dangerous ground

We filtered the results, focusing on sites that remain dangerous for human exposure and sites that have dangerous ground water.

“We are on dangerous ground here, comrade,” said he in a whisper to Clara.

The adult who substitutes the realities of life by elaborate day dreams is approaching dangerous ground.

She stopped short, as if suddenly realizing she had stumbled upon dangerous ground.

I know I am treading on dangerous ground and venturing to approach very close.

Had they been less confident of their own importance they would have realized that they were treading on dangerous ground.