At about 2:30 a.m., sheriff's deputies patrolling the neighborhood near the 3400 block of Edison Way detected an unusual smell near Edison Technology Park, property owner and manager Ron Newdall said.
The deputies found that the source of the smell was a beaker containing an unknown fluid that had been placed in the back of a pickup truck, Newdall said.
Newdall said scientists at ImmunePath, Inc., a biotech firm and tenant at the technology park, had been using the beaker and apparently put it outside after it started to smell.
The San Mateo County Hazardous Materials Response Team was called out to the scene, Newdall said.
Newdall did not specify what the fluid was, but said it was not hazardous and was deemed to be of no risk to any neighbors.
The scene was cleared by about 7 a.m.