|BWMA - campaigning for inch-pound industries and
Metric Transport and Signs
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Metric: the Death of
In the days prior to
pre-packed foods, most foods were sold "loose from bulk". This had the effect
of protecting consumers from short measure, since they needed to specify
quantities to traders prior to purchase, such as asking for a "pound of
sausages". A trader providing less than the requested amount would be charged
with serving short measure and subject to legal penalties.
Nowadays, most foods are sold
in packs with the result that customers do not specify quantities; they merely
pick items from shelves. As a result, producers who reduce quantities are not
committing an offence since no agreement existed between the seller and buyer
as to the exact quantity required.
If consumer protection from
reduced measure is to be maintained, it follows that packaged foods and goods
must be marked in weights and measures that are readily understandable by the
shopping public. In this way, shoppers can spot any reduction in measure.
The experience of metric
demonstrates that it does not provide understandable information. This is owing
largely to the abstract nature of metric units:
- Metrication results in huge
numbers on food packaging (185g, 375g, 425g, 440g, etc). This vast increase
in the size of numbers occurs because metric units are much smaller than
customary units; 28 grams to one ounce, over 450 grams to one pound, 568
millilitres to one pint, and so on.
- Metric units are derived from the
geometry of the earth and have no frame of reference relating to food.
This means that the number of grams or millilitres needed to represent a
product is necessarily arbitrary, unlike traditional units that revolve around
quantities typically dealt with.
The above factors have contributed to a
general failure of metric units to find common acceptance by British people for
food and drink packaging. Technically, metric indicates quantity as accurately
as the customary system, but it fails to convey meaning or value. Whereas six
ounces of cheese actually sounds like a quantity of cheese, 180g of cheese is
just a very large number.
- Metric fails to produce consistent
or easily understood sizing scales. Unlike the 16oz pound that is geared to
multiples of two, the kilogram cannot comfortably accommodate successive
halving. Thus, while some metric packaging builds up as 100g, 200g, 400g, etc,
this will not integrate with one kilogram meaning that other packaging
progresses as 125g, 250g, 500g, etc. Other packaging uses 75g, 150g, 300g, etc
while others still use 110g, 220g, 330g, 440g. A large variety of packaged
foods has no identifiable sizing scale at all, for example, tomato ketchup and
Thus, while supporters of the metric
system extol its "simplicity" and "rational internal relationships", metric's
streamlining exists only on paper; as soon as it is applied to the physical
world that relies on divisions of 2, 3 and 4, metric indications turn into
archaic three-digit numbers that lack the logical size intervals that exist
under the UK system. Metric was adopted on the basis of its supposed
simplicity, yet one of its main effects is make descriptions more complicated.