The subject of this bachelor thesis is hazards and safety measures when working with acids and alkalis. The introductory part defines the concepts of acid and alkali, their classification, and the basic physical-chemical parameters that define them. Acids and alkalis are the most well-known corrosive substances, and they are especially dangerous in their concentrated form. They are encountered in the form of liquids, solids, vapors, dust, and mist, depending on different application conditions and atmospheric conditions. The same hazards arise when working with alkalis as with acids. The most common injuries during the production, handling, transport, storage or use of acids and alkalis are skin and eye injuries, which is why the instructions and rules of handling should be strictly followed. When working, especially with concentrated acids and alkalis, the use of protective glasses and gloves is mandatory. Acids and alkalis have caustic and corrosive properties. For the proper use of acids and alkalis, it is important to be familiar with the instructions and notices, i.e., the Safety Data Sheets (SDS). The most important steps are those related to dealing with the injured person, so it is important to keep the intervention plan in mind.