Toxicity assessment of unbounded composites based on birch wood and hydrolysis lignin

In this work, the author studied the toxic properties of plastic without resins (PWR) obtained from compositions with a different ratio of wood filler (birch sawdust) and powdered hydrolyzed lignin (HL), which is a waste from hydrolysis production,. The following indicators were adopted as criteria for the toxicity of the studied PWR: the gross content of heavy metals in the feedstock; the degree of impact on the environment and human health; release of free formaldehyde from PWR; change in the pH of the aqueous extract when exposed to PWR; biotesting of water extracts from PWR. It has been established that the processes of self-purification in HL were either absent or were at an extremely low level of activity. The toxic properties of HL did not depend on the content of inorganic pollutants (heavy metals and arsenic) in it, but largely depended on the content of hydrolyzed lignin itself. The studied PWR samples of various compositions, primarily containing HL as a filler, were not a source of significant release of free formaldehyde upon short-term contact with water at room temperature. The degree of toxicity of the aqueous extract from PWR directly depended on the acidity of the HL. The acidic environment of water formed during prolonged exposure to PWR did not comply with sanitary standards and promoted other negative processes affecting the environment and human health. In the general assessment of the toxicity of the studied samples, we can talk about PWR highly toxic effects and influence. both during explication and after the loss of consumer properties. This may significantly limit the use of these materials, both in relation to human health and in relation to the natural environment.