The European standard EN ISO 20345 classifies safety footwear into different protection classes. The standard’s basic requirements for optimal protection apply to the upper material (leather, rubber or other synthetic materials) and the toe cap (steel, aluminium or plastic). The slip resistance of the sole is also crucial. Work shoes that only meet the basic requirements of the EN ISO 20345 standard are classified as protection class SB. The individual protection classes extend these basic requirements with specific properties.