Why does ADR require a shovel, drain seal and plastic collecting container for many loads bearing labels 3, 4.1, 4.3, 8 or 9?

1. So the driver can bury leaking packages in a field and continue the journey
2. So spilled product can be contained, drains blocked, and residue collected instead of polluting soil or water
3. They replace fire extinguishers on vehicles over 7.5 tonnes
4. They are required only for Class 1 explosives, which are in the basic module