Discharge lamps, like most other types of lamp, have a ﬁnite life. Whether a discharge lamp has reached the end of its ‘rated life’1, the end of its ‘economic life’2, or is to be replaced for an LED lighting system, will require care in their safe disposal.
The aim of this article is to consider the issues surrounding the safe disposal of discharge lamps and the control gear associated with discharge luminaires. Additionally, information on environmental aspects and, in particular, the Waste Electrical and Electronic Equipment (WEEE) Directive will be discussed.
Discharge lamps are those which produce light by generating an electric discharge in a gas. Examples of such lamps are shown in Fig 1.
Similarly, the electrical and electronic control gear associated with luminaires will generally fail and/or require replacement at some time during their life.
When a discharge lamp has ceased to function or has reached the end of its effective life, great care should be taken when disposing of it. In addition to the hazards associated with broken glass, some of the substances within a discharge lamp are classed as hazardous to health.
For example, a broken ﬂuorescent tube will release mercury contaminated with beryllium, which can have a detrimental effect on human health. Furthermore, whilst the amount of beryllium and mercury in a single discharge lamp may be small, disposing of large quantities of lamps may have a signiﬁcant effect on the environment.
Similarly, low-pressure sodium vapour lamps (SOX) and high-pressure sodium vapour (SON) lamps contain sodium and mercury, which are both classiﬁed as substances hazardous to health. Sodium requires careful handling during the disposal process, as there is normally sufficient sodium in a typical SOX lamp to ignite should it come into contact with moisture, including the sweat on a person’s hand.
Waste containing substances such as sodium, mercury or lead (in solder), as found in discharge lamps and their associated control gear in luminaires, is classiﬁed as ‘hazardous waste’ under the Hazardous Waste (England and Wales) Regulations 2005 and the Hazardous Waste Regulations (Northern Ireland) 2005, and as ‘special waste’ under the Special Waste Amendment (Scotland) Regulations 2004.
The hazardous waste or special waste classiﬁcation (as applicable), and the introduction of the WEEE Directive, amongst other things, encourages end users to recycle their hazardous waste or special waste rather than send it to a landﬁll site.
End users, other than those in private households, choosing to continue disposing their hazardous waste or special waste (as applicable) by landﬁll, may ﬁnd that this choice becomes a more expensive option as the number of landﬁll sites licensed to accept such waste becomes fewer, and the costs associated with disposing of hazardous waste or special waste in this manner increases. End users in dwellings are not charged for disposing of their hazardous or special waste.
There are many reasons why discharge lamps and their associated control gear should be recycled, including:
- reduction of the health and safety risks to persons,
- reduction in the amount of mercury sent to landﬁll sites,
- promotion of an environmentally friendly image, and
- demonstration of environmental best
practice, which can assist with ISO14001³ accreditation.
Further information on recycling and disposing of hazardous waste or special waste can be found by visiting the Department for the Environment, Food and Rural Affairs (England and Wales) website www.defra.gov.uk or the Scottish Environment Protection Agency website www.sepa.org.uk, as appropriate.
In 2003, the European Union (EU) adopted the Waste Electrical and Electronic Equipment (WEEE) Directive to deal with the end-of-life problems associated with disposing of electrical and electronic equipment. The Directive seeks to improve the way we manage waste, electrical and electronic equipment and encourages and sets criteria for the collection, treatment, recycling and recovery of such waste.
Under the Directive, producers of WEEE that is not from private households must set up systems for its recovery and transport to authorised treatment facilities. Electrical installers will inevitably be in this category, at least from time to time, and should have such a system in place. Additionally, the Directive sets proposed targets for rates of recovery, recycling and reuse of various types of WEEE.
Users of electrical and electronic equipment in private households must have access t the necessary information to:
- ensure WEEE is not mixed with other types of unsorted waste
- ensure separate collection
- understand the collection and return systems
- understand their role in waste recovery
- recognise the effect of WEEE on the environment
- understand the meaning of the symbol which must appear on the packaging of WEEE (a crossed-out wheelie bin, see Fig 2).
¹ Rated life is generally considered to be the physical failure of the lamp
² Economic life refers to the hours of operation during which a lamp is designed to provide optimum light output and colour quality, and economic energy consumption. The economic life of lamps is generally 60% to 70% of the lamp rated life.
³ ISO 14001 is the International Standard for Environmental Management Systems. Accreditation to ISO 14001 can demonstrate commitment to the environment and promote a ‘green’ corporate image.