Can someone please remind me what the 'e' in "500g e" means?

Question

Does it mean the weight is a typical weight that such a product is sold in (e for European standard weight) eg 250g e, whilst for example 291g is not??

Answer 1

The "e" symbol is used by producers, importers or packers to show that their quantity control system works on averages. It can be used for any packing quantity (of weight or volume).

Quoting from Trading Standards' government website:
"The aim of the average weight system is to define acceptable limits of variation to packaging processes, accepting that some packages will be slightly below their stated quantity and others above, whilst ensuring no consumer or trade detriment."

Customers are protected against under-filling because the producer (or importer or packer) has to ensure that every item will pass a Trading Standards Officer's inspection.

To clarify (for chip2001, below):
Producers either pack by minimum quantity (so when you buy a 454g jar of jam, it must contain exactly that amount) or with equipment that packs by average -- it is not always possible to be exact to the gram or millilitre with foods and drinks. So in that case, your jar (let's say it contains whole olives, preserved without oil or brine, as an example of something hard to be absolutely precise about) would be marked 454g e.

In the batch of five jars you mention, the TSO (Trading Standards Officer would expect to find at least 454g as average contents. If all the jars were underweight, the producer would be in big trouble, would face fines, and could have his/her packing plant shut down.
There is a degree of error allowed: if any single jar was less full than that allowable error (Tolerable Negative Error, or TNE) the producer would still be in trouble.
You can find the table for TNEs at the end of the website I have given below.

I'm familiar with it because I'm a beekeeper and I sell honey.
It's just one of the little joys of the Weights and Measures Act 1985.

Here's all the information from the Trading Standards:
http://www.tradingstandards.gov.uk/cgi-bin/bglitem.cgi?file=BADV024-1111.txt

Answer 2

I may be wrong but I thought it was from a European directive that means you can only display the "e" if the contents are guaranteed to be the stated amount; ie, the manufacturer meets the required European standard of weights and measures.
I wouldn't be too happy to know that the weight of my jar of jam or whatever was an "estimated" quantity. If I pay for 454g of jam, I want 454g of jam, not "approximately" 454g of jam.

I feel the reference Phoenix gives is a bit vague - the labelling with an "e" on shows that the producer would pass a check by an inspector. What happens if the inspector picks up 5 jars of jam at random and they're all under the printed weight? Even this official statement uses the word "average" in inverted commas, which I find a bit ambiguous.

Answer 3

the e means estimate. So if you buy a box of cereals weighting 500g for example you will get approximately 500g give or take a few grames