For example, some police do not know that cannabis can be legally prescribed. - While it may be theoretically good to arrest people based on how the cannabis affects them individually, rather than by a set standard, it would take a long time to be able to introduce this. Here, there is also no international example, and the UK standard driving limit is already higher than many other countries, if not the highest. - The swab company which provides tests to Police Scotland will not sell to anyone other than Police Scotland.