The article presents a draft unified classification of harmful and/or hazardous factors of working conditions for subsequent identification and assessment of any possible occupational risks of employees of various types of economic activity within the framework of the implementation of a risk-based approach in the organization of labor protection at enterprises. In total, 134 harmful and/or dangerous factors present in the production environment and work processes were identified, which were divided into six main groups: physical, chemical, biological, mechanical, psychophysiological, and general industrial pollution. A five-level classification of the main harmful and/or dangerous factors of the production environment and the labor process and their subspecies is proposed. The largest group consists of physical factors, such as industrial noise, vibration, various types of radiation, lighting conditions at enterprises, exposure to electric current and electric arc, the threat of fire or explosion, as well as climate and microclimate conditions and aerosol composition of the air. The conducted research and the creation of a detailed classification of possible harmful and dangerous effects on employees of enterprises formed the basis of a new concept of providing personal protective equipment against harmful factors of production in the Republic of Kazakhstan.