Derbyshire Constabulary said people living within 100m of Belvoir Crescent in Newhall had been moved to temporary accommodation.
Supt Paul Markham said the substance was discovered at a flat during a search of the premises.
A 55-year-old man has been arrested.
Mr Markham said: "We are not looking for anyone else in connection with this matter and we are hoping that people will not be inconvenienced for too long.
"The evacuation is purely a precaution to ensure everybody's safety and residents will be allowed back home as soon as possible."
More than 200 residents have been evacuated from homes in south Derbyshire after the discovery of what police called a "potentially volatile substance" in a flat.