I know the ISO Standard doesn’t specify anything about that but we don’t want to buy a shredder and afterwards the shredder doesn’t fulfill the requirements of the ISO standard. Maybe you as an expert can share some experience with us.
Commercial shredders are normally classified in security levels that can range from a low-security P-1 up to a maximum-security P-7, the higher the value, the smaller the pieces produced.
P-4 shredder is the minimum security level for sensitive information, while a high security shredder is either a Micro-Cut (P-5), Super Micro-Cut (P-6), or a High Security-Cut shredder (P-7). P-6 and P-7 are most used by security firms and government agencies.
So, you have to evaluate which types of information you will use on the shredder to define the proper specification.