State health officials on Friday removed radioactive materials from a San Carlos home, officials said.

Around 10:30 a.m. Friday, a team from the state Department of Public Health arrived at the home on the 1000 block of Cedar Street, where officials had discovered radioactive materials on Thursday.

Officials did not know how much material was on site, but they said it was contained and did not pose a threat to the public.

Cedar Street was closed between Brittan and Arroyo avenues as authorities worked throughout much of Friday to collect and remove the hazardous matter before disposing of it.

The San Mateo County Environmental Health Services division alerted the Redwood City Fire Department on Thursday that it had discovered the material with low to moderate levels of radioactivity at the unoccupied home.

The radioactive elements discovered were cobalt-57 and radium-286, Fire Chief Stan Maupin said.

“We don’t suspect anything nefarious or bad intent with this material,” Maupin said.

The house belonged to Ronald Seefred, who died in January at age 82.

Seefred worked as a science and engineering technician at the SLAC National Accelerator Laboratory in Menlo Park from 1961 until his retirement in 2003, said Brian Sherin, the lab’s deputy director for operations.

The lab — run by the Department of Energy and Stanford University — conducts research in chemistry, biology and materials science, and astrophysics, and some of this work includes handling radioactive materials, Sherin said. He couldn’t confirm whether cobalt-57 and radium-286 were used during the time Seefred worked at SLAC.

“To our knowledge, none of the materials described came from SLAC,” Sherin said. “We have a very detailed accounting system and all of our materials are accounted for.”

The discovery prompted a two-hour closure of the street Thursday from Brittan to Arroyo avenues, along with nearby Burton Park and the San Carlos Youth Center.

The Sheriff’s Office of Emergency Services and the San Mateo Consolidated Fire Hazmat team also responded to the scene.

Ashley McBride is a San Francisco Chronicle staff writer. Email: ashley.mcbride@sfchronicle.com Twitter: @ashleynmcb