The article presents a method for determining machine safety by calculating the safety integrity level (SIL). Problems of machine safety were presented in the context of applicable legal regulations and international standards. On the basis of the literature and standards, methods for determining the safety integrity level, quantitative measures used within the PN EN 62061 standard and basic concepts related to functional requirements have been presented. In addition, the author compares the method of determining the SIL level from the PL level of safety assurance. The article is a continuation of the author's previous publication on machine safety.