Disruption Classes are categories of anomalous entities ranked by their possibility to threaten normalcy, possibly upsetting the current status quo of Earth. The classes are ranked by their potential of disruption to the human population.
The known or potential disruption is so low as to not be a concern. The object is essentially inert when not interacted with and may potentially only affect a single individual. The Foundation would find it trivial to clean up after it.
The known or potential disruption would be localized to a small handful of people. The anomalous effects certainly do affect multiple people, but it would not extend very far. The Foundation would find it relatively simple to neutralize its effects.
The known or potential disruption would be extended to a number of people roughly defined as a city. The anomalous effects could spread with fairly significant speed, fast enough as to cause concern. The Foundation would find it moderately difficult to neutralize its effects.
The known disruption would extend to roughly the size of a large metropolitan area to an entire country. The potential disruption could extend to the entire known world. The spread would be swift and difficult to manage. The Foundation would find it quite difficult to neutralize its effects.
This Disruption Class should be reserved for special circumstances when The Foundation is essentially "declaring war" on an anomaly. When an anomaly poses such a dire threat to the status quo and The Foundation's veil that there is no other option than to use all possible options in order to Neutralize it. The effects of an Amida anomaly would extend to the entire known world and possibly the entire universe.