Which of the following SLs provides no specific security requirements?

SL-0 is identified as the security level within the ISA/IEC 62443 framework that provides no specific security requirements. This level represents an environment that is entirely unprotected and does not implement any security measures or controls. It serves as a baseline for understanding the progression of security in more advanced levels, where specific controls and protections are introduced to mitigate risks.

Understanding this foundational aspect is essential as it highlights the importance of movement toward higher security levels (from SL-1 upwards) that do have defined security requirements, focusing on different aspects of risk mitigation, policy enforcement, and security control implementation. This framework guides organizations aiming to enhance their cybersecurity posture by identifying where they currently stand and where they need to go to better safeguard their critical infrastructure.