The article presents a study of chronic phytotoxicity in the area of influence of three small boiler houses, 2 of them run on coal, one on fuel oil. As a result of the research, it was revealed that both selected crops have growth inhibition. At the same time, oats show greater resistance to contamination than clover. At the same time, the root system is less susceptible to the inhibitory effect. The greatest negative impact is observed in the area of the boiler house running on fuel oil.
Keywords: small boiler houses, phytotoxicity, biotesting, negative impact, soil, oats, clover