He is Adrian Martin, 56, of San Jose.
At the time of the explosion, he was preparing a pre-gas mixture involving methane, helium, and nitrogen, said Chief Harold Schapelhouman of the Menlo Park Fire Protection District.
A woman standing near the door of the lab was thrown clear and survived with only some damage to her eardrum.
The scientist preparing the mixture was seriously injured. He was recovered from the lab, but he later suffered cardiac arrest and died at the scene, Chief Schapelhouman said.
Fire officials found a leaking methane cylinder in the lab, although it was not clear if the cylinder was leaking before the explosion or if the leak was caused by the blast.
Firefighters ventilated the building Friday night, allowing the cylinder to dispel all of its contents before starting a secondary search and the investigative process, the fire chief said.
The explosion was contained within the building, located in a business park, said Chief Schapelhouman. There is no danger to the community, he added.
Twenty-three people were evacuated after the explosion, which occurred at about 4 p.m. A woman was taken away in an ambulance.
A county hazardous materials team responded to ensure that the area was safe.
Membrane Technology is involved in the separation of industrial petrochemicals, Chief Schapelhouman said. The company recently received a $3 million federal grant to do carbon-capture research.
-- Almanac staff and Bay City News Service