Introduction. The article is devoted to the issues of pseudolegal turnover of potentially dangerous materials, substances and products as a source of formation of means of mass destruction of people while committing crimes of sabotage and terrorist orientation. Theoretical analysis. The causes and genesis of the pseudo-legitimate turnover of edged weapons, barrelled gas weapon and firearms, new psychoactive substances with nonspecific increased toxicity or other pronounced damaging features are revealed in detail. This article formulates recommendations for the prompt identification of relevant threats during forensic medical, forensic chemical, forensic ballistic and other types of examinations, the development of preventive measures, including proposals to improve existing legislation. The authors consider these problems in the context of the main provisions of the Decree of the President of the Russian Federation of March 11, 2019 No. 97 “Fundamentals of State Policy of the Russian Federation in the field of ensuring chemical and biological safety...”. Results. The authors provide justification for the need for unification, primarily of the conceptual and terminological apparatus and methodological foundations of a forensic expert study in the circumstances of the pseudo-legal turnover of potentially dangerous materials, substances and products (PDMSP), taking into account the possibilities of the integrated use of the achievements of various areas of scientific and practical knowledge.