Behaviour of coal-biomass blends at elevated temp. was studied to evaluate the fire hazards in fuel grinding systems of pulverized coal boilers. Blends of bituminous coal fine (grain size below 0.2 mm) and ground sawdust, willow or sunflower husk pellets (grain size below 0.425 mm) were studied by DTA with mass spectroscopy up to 700 degrees C under Ar and gasified with air in fixed bed in a large lab. plant. The gaseous prods. of the gasification were analyzed for H(2), CO, CO(2) and MeH. The biomass was decompd. at 250-380 degrees C to H(2)O, MeH and CO, The coal was decompd. at above 420 degrees C to H(2) and MeH. The gasification of the blends showed an anusual temp. jump at 200 degrees C connected with an increase of pressure. This fact was explained by fast formation of flammable gases (CO, H(2), MeH) and their combustion.