Occupied building risk assessment (OBRA) is an assessment for occupants in buildings, who may face explosion, fire and toxic hazards, and is one of the main methods for facility siting. As stated in Regulation 5 - General Duties of Operators in the Control of Major Accident Hazards (COMAH) Regulations 2015, "Every operator must take all necessary measures to prevent major accidents and limit their impact on human health and the environment." Regulators hope to demonstrate that all risks are meet the criteria of ALARP. Therefore, without a proper OBRA, it is difficult to demonstrate that the risk to occupants in the building is ALARP, and OBRA is generally expected to be part of the regulator's COMAH safety report. Plants are always changing, and OBRA should keep pace with these changes as part of the Management of Change (MOC) process. It is recommended that OBRA should be updated and revalidated every 5 years based on revisions to hazards identified in the site COMAH Safety Report. However, due to the recent COVID-19 pandemic, factories may need to update them as soon as possible, as changes to the location or number of people in the building need to be assessed, as these may affect your individual or overall level of risk. As a standardized method, Zhunyun also suggests that Chinese enterprises can use OBRA to systematically understand the risks faced by the structures occupied by your colleagues.

Zhunyun will follow the relevant requirements of API 752,753, CIA and UK HSE when carrying out OBRA services

The specific steps consist of:

1) Identify the occupied building 

2) identify hazards

3) Assess the consequence from hazards by modelling

4) Screen buildings according to hazards

5) Prepare structure, strength and integrity data

6) Conclusions and suggestions for improvement