Community Health Center of New Britain on Washington Street in New Britain was evacuated as a precaution after a chemical spill in an exam room just before 10:30 a.m.
The chemical, formocresol, is a commonly used in dentistry, officials said.
The state Department of Energy and Environmental Protection responded to ensure the spill is cleaned properly.
Everyone will be allowed back into the building once the spill is cleaned.
No one reported feeling ill.