Gas-Leak Detection 

How to Conduct a Gas-Leak Detection Risk Assessment in Chemical, Oil & Pharma Industries

by Jeet Sodagar on 04/11/25

Introduction

Gas leaks remain one of the most serious hazards in industrial environments — whether in chemical plants, oil and gas refineries, pharmaceutical facilities or dyes and pigment units. A small leak of a toxic, flammable, or oxygen-displacing gas can cause explosions, fires, or serious health risks. A thoughtful, systematic gas-leak detection risk assessment is the first step toward preventing such disasters. 

Alongside sound procedures, using high-quality, industry-grade detection systems significantly improves safety and compliance. In this context, solutions from ESPM SENSE — such as FGD-X, PGD-X, and the area monitoring panel AMP-X — can help you build a robust gas-safety infrastructure. 

Why a Gas-Leak Risk Assessment Is Critical

  • Protect human life and health : Many industrial gases are toxic or asphyxiant (e.g. chlorine, ammonia, CO₂, solvents), and even small leaks can harm or incapacitate workers.
  • Prevent fire, explosion, and property damage : Flammable gases or vapors (methane, LPG, VOCs) accumulating undetected can ignite under the right conditions.
  • Ensure uninterrupted operations : Leaks often lead to emergency shutdowns, production losses, costly clean-ups, or legal/regulatory consequences.
  • Meet regulatory compliance & environmental standards : Safety audits and environmental regulations increasingly demand active leak detection and monitoring. 

Common Gas Hazards in Different Industries

  • Chemical plants : Toxic or corrosive gases like chlorine, sulfur dioxide, ammonia, etc.
  • Oil, petrol & petrochemical units : Flammable gases and vapors (methane, LPG, hydrocarbon gas), risk of fire/explosion.
  • Pharmaceutical production : Solvent vapors, VOCs, inert gases — risk of toxicity, oxygen displacement, or process contamination.
  • Color, dye & pigment manufacturing : VOCs, solvent vapors, gases used in chemical treatments — flammability, toxicity, inhalation hazards.

7 Key Steps in a Gas-Leak Detection Risk Assessment

1. Map all potential leak sources

  • Survey valves, flanges, storage tanks, pumps, seals, solvent-handling zones, pipelines, reactors — anywhere a leak can occur.
  • Use facility drawings (P&IDs, GA drawings) to ensure you don’t miss concealed or seldom-visited areas. 

2. Characterize the gases: type, behaviour & risk

  • Determine whether the gas is toxic, flammable, asphyxiant or a volatile organic compound (VOC).
  • Understand gas properties: heavier-than-air gases settle downward, lighter-than-air gases rise, vapours may spread slowly — this affects detector placement and sensitivity requirements. 

3. Assess ventilation and air-flow patterns

  • Check natural airflow, forced ventilation, presence of confined spaces, “dead zones”, ducts or pits where gas could accumulate.
  • Poor ventilation areas demand more sensitive detection and perhaps multiple detection points. 

4. Define hazard zones and area classification

  • Based on gas type, frequency of presence and leak probability — classify zones (hazardous, safe, confined space, high-risk area, etc.).
  • This helps in choosing appropriate detection equipment and ensuring compliance with safety regulations. 

5. Select suitable gas-detection technology

Choose sensors according to gas type:
  • Electrochemical for toxic gases (e.g. chlorine, CO),
  • Catalytic pellistor for combustible gases (methane, LPG),
  • PID/NDIR for VOCs, solvents, CO₂, etc.
Use fixed detectors for continuous surveillance in critical zones; portable detectors for maintenance, confined-space entry, or periodic checks. 

6. Plan detector placement carefully

  • Install detectors close to leak-prone sources (valves, storage tanks, solvent-handling sections).
  • Also place detectors at worker breathing zones, common working areas, confined spaces, and air-intake/exhaust points.
  • For larger facilities or complex layouts, integrate on an area monitoring panel for centralized monitoring. 

7. Establish documentation, SOPs and contingency plans

  • Maintain a leak-risk report, gas-dispersion models (if possible), detector-placement layout, calibration schedules, alarm thresholds.
  • Prepare clear Standard Operating Procedures (SOPs): what to do if an alarm triggers, evacuation protocols, maintenance checklists.
  • Plan periodic reviews — especially after major process changes or expansion. 

Common Mistakes & Lessons Learned in Risk Assessments

  • Relying only on portable detectors (reactive approach) rather than continuous detection — leaks often go unnoticed until conditions worsen.
  • Using a “one-size-fits-all” detector — wrong sensor type for specific gas leads to missed hazards.
  • Ignoring confined spaces, seldom-visited corners or ventilation dead zones — often where leaks accumulate dangerously.
  • Skipping regular calibration and maintenance — sensors drift over time, causing false negatives or alarms.
  • Not documenting or reviewing SIP (site inspection plan), SOPs and response protocols — leaving response reactive rather than systematic. 

Why Combining Fixed, Portable and Central Monitoring Improves Safety

  • Continuous monitoring at critical points: A fixed detector like ESPM SENSE’s FGD-X continuously watches for toxic, flammable, asphyxiant or VOC gases at key locations.
  • Flexible checks and confined-space safety: A portable detector like PGD-X allows safety teams to check for leaks during maintenance, inside enclosed or confined areas, or during shutdown/start-up operations.
  • Centralized oversight for large facilities: An area monitoring panel such as AMP-X (for centralized connection to multiple detectors) helps integrate signals from multiple fixed detectors — giving a complete view of gas-safety status across a plant.

    • By combining fixed, portable and panel-based monitoring, you get 360° safety coverage — from real-time detection to periodic checks, and from local zones to entire plants. 

    Conclusion

    Gas-leak detection isn’t a one-time exercise — it’s a continuous commitment to safety, compliance, and responsible operations. A structured risk assessment helps you map hazards, understand gas properties, foresee leak pathways, and plan detection strategies suited for your industry’s needs.

    Need Help Interpreting Your Reports or Choosing the Right Detection Solution?
    Our experts are here to assist. Whether you need custom dashboards, on-site inspection, or training in interpreting reports—we’re just a call away.

    Contact ESPM SENSE Pvt. Ltd. Let’s create safer, smarter industrial environments—together. 

    CRM form will load here