Fire officials warn residents of spontaneous combustion Fire officials warn residents of spontaneous combustion (December 10, 2003)

By John Flood

Special to the Almanac

The three-alarm fire that extensively damaged two homes on Russell Avenue in Portola Valley on October 13 started by spontaneous combustion in a pile of wood that had been treated with a linseed-based wood stain a day or two before, the Woodside Fire Protection District has confirmed.

Fire investigators concluded that the blaze began in a poorly ventilated area of the garage at 135 Russell Ave., said Denise Enea, the district's fire prevention officer.

District officials are trying to educate the public about sources -- and prevention -- of spontaneous combustions fires.

"Several of the fires we've had this year have been caused by spontaneous combustion from oil-stained rags," said Ms. Enea. Many wood stain products are based on linseed oil, she said.

"Linseed oil products generate their own heat," she said. "Rags [with linseed oil] should go in a container with a lid. Or dry them out in an open, ventilated area.

"Homeowners need to watch their contractors and be careful [if they do the staining] themselves."

Spontaneous combustion occurs when there is enough oxygen to permit oxidation but not enough to dissipate the heat as fast as it is produced, according to the Woodside Fire Prevention District Web site.

The Web site offers these tips: Hang oil-soaked rags on a clothesline outside or in an area where plenty of air circulates around the rags. Read labels on paint products and take the precautions recommended. Other natural oils such as mineral, fish, cottonseed and cod liver can generate heat and pose fire risks.

For more information, go to woodsidefire.org or call the Woodside Fire Protection District at 851-1594.

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