Fire companies from Montgomery and Delaware Counties extinguished a blaze involving chemicals yesterday at Fine Grinding Corp. in Conshohocken.

An employee discovered the fire shortly before 7:15 a.m. Firefighters initially were concerned about chemical products in the building, said Conshohocken Fire Marshal Joe Januzelli, who did not know know what the chemicals were. Five homes were evacuated as a precaution, and the residents were able to return to their homes by late afternoon, he said.

There were no injuries, Januzelli said. He said runoff water from the fire was being monitored, and there was no sign of any contamination flowing into the nearby Schuylkill.

According to the company's Web site, it specializes in blending, screening and grinding materials into particles from one inch to submicron size.

- Mari A. Schaefer