The real costs of crushing
When disposing of used light sources, building operators have the choice of crushing them before they are removed from site, or employing a contractor that will take away intact lamps for processing.
Following the implementation of numerous pieces of legislation, and with the WEEE Directive coming into force, it is now totally unacceptable to send used discharge lamps (fluorescent, metal halide, sodium etc) to landfill. As a result, any buildings that use these lamps – and that’s virtually all commercial and industrial buildings – have to ensure they are disposed of responsibly. Which means they must be broken down to their constituent components, with as many components as possible being sent for recycling.
Essentially, there are two ways of going about this. The lamps can be crushed on site – or they can be taken away whole to recycling premises specifically designed for the job, so that all of the processing is carried out in one place.
In this respect, there is a common misconception that crushing on site reduces the volume of material that has to be transported, so environmental impact through transportation is reduced. In fact, when you look at this in more detail, this is simply not the case.
On-site lamp crushers tend to be relatively primitive compared to the sophisticated machines used by specialist recyclers. Consequently, the resultant crushed lamps comprise quite large glass fragments which do not rest uniformly in the collection vessel; so the overall volume reduction is typically only 33%.
In addition, these crushed lamps still have to be taken to a designated plant for further processing. As most crushing companies have not invested in the expensive distillation equipment required, nor the associated PPC permit that is required to facilitate mercury recovery on their sites, further transportation to a third site is also necessary. Which means that all three sites involved in this chain have the potential for mercury contamination.
In addition, building operators need to consider the extra Duty of Care that falls on them when they undertake crushing on site. Considerations include Health & Safety procedures relating to the handling of glass, plus the risk assessments and COSHH regulations relating to the processing of mercury-bearing hazardous waste on their own site. In addition, employees may be subject to regular surveillance to ensure they have not been exposed to mercury and the same may be true of the site itself, as well as nearby water courses.
The alternative approach, using an accredited lamp recycler, eliminates many of these concerns. While the lamps are on site they are stored in specially designed, secure containers bearing all the necessary signage. Thus, there is minimum danger of contamination or non-compliance with legislation. They are then transported in purpose-designed vehicles to ensure that transportation is efficient and safe.
On arrival at the contractor’s facility, the lamps are processed on a single site so that risk of contamination is minimised. The lamps are processed in machines that contain all mercury vapour and glass as the lamps implode, and deal safely with any flammable hydrogen gas and sodium that are released at the same time.
Phosphors are then stripped from the glass so the glass can be recycled, while the phosphors are separately collected within the process and then processed in a purpose designed distiller at temperatures (around 800°C) which enable liquid mercury to be reclaimed as a virtually pure liquid. Sodium is also reclaimed and any ferrous and non-ferrous metals are also separated and sent for re-use.
All of these activities take place within the strict safety regime demanded by the Environment Agency before they will issue a PPC Permit.
Discharge lamps are among the most difficult types of waste to deal with because they are made up of so many different materials. For this reason, the decision on how best to deal with them is not one to be taken lightly.
To that end, it’s important to consider all of the costs – not just the obvious ones. Extra risk assessments and health and safety procedures may be absorbed into other budgets but they are still real costs to the organisation. In addition, there is greater peace of mind in outsourcing specialist operations to organisations that are geared up for them and fully accredited. They take the risk and building operators have the satisfaction of knowing they have discharged their duties responsibly.