Tannerite is next to the bottom for explosives. It is not classified as a high explosive. It will take more than a pipe bomb or a pressure cooker to cause maiming unless you are very very close.
ANFO(Oklahoma City) is almost twice as powerful and still not classified as a high explosive.
http://www.usatoday.com/story/news/nation/2016/09/19/tannerite-explosive-bomb/90692338/
Tannerite is essentially ANFO without the fuel oil.
Pretty easy to add the fuel oil. You can look of the percentage needed on the Internets. It is not much.
Powdered Aluminum acts quite a bit like the fuel oil, and that is what is added to Ammonium Nitrate to make tannerite, which is a form of Ammonal. Ammonal is a high explosive.
Tannerite is difficult to get to detonate, it is harder to do than ANFO.
The definition of “high explosive” may have changed since I taught blasting 35 years ago. Then, a high explosive was one that detonated instead of deflagrated. Black powder was considered a “low explosive” because it deflagrates instead of detonating.