A swath of white substance that washed ashore near the Santa Monica Pier on Wednesday, prompting a brief beach closure, was fatty acid, officials said.
Test results showed the substance was linoleic acid, similar to common cooking grease, according to the Los Angeles County Fire Department lifeguard division. The substance is not hazardous to the public, they said.
Investigators with the Fire Department's Hazardous Materials Division have not determined the source of the leak.
The fatty gunk forced lifeguards to close an area of Santa Monica Beach while crews investigated the substance.
Santa Monica Beach maintenance workers began cleaning up the sand after 11 p.m., filling about half of a beach trash can with the fatty mess.
Linoleic acid is a fatty substance found in nuts, seeds and vegetable oils. The fatty acid can be used for making oil paint and varnish.