Fires: How Hot, Dry Conditions Can Cause Spontaneous Combustion

Auto ignition fires can occur when materials undergo a chemical reaction in the environment in which the materials are stored.  Auto ignition is also known as self-ignition or spontaneous combustion.  In order for auto ignition to occur, the materials must be able to self-heat to the point that a thermal runaway condition occurs.

Commonly cited instances of spontaneous combustion at ambient temperature and atmosphere are when porous organic solids like cotton fabrics or wood are soaked with animal or plant fats and oils, like linseed oil.  The combination of the two may occur inadvertently.   For example, rags or brushes used for painting might be cleaned with a solvent and left to dry.

Another common instance of auto ignition can occur during the accumulation and storage of biomass materials.  Mulch piles, haystacks, sawdust or wood chip piles can self-heat during natural biological activity and decomposition.  Coupled with dry and hot ambient conditions, piles of biomass materials can become prone to auto ignition.

ARCCA’s engineers have the experience and qualifications to handle all of your fire investigation needs, including cases of auto ignition.

PETER CHEN, M.S.M.E., M.B.A., P.E., CFEI, ACTAR, is a mechanical engineer at ARCCA specializing in Accident Reconstruction, Fire Cause/Origin, Product Failure/Liability, Car/Truck Failure Analysis, Industrial Equipment, Worksite Safety, Aviation, Medical/Rehabilitative and Exercise Equipment, Warnings and Instructions, and Transportation, including Railroad incidents.   He is ACTAR-certified, a Certified Fire/Explosion Investigator, a Certified Crash Data Retrieval Analyst and a JLG Certified Equipment Trainer.