Isa-tr84.00.09 Exclusive Jun 2026

, titled “Cybersecurity of Safety Instrumented Systems (SIS)” , is a technical report that guides users through the process of identifying, analyzing, and mitigating cyber threats that could impact the safety functions of a SIS.

This wasn’t just a checklist—it was an . It said that safety and security are not separate columns to be reconciled later, but two faces of the same reliability coin.

It is a standalone standard but a companion document to ISA-84.00.01 (IEC 61511 mod) . It provides a risk-based methodology to answer a critical question: How much cybersecurity is enough for my safety system? isa-tr84.00.09

2. The Intersection of Safety and Security (ISA-TR84.00.09 and ISA/IEC 62443)

In other words, the report predicted the exact attack logic used years later in the (2017), which targeted a Schneider Electric Triconex safety controller to sabotage a petrochemical plant in the Middle East. It is a standalone standard but a companion

Focuses on mitigating random hardware failures and systematic design errors to prevent unsafe scenarios.

Most people skim the report and remember a single table—Table 4—which maps cybersecurity countermeasures (firewalls, whitelisting, access control) to safety lifecycle phases. Boring? Maybe. But that table gave birth to an entire workflow that is still cutting-edge today: The Intersection of Safety and Security (ISA-TR84

For an end-user (owner/operator) or system integrator, here is a practical roadmap:

Introduction of Security Protection Ratings (SPR) similar to maturity levels. Modern Security Concepts:

The report provides a catalog of countermeasures mapped to each layer of the SIS. Examples include:

Meeting regulatory demands for cyber-resilient safety systems. Conclusion