Demand for cullet from both the glassmaking industry and aggregates businesses has grown over the past few years with new glass processing plants opening and alternative markets developing.

Thanks to Defra funding and the need to hit recycling targets,  many local authorities are now expanding their glass kerbside collections. These are increasing the amount of cullet in the marketplace, but the material collected is often mixed glass, rather than the colour sorted material provided by bring banks.

UK glass manufacturers prize clear glass most highly because while most glass made in the UK is clear, by far the largest proportion of the glass waste stream is green. For this reason green is prized the least. Completely mixed glass cannot be used in the container re-melt industry, where colour purity is vital, but must go to alternative uses. This has led to controversy within the industry over the usefulness of mixed collections. However, as glassmakers are starting to use colour sorting equipment, colour contamination of separately collected colours is becoming less of a problem.

The amount of glass recycled to make new containers hit record levels in 2005. According to British Glass, 742,000 tonnes of used cullet was made into new containers in this country in 2005, an increase of 67,000 tonnes (just over 10%) on the previous year.

Despite increasing competition from alternative glass markets such as aggregates, rising energy costs and limits on carbon emissions are leading container manufacturers to do everything in their power to use more recycled cullet. But although many glassmakers would argue container manufacture is the best use of cullet, as glass can be re-melted countless times, as tonnages of collected glass grow, alternative uses such as grit blasting, use in road surfaces and water filtration will become increasingly important in ensuring end-markets. In 2005, about 280,000 tonnes of recycled glass went into alternative markets.

Another, relatively new end market for waste glass is the export market, now becoming an important factor in boosting recycling rates. According to Defra figures, 242,890 tonnes of glass packaging was exported for recycling in 2005, taking the total amount of UK glass bottles and jars recycled up to about 1.26 million tonnes in that year.