED lamps that serve as a substitute for the traditionally used incandescent lamps in households, so called retrofit lamps. The results of the investigated aspects are summarised in the following:
Hazardous substances: The substances known to be contained in LED have only limited toxic or ecotoxic impacts according to the available data. A release of these substances from the semiconductor or carrier material is very unlikely under normal conditions of use. A “worst case” estimate (complete release and uptake of substances contained in LED) of possible maximum release levels shows that the resulting exposition for humans and the environment clearly lies below known effect thresholds. However, it is necessary to point out that in the case of missing threshold values an estimation of risks was not possible within this study, especially with regard to the risk to develop cancer in the (unlikely) case of uptake of the substances into the body. In addition, relevant data gaps still exist regarding the substances and characterisation of single compounds. Therefore, it was not possible to provide a full estimation of risks.
Optical properties und assessment related to health aspects: The electromagnetic fields created by LED lamps are, according to measurements, rather low and approximately in the range of those of incandescent lamps considering the known frequency dependent impacts on the human body. High quality LED lamps do already have quite good colour rendering properties. Regarding the share of blue light, a comparison of spectra shows that LEDs do not have a fundamentally different spectral quality compared to fluorescent lamps. The risk of acute blue-light damages caused by white LEDs therefore lies within the range of risks of fluorescent lamps of comparable colour temperatures and can, for the technology currently applied for general lighting, be even lower for children because of the lack of UV components. Increased long-term risks through LED and fluorescent lamps in comparison to incandescent and halogen lamps seem to be in principle possible though due to the higher relative share of blue light. LEDs also often feature high luminances that may cause glare effects, which can, however, be avoided through an appropriate construction of the lamp or luminaire. Independently of the used lighting technology, cold white lamps curb the melantonin synthesis more effectively than warm white lamps at the same illuminance and luminance level because of the higher share of light effective on the circadian rhythm. Whether the impact of warm white LEDs (and fluorescent lamps) on the circadian rhythm is different from that of incandescent and halogen lamps cannot be concluded yet on the basis of the available data.
Availability of raw materials: The greatest supply risk related to raw materials necessary for LEDs exists for gallium, which is currently an essential material as gallium nitride for white LEDs. For gallium, and also for indium it is of particular importance to what extent the raw material efficiency during manufacturing can be improved. In LED phosphors currently mainly yttrium is used, the availability of which should be affected only to a limited extent by an increased LED production. Regarding the electronic components of LED lamps and luminaires, there is no LED-specific raw material problem, as the electronic ballasts are similar to those of other lamps and devices. For the heat sink in LED retrofit lamps relatively large amounts of metals are needed, mainly aluminium, which can affect the price of the lamps. OLEDs, even though they are based on organic semiconductors, require precious materials as well. The availability and costs of these are a decisive factor for the future success of the OLED technology. Generally, they are not competing with LED in this regard, as the used materials are different.
Disposal: It can be assumed that there is no acute risk for humans and the environment when LED lamps get into the currently available disposal paths. Besides the very low share of waste LEDs in these waste streams, the existing risk mitigation strategies of the established disposal methods as well as a reference to the “worst case” scenarios within the preliminary assessment in the chapter on hazardous substances allow for this conclusion. However, if LED-specific types of treatment should be established in the future, an appropriate estimation of risks is necessary and has to be arranged within the processes of permission. However, in view of an increasing amount of waste LEDs to be expected in the medium term, it is to be examined how an optimisation of the recycling process through a more targeted collection and pre-treatment could be established from a resource conservation perspective. Only this way a quantitative return of the contained precious materials into production processes is possible.
Energy efficiency, life cycle and life cycle costs: Regarding the energy efficiency, LED lamps are already slightly more efficient than compact fluorescent lamps. They have a high potential for a further increase in efficiency. LED lamps are already reaching very long life times compared to conventional lamps. Due to these long life times it is, however, difficult to verify whether the luminous flux is maintained over time. Necessary measurements are time consuming so that real experiences with the life time of current products hardly exist. While LED lamps at the moment are still quite expensive compared to other lamps, considerable cost reductions can be expected according to projections. With an increase in energy efficiency, costs for the consumer over the life cycle of the lamp can be expected to be reduced considerably. Available OLED luminaries are currently still very expensive and have a comparatively short service life in conjunction with a rather low energy efficiency. Forecasts, however, see a high potential for improvement in the mentioned functional characteristics of OLEDs.
All in all, the study confirms that so far no serious problems have been “overlooked” regarding the technology path of LED lighting. Regarding particular aspects, further research is needed to decrease the risks and environmental impacts of the expected significant intensification of use of the LED technology. Moreover, it is necessary to guarantee a high quality of lighting products on the basis of LED and OLED.