The term ?gthe most severe packing group possible for the chosen PSN?h means that if UN 1993 Flammable liquid, n.o.s. sample is chosen as PSN, the most severe PG I must be assigned. Therefore the combination packaging to be used must have an X indication, i.e., the combination packaging must meet PG I performance standards.
The ?gnet weight per package not to exceed 2.5kg?h spelled out in DGR 3.11.3 (d) means that the net quantity per outer package must be within 5kg. Taking UN 1993 Flammable liquid, n.o.s. sample as an example, PG I in PI 351 must be within 1L. If CAO PI 361 is used the maximum net quantity must not exceed 2.5L (assuming specific gravity is 1.0). The maximum permissible quantity for PI 361 is 30L but for transport of samples the net weight is restricted to 2.5kg. There is no disparity.