Bicycle helmets are tested to absorb the force of a simple fall from 2 meters on a flat surface and from a 1.2 meter drop onto a jagged surface. That's an approximate equivalent speed of a 12 and 9 mph impact.

A higher standard does exist. You can find that standard in a motorcycle helmet.

One of the leading experts in the field wrote a paper for England CTC on the topic that you may find worth reading

http://www.cyclehelmets.org/papers/c2023.pdf