It built up to wildly unstable levels from the late 1990s, peaking in 2008.

Potassium could build up to dangerous levels in your body.

Mercury can build up to toxic levels in the human body and cause neurological damage.

Positive feedback builds up the input signal to very high levels.

If you have poor kidney function, pentoxifylline can build up to toxic levels in your body.

How could the chemical have built up to such prodigious levels?

This product may contain aluminum, which can infrequently build up to dangerous levels in the body.

The pressure had apparently built up to dangerous levels.

Gases are trapped in the pond under the ice and can build up to toxic levels over winter.

However, ozone can build up to levels that may be hazardous both for grower and plant.