The life-cycle analysis (LCA) was carried out as part of an official programme to help consumers and retailers to make "environment-friendly" purchases by improving the flow of reliable environmental information to them.
The conclusions of the LCA are expressed in terms of "transition points" - the number of times a porcelain cup and saucer or plate have to be used in order for their environmental impacts to be less than those of polystyrene or paper disposables.
For example, if a porcelain cup is washed every time it is used, it must be used at least 1,800 times before the associated air emissions fall below those of the polystyrene cup (see graph ). But if the porcelain cup is used twice before it is washed, this transition point falls to just 86 drinks.
However, for liquid releases the porcelain cup is always the "unfriendly" choice due to the detergents used in washing. This leaves consumers with the awkward decision on which of the four parameters measured are most important: emissions to air, energy consumption, landfill volumes, or releases to water.
The Dutch LCA was by no means complete. More accurate data are needed on emissions over the complete life-cycle of each product and other effects, such as raw material consumption and litter. Whether recycling of polystyrene cups will have a positive or negative impact on the equation also needs to be determined. The debate on which cups to use is likely to continue for some time.