The effectiveness of standardisation as a form of regulation of processes and results of activity in all spheres of production-technical, commercial-economic, social and other relations is confirmed at the international and regional levels, in the scope of standardisation work in countries with a developed market economy. World and domestic experience has revealed a wide range of problems and tasks that can be solved with the involvement, and sometimes exclusively, by means of standardisation, as well as various forms and methods of solving these problems, which are determined by the state and trends of economic development, conditions and factors of its functioning. The level of scientific and technical progress in many sectors of the world economy, the growth rates of international trade pose new challenges to standardisation. In these conditions, standards become the main economic tool for rationalisation and harmonisation of international trade as an integrated expression of the effective economic development of the country. Harmonisation of domestic standards with international and regional standards creates the necessary conditions for the creation of competitive products based on the updating of the current stock of state and interstate standards; development of technical legislation (technical regulations) regulating issues of safety of products and services for life and health of people, environment; formation of a system of standards of information interaction, in which electronic means of communication make it possible to strengthen international technical cooperation in all spheres of human activity. Certain aspects of improving the quality and competitiveness of products, including by means of standardisation, have been considered in the works of domestic and foreign scientists. However, there are practically no scientific works devoted to ensuring the competitiveness of processes of transportation and storage of petroleum products by means of harmonisation of national standards. The importance of the considered problem and its insufficient development for the economy of Ukraine, its industries and enterprises determine the relevance of the research topic. In this scientific work the analysis of different approaches to the determination of the loss of petroleum products was carried out with the help of regulatory documents approved at the state level. A comparative analysis of the document used for a long time in the post-Soviet space and the document that replaced it in Ukraine was carried out. The approach to determining the loss of organic liquids from tanks of various designs in the USA was analysed, in particular, the possibilities and limitations of using the functions of the TANK 4.0 program to calculate the loss of oil products by evaporation from tanks were studied