DOSES

The prevailing minimum dose given is 25 kGy, where Gy stands for Gray= 1 J/g absorbed radiation energy. There is an older unit, rad, where 1 Gy=100rad. 25 kGy is therefore the same as 2.5 Mrad. The standards allow for considerably lower doses, provided that one can prove the killing effect. Monitoring of the bioburden is therefore required. The method is sophisticated and costly and should only be used when the material , e.g. pharmaceuticals, cannot stand the normal 25 kGy.The maximum dose varies and depends on the product, but a rule of the thumb is that it might be double the minimum dose.