A number of environmentally hazardous substances are used in the process of flax roving preparation for spinning. An alternative to them can be the use of electrochemical activated aqueous solutions. However, the metastability of such solutions requires time tracking of their properties’ relaxation. This article pre-sents experimental data on the relaxation of relevant solutions that can be used for a well-founded selection of flax roving treatment procedures to ensure a re-quired quality of flax yarn. It has been experimentally proven that the use of ECA solutions for preparing rovings for spinning allows to obtain high quality yarn as well as significantly reduce wastewater pollution and improve the envi-ronmental situation in the places of their emissions.