Hazards Based On Energy Sources

I came across this interesting diagram in an office today. It shows 8 energy sources which may lead to a hazard. (Motion, Chemical, Radiation, Electrical, Gravity, Heat/Cold, Biological, Pressure)
It is amazing to see that all the sources of hazards we can think of can be covered by only 8 categories. I made few unsuccessful attempts to think of a hazard which doesn’t fit in these categories :)

This is a simple and powerful diagram.