Rounding guidelines are one of the factors that influence the determination of tolerance limits, including the number of significant digits, or decimal places. The purpose of these guidelines is to prevent false levels of precision and thus to define specific ways of determining nutritional data provided to customers on food packaging.

This is easiest to understand in practice.

Rounding nutritional values.

Example: a protein value given on the packaging as 12 g may represent a protein value in the product of between 11.5 g and 12.4 g. This is only due to the application of typical rounding, i.e. from 0.5 we round up to a full 1, and rounding down to a full 1 results from results greater than 1 up to 1.4.

Such a result and the same rounding rules apply to values ​​resulting from calculations made using a nutritional calculation program or laboratory analysis.

Another issue, and it is important not to confuse these concepts, are tolerance limits. We emphasize once again, because it is extremely important, that "tolerance limits" and "rounding rules" are two different matters.

Tolerance limits for nutritional values.
To illustrate this, we will continue using the same example, in which it was that the value for protein given on the packaging as 12 g, may represent the value of this protein in the product of between 11.5 g and 12.4 g. However, in the situation of checking these values ​​in the finished product, in the event of values ​​​​less than 11.5 and greater than 12.4 being shown during the test, giving the result 12 on the packaging may still be accepted by the inspectors as correct if... this result falls within the tolerance limits for this ingredient.

Specifically, referring to the example - for protein, the tolerance specified by the implementing provisions of the Regulation is ±20%. What does this mean in practice?

In practice, this means that this gives a tolerance limit for the upper range calculated as follows:
- 12.4 g plus 20% gives a result of 14.88 g, rounded to 15 g,
- 11.5 g minus 20% gives a result of 9.2 g, rounded to 9 g.

The conclusion from this is that tolerance margins should be applied to the upper and lower limits of values ​​that can be rounded for labeling, in the event of differences revealed during the inspection. In the case in question, if the analysis shows a content of between 9-15 g, then such a result should be considered to be within the tolerance limit.

However, in order for the inspection result not to be negative, i.e. not to result in sanctions for the manufacturer, it is necessary to have correct documentation that will factually indicate the nutritional values ​​from which the rounding was made and will allow inspectors to refer if it is necessary to take into account tolerance limits.

More about tolerance limits in the article: Tolerance limits of the nutritional value of products.

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