Actually... it would be more like a cloud of vapor, spreading from the impact area along with various debris.
Im not sure about the issue though, since it was reduced quite a lot from the previous effects these surfaces had in the beta.
Also, ive noticed that if you walk slowly, step by step - you get much less damage then if you accidentally try to run.
Which seems reasonable to me. After all if you are standing in fire and make a step - you will get burned more, because you just stepped onto a burning surface again. Similar with poison-acid kind of a surface.
