Quantitative Risk Assessment


Quantitative Risk Assessment (QRA) is a method for calculating individual, environmental, employee and public risk levels.

Why QRA is needed?

Satisfactory demonstration of acceptable risk levels is very much required in chemical industries. Furthermore, it is also required during plant modification and changes in operational manning levels.

Who needs QRA?

Facilities requiring Quantitative Risk Assessment (QRA) studies may include production and processing facilities, high pressure pipelines or storage and importation sites including liquefied natural gas (LNG). QRA may be a requirement of applicable legislation and/or internal company governance to show that risks are identified and controlled to an acceptable level. The criteria for risk acceptability may be defined by local regulations or company / investor policy.


  1. To identify the risk resulting from the hazards (primarily for gas dispersion, explosion overpressure, fire and toxic gas),
  2. To study and foresee the effects of such risks on the workers, public, property and environment,
  3. To evaluate the existing safeguards & to recommend necessary control measures to prevent or minimize risk, if existing safeguards are not adequate,
  4. To provide basis for the type and nature of its On-Site and Off-Site Emergency, information for Emergency planning and evacuation.
  5. To comply the legal requirement by various safety and environment laws of the country,
  6. Provide conclusions and demonstrate that risks are ALARP when recommendations are implemented.

Our Methodology

We carry out Risk Assessment for existing as well as proposed units using most prevalent and relevant methodologies that involve the steps of identifying hazards associated with the operations and selecting worst case scenario for consequences estimation. Adopting reputed software models for consequences estimation. We suggest the measures to minimize or mitigate risks to meet appropriate acceptability criteria and/or demonstrating that the risks are as low as reasonably practicable (ALARP).

The method may include some or all of the following

  • Identification of Hazards
  • Selection of scenarios to be modeled
  • Estimation of Frequency of Failure(By Fault Tree Analysis OR Event Tree Analysis)
  • Consequence Analysis: An analysis of the severity / consequence of accident scenarios
  • Predicted number of fatalities / casualties for each scenario
  • Estimation of Individual risk
  • Group / Societal risk
  • Potential loss of life
  • Location specific risk
  • Preventive / mitigation measures

We have experience of modeling most major accident consequences including fires, explosions, toxic gas releases and hazardous spills. A wide range of software modeling tools is used to assess the effects of such hazards on people (on- and off-site), the asset and the environment.

Our Experience

We have performed several QRA studies for various sectors i.e. Chemical, Pharmaceuticals, Oil & Gas, etc.

Customer References