LIESIPALO – ignition, effects, and prevention of cooktop fires

Liesipalo, cooktop fire, hob fire – is a common type of residential fires. This project aims at finding the reasons for their ignition, studying the consequences on indoor environment safety, and assessing ways of preventing or mitigating them.

The project is funded by Palosuojelurahasto.


  1. Jhatial, T. Thermal characterization of electric stoves. Aalto University. MSc Thesis. 2021. 

Conference presentations

  1. Jhatial, Tarique; Hostikka, Simo; Thermal Characterization of Electric Cooktops. Palotutkimuksen päivät 2021. 8.9.2021. Palotutkimusraati.
  2. Simo Hostikka, Emmanuelle Castagnoli, Raimo Mikkola, Rauli Törrö, Rahul Kallada Janardhan, Heidi Salonen. Haitallisten aineiden syntyminen ja tuuletus liesipaloissa – laboratoriokokeet. Palotutkimuksen päivät 2023. 4-5.9.2023. Palotutkimusraati

Research results

WP 2: Thermal characterization

Thermal characterization of three types of electric stoves were performed using thermocouples, IR camera, and Hukseflux SBG01 heat flux gauge.

These results are, of course, specific to the particular cooktop models, but some general observations can be made:

  • Glass ceramic and induction cooktops are faster than electric coil.
  • Induction cooktop had a safety feature that limited the peak temperatures of cast iron and carbon steel pans lower than at other cooktops.
  • Aluminum pan peak temperatures were lower than cast iron and carbon steel pans at all cooktops.

WP2: Ignition tests

Ignition tests were carried out for different food and kitchen materials.

In addition, the heat release rates were measured using the oxygen consumption calorimetry.

Measurement of sunflower oil heat release rate on aluminum pan and ceramic glass cooktop. Photo: Simo Hostikka

IR video 1 : 23 g of sunflower oil vaporizes from a pan, creating a foaming char.

IR video 2: 10 x 10 cm2 version of a pizza box heated and ignites (Warning: temperature scale not calibrated)

IR video 3: 23 g canola oil in cast iron pan, ignites to flaming.

WP 3: Indoor health

Third series of tests examines the effect of small kitchen fires and burned food on the indoor air quality. For this study, we built a 2 x 2 x 2.5 m3 room with mechanical ventilation.

VIDEO: Paper towel roll (15 min min test, 50 x speed-up)

Two pieces of sausage in a pan:

Posted by Simo Hostikka

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