Episode 46 - Process Safety Information for Process Safety Management

Episode 46 explains the Process Safety Information (PSI) element of OSHA’s Process Safety Management Standard (29 CFR 1910.119). Dr. Ayers emphasizes that PSI is the foundation of the entire PSM program — every other element depends on it being complete, accurate, and up‑to‑date.

The core message: If your PSI is wrong, every decision built on it is wrong.

  🧭 Purpose of Process Safety Information

PSI ensures that facilities have accurate technical information about:

• The chemicals they use

• The technology of the process

• The equipment involved

This information is essential for:

• PHAs

• Operating procedures

• Training

• Mechanical integrity

• Emergency planning

• MOC and PSSR

PSI is the data backbone of process safety.

  🧪 Three Major Categories of PSI

Episode 46 breaks PSI into three required components:

  1. Information on Highly Hazardous Chemicals

This includes:

• Toxicity

• Permissible exposure limits

• Physical and chemical properties

• Reactivity

• Corrosivity

• Thermal and chemical stability

• Hazardous effects of inadvertent mixing

This information helps workers understand what can go wrong.

  2. Information on Process Technology

Facilities must document:

• Block flow diagrams or P&IDs

• Maximum intended inventory

• Safe upper and lower operating limits

• Consequences of deviating from limits

• Process chemistry

• Process design basis

This information defines how the process is supposed to work.

  3. Information on Process Equipment

This includes:

• Materials of construction

• Piping and instrument diagrams (P&IDs)

• Relief system design

• Electrical classification

• Design codes and standards

• Safety systems and interlocks

• Ventilation system design

This information ensures equipment is designed, installed, and maintained safely.

  🔍 Why PSI Must Be Accurate

Dr. Ayers stresses that inaccurate PSI leads to:

• Incorrect PHAs

• Wrong operating limits

• Ineffective procedures

• Poor training

• Mechanical integrity failures

• Startup and shutdown hazards

PSI errors often show up as root causes in major incidents.

  🔄 PSI and Management of Change (MOC)

A major theme of the episode:

• Any change to chemicals, equipment, or process technology must trigger an MOC

• MOC must ensure PSI is updated

• Updated PSI must flow into procedures, training, and PHAs

If PSI is not updated after changes, the entire PSM system becomes misaligned.

  🧪 Common PSI Failures Highlighted in the Episode

Dr. Ayers calls out typical weaknesses:

• Outdated P&IDs

• Missing relief system design information

• Incorrect operating limits

• Incomplete chemical hazard data

• PSI stored in multiple locations with conflicting versions

• PSI not updated after modifications

• Operators unaware of current PSI

These failures create blind spots that increase risk.

  🔗 How PSI Connects to Other PSM Elements

PSI is the foundation for:

• PHA — hazard analysis depends on accurate PSI

• Operating Procedures — must reflect PSI limits

• Training — workers must learn from current PSI

• Mechanical Integrity — equipment specs come from PSI

• MOC — PSI must be updated after changes

• Emergency Planning — responders rely on PSI

If PSI is wrong, every downstream element is compromised.

  🧑‍🏫 Leadership Responsibilities

Safety leaders must:

• Ensure PSI is complete, accurate, and controlled

• Maintain a single source of truth

• Require updates through the MOC process

• Ensure operators and maintenance personnel have access to PSI

• Audit PSI regularly for accuracy

• Treat PSI as a living system, not a binder on a shelf

The episode’s core message: PSI is the foundation of process safety. Build it strong, keep it current, and everything else becomes easier.