Most of the food bought in the supermarket is sold in packages. To protect the interest of the consumers these pre-packages need to express the quantity, volume and/or mass of the product that is sold. In general, the volume needs to be indicated for liquid products and for all other products there needs to be an indication of the product´s mass or number. For example, on pre-packed meat the number of grams is indicated and milk has an indication in litres. This way the consumer knows how much he is buying for a certain price.
Where liquids require an indication of the volume when sold in pre-packaging, this is not the optimal indicator. For consumer protection reasons an expression of the mass is better.
First of all, measurement instrumentation used for mass is under legal control such as mandatory periodic reverifications whilst the instrumentation used for length, volume and number is not. This legal control provides more guarantees the measuring instrument functions correctly.
Moreover, selling on mass is to be preferred as each molecule has its own mass. This avoids misunderstandings caused by aeration of the product, influences of changes in temperature and, where partially gasses are involved, pressure. Additionally, weighing equipment is more accurate than measuring equipment for volume.
For the reasons above CECIP believes that expressions of mass on pre-packaging are better than expressions of volume.
CECIP is convinced that to provide the most reliable, accurate and realistic indication of the product an expression of mass should be included on the pre-package. By doing this the consumer is better informed about the product he or she is buying. However, this doesn´t mean the volume indication needs to be removed as that it is still possible to express the volume next to the mass.
To improve consumer protection, changes to Directive 76/211/EEC, OIML Recommendation 79 and WELMEC guides are necessary. Therefore, CECIP calls on all relevant stakeholders such as the European Commission and national authorities to improve the consumer protection and request expression of mass on all pre-packages.
The full position paper can be found here.