Safety procedures in the transport of flammable and oxidizing materials - a case study of thiophene and zinc bromate

The transport of dangerous goods by road presents a complex safety challenge requiring the implementation of specific procedures defined by ADR regulations. The objective of this paper is to examine, through a comparative analysis of two dangerous goods belonging to different ADR classes-thiophene (UN 2414, Class 3) and zinc bromate (UN 2469, Class 5.1)-whether the ADR classification system adequately reflects fundamental differences in hazard mechanisms and dominant risk scenarios in road transport. Employing a deductive methodological approach, the research systematically analyzes ADR 2025 regulations, identifies specific requirements for each material, and conducts a comparative analysis of safety procedures. Results demonstrate fundamental differences in requirements stemming from opposing hazard mechanisms: thiophene as a fire source requires explosion-proof protection (FL vehicle, Kemler number 33, test pressure 250 kPa), whereas zinc bromate as a combustion intensifier requires stricter vehicle cleanliness control and separation from flammable materials (CV24 provision, SGAV tank, test pressure 100 kPa). Different packing groups (II for thiophene, III for zinc bromate) and transport categories (2 and 3, respectively) reflect varying levels of inherent risk. Comparative analysis identifies key dimensions of differentiation: packaging and containment, electrical protection, vehicle marking, mandatory equipment, and emergency procedures. The scientific contribution of this work is manifested in the systematization and explanation of ADR classification logic through the lens of a concrete case study, providing practical guidelines for transport companies, safety advisors, and all participants in the dangerous goods transport chain.