Modern natural fibers, including flax, from the point of view of safety for humans should be considered in terms of their chemical composition. Regulatory documents on this issue are imperfect. The reasons for this are the lack of regulation of the chemical composition of flax fiber and normalization of heavy metals in it. Therefore, the object of this research is the process of development of regulatory documents on the safety of flax fiber of medical and sanitary-hygienic appointment. It is proposed to develop modern regulatory documents taking into account the requirements of the international standard Oeko-Tex Standard 100 and the requirements of the State Sanitary Norms and Regulations. At the same time, the maximum permissible concentration of all chemical elements in flax fiber is the regulation criteria. The proposed recommendations will contribute to increasing the requirements for fiber safety and minimizing the appearance of dangerous textile products on the Ukrainian market, the production of which spends considerable resources. The introduction of these results at the enterprise will contribute to the expansion of the assortment of safe products of medical and sanitary-hygienic appointment and markets for its sale.