In high-hazard industries like oil and gas, petrochemicals, and chemical manufacturing, the potential for catastrophic incidents such as fires, explosions, or toxic releases demands a proactive approach to safety. Inherently Safer Design (ISD) is a philosophy that prioritizes eliminating or reducing hazards at the design stage, rather than relying solely on add-on safety measures. An ISD Review is a structured process to evaluate and integrate these principles into a project, ensuring risks are minimized from the outset. This article explores the principles, methodology, and practical applications of ISD Review, with insights into how Cormat Group implements this approach to enhance safety and compliance in complex environments.

What is an Inherently Safer Design (ISD) Review?

An Inherently Safer Design (ISD) Review is a systematic evaluation conducted during a project’s lifecycle—typically in the conceptual, design, or operational phases—to identify opportunities to eliminate or reduce hazards through design choices. Unlike traditional safety measures that rely on external controls like alarms or shutdown systems, ISD focuses on making processes inherently safer by minimizing hazardous materials, simplifying operations, or reducing the potential for human error. The goal is to reduce risks to As Low As Reasonably Practicable (ALARP) by prioritizing inherent safety over engineered or procedural solutions.

ISD is guided by four key principles:

• Minimization: Reducing the quantity of hazardous materials or energy.
• Substitution: Replacing hazardous substances or processes with safer alternatives.
• Moderation: Using less hazardous conditions, like lower pressures or temperatures.
• Simplification: Designing processes to be less complex, reducing the potential for errors.

In industries governed by regulations like the UK’s Control of Major Accident Hazards (COMAH) or OSHA’s Process Safety Management (PSM), ISD Reviews are critical. For example, in a chemical plant, an ISD Review might recommend using a less toxic solvent to reduce health risks, rather than relying on ventilation systems. By embedding safety into the design, ISD Reviews enhance long-term safety and efficiency.

Why is ISD Review Important?

ISD Reviews are essential for managing risks in high-hazard industries. Their key benefits include:

• Enhanced Safety: By eliminating or reducing hazards, ISD minimizes the potential for fires, explosions, or toxic exposures, protecting workers and communities.
• Cost Savings: Addressing hazards at the design stage reduces the need for costly add-on safety systems or retrofits.
• Regulatory Compliance: Regulations like COMAH and PSM encourage ISD principles, with reviews providing evidence of due diligence.
• Environmental Protection: Reducing hazardous materials or emissions minimizes environmental impacts, like spills or air pollution.
• Operational Efficiency: Simpler, safer designs reduce downtime and maintenance costs, improving productivity.
• Stakeholder Trust: Cormat Group builds confidence among employees, regulators, and communities by prioritizing inherent safety through ISD Reviews.

A 2023 report by the Health and Safety Executive (HSE) found that facilities incorporating ISD principles reduced major accident risks by 42%, highlighting the transformative impact of this approach.

Key Components of ISD Review

ISD Reviews are built on several core elements that ensure a comprehensive approach to inherent safety:

1. Hazard Identification

Identify potential hazards, such as flammable gases, toxic chemicals, or high-pressure systems, that could lead to major accident hazards (MAHs).

2. ISD Principle Application

Apply the four ISD principles (minimization, substitution, moderation, simplification) to eliminate or reduce hazards through design changes.

3. Risk Assessment

Evaluate the likelihood and consequences of remaining hazards, using qualitative or quantitative methods to prioritize design improvements.

4. Control Measures

Identify additional controls, like safety instrumented systems (SIS) or procedural safeguards, for risks that cannot be eliminated through ISD.

5. ALARP Demonstration

Demonstrate that risks are reduced to ALARP by showing that inherent safety measures are maximized and residual risks are managed cost-effectively.

6. Documentation

Create detailed ISD Review reports, including hazard lists, design recommendations, and ALARP rationale, to support audits and compliance.

7. Stakeholder Engagement

Involve multidisciplinary teams, including engineers, operators, and safety professionals, to ensure practical and effective design solutions.

Methodology for Conducting an ISD Review

Conducting an ISD Review requires a structured, collaborative approach that integrates technical expertise, risk assessment, and design innovation. Here’s a step-by-step guide:

Step 1: Define the Scope

Determine the project phase (e.g., conceptual design, detailed design, or operation) and the scope, such as a specific process unit or an entire facility. Align with project goals and regulatory requirements.

Step 2: Assemble a Multidisciplinary Team

Form a team of experts, including:

• Process engineers to analyze technical designs.
• Safety professionals to assess hazards.
• Operations personnel to provide practical insights.
• Environmental specialists to evaluate ecological impacts.
  Cormat Group ensures diverse expertise to drive effective ISD Reviews.

Step 3: Gather Project Data

Collect relevant information, including:

• Process flow diagrams (PFDs) and piping and instrumentation diagrams (P&IDs).
• Material Safety Data Sheets (MSDS) for hazardous substances.
• Operational conditions (e.g., pressure, temperature, flow rates).
• Historical incident data or industry benchmarks.

Step 4: Identify Hazards

Use tools like Hazard and Operability (HAZOP) studies, Hazard Identification (HAZID), or What-If Analysis to identify hazards, such as:

• Process Hazards: Fires, explosions, or runaway reactions.
• Health Hazards: Exposure to toxic chemicals or ergonomic risks.
• Environmental Hazards: Spills, emissions, or waste issues.

Step 5: Apply ISD Principles

Evaluate the design against the four ISD principles:

• Minimization: Reduce the inventory of hazardous materials (e.g., smaller storage tanks for flammable liquids).
• Substitution: Replace hazardous substances with safer alternatives (e.g., water-based solvents instead of toxic ones).
• Moderation: Operate at milder conditions (e.g., lower pressures to reduce explosion risks).
• Simplification: Streamline processes to reduce complexity (e.g., fewer valves to minimize failure points).
  Brainstorm design changes to eliminate or reduce hazards.

Step 6: Assess Residual Risks

Evaluate the risks remaining after applying ISD principles, using:

• Qualitative Methods: Risk matrices to rank risks by severity and likelihood.
• Quantitative Methods: Quantitative Risk Analysis (QRA) or Layer of Protection Analysis (LOPA) to calculate risk levels, such as Individual Risk Per Annum (IRPA).
  Compare residual risks to tolerability criteria, like HSE’s Risk Tolerability Framework or COMAH thresholds.

Step 7: Identify Additional Controls

For risks not fully eliminated by ISD, implement controls, such as:

• Preventive Controls: Safety interlocks, pressure relief valves, or operator training.
• Mitigative Controls: Fire and gas detection systems, emergency shutdowns, or spill containment.
  Link controls to Health, Safety, and Environment Critical Equipment and Systems (HSECES).

Step 8: Conduct Cost-Benefit Analysis

Assess the cost and feasibility of ISD measures and additional controls, determining whether further risk reductions are reasonably practicable. For example:

• Compare the cost of reducing chemical inventory versus installing advanced detection systems.
• Evaluate the feasibility of process simplification versus adding redundant safety systems.
  Use decision trees or cost-benefit analysis to quantify trade-offs.

Step 9: Demonstrate ALARP

Show that risks are ALARP by:

• Documenting how ISD principles reduce hazards.
• Justifying why additional measures are not reasonably practicable, based on cost-benefit analysis.
• Comparing the approach to standards like IEC 61508 or ISO 31000.
  Provide a clear rationale for accepting residual risks.

Step 10: Document Findings

Create a detailed ISD Review report, including:

• Identified hazards and risk assessments.
• ISD design recommendations and their impact.
• Additional controls and their justification.
• ALARP rationale and residual risk acceptance.
  Ensure the report is clear, auditable, and aligned with regulatory requirements.

Step 11: Implement Design Changes

Work with design teams to incorporate ISD recommendations, such as modifying P&IDs or selecting safer materials. Verify implementation through design reviews or 3D modeling.

Step 12: Train and Communicate

Train personnel on:

• New design features and their safety benefits.
• Operating procedures for inherently safer processes.
• Emergency response plans for residual risks.
  Communicate findings to stakeholders, including operators and regulators, to ensure alignment.

Step 13: Monitor and Review

Regularly review the ISD implementation to reflect changes in:

• Operations (e.g., new processes or equipment).
• Regulations (e.g., updates to COMAH or PSM).
• Incidents (e.g., near-misses or lessons learned).
  Conduct follow-up ISD Reviews during project phases or after significant changes.

Conclusion

Inherently Safer Design (ISD) Review is a transformative approach to managing risks in high-hazard industries by embedding safety into the design process. By applying principles like minimization, substitution, moderation, and simplification, ISD Reviews eliminate or reduce hazards, ensuring safety, compliance, and efficiency. Cormat Group demonstrates how rigorous ISD Reviews drive safety excellence, protecting lives, assets, and the environment. Despite challenges like early integration and cost balancing, technology, collaboration, and regular reviews can overcome them. As industries evolve, ISD Reviews will remain essential for building safer, more sustainable facilities from the ground up.