# Directive 1999/2/EC of the European Parliament and of the Council of 22 February 1999 on the approximation of the laws of the Member States concerning foods and food ingredients treated with ionising radiation, Division 1: DOSIMETRY

Extent: E+W+S+N.I.

Overall average absorbed dose
It can be assumed for the purpose of the determination of the wholesomeness of foodstuffs treated with an overall average dose of 10 kGy or less that all radiation chemical effects in that particular dose range are proportional to the dose.
The overall average dose,
D −
, is defined by the following integral over the total volume of the goods:
D − = 1 M ∫ p x,y,z d x,y,z dV
where
M the total mass of the treated sample
p the local density at the point (x,y,z)
d the local absorbed dose at the point (x,y,z)
dV dx dy dz, the infinitesimal volume element which in real cases is represented by the volume fractions.
The overall average absorbed dose can be determined directly for homogenous products or for bulk goods of homogenous apparent density by distributing an adequate number of dosimeters strategically and at random throughout the volume of the goods. From the dose distribution determined in this manner an average can be calculated which is the overall average absorbed dose.
If the shape of the dose distribution curve through the product is well determined, the positions of minimum and maximum dose are known. Measurements of the distribution of dose in these two positions in a series of samples of the product can be used to give an estimate of the overall average dose.
In some cases, the mean value of the average values of the minimum dose (
D − min
) and maximum dose (
D − max
) will be a good estimate of the overall dose: i.e., in these cases:
overall average dose ≈ D − max + D − min 2
The ratio of D − max D − min should not exceed 3.

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Source: https://www.legislation.gov.uk/eudr/1999/2/annex/III/division/1 (the official version)
Page: https://openlegislation.uk/eu-directive-1999-2/annex-III/division-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.