Process safety and risk management are key to the safe operation of all chemical process engineering practices. Accidents involving the unexpected release of hazardous materials can occur if appropriate safety measures are not carefully considered and observed by all parties. Potentially causing avoidable harm to people, property and the wider environment.
Carefully considered process safety management and risk management plans act to prevent the unintentional release of harmful substances by providing teams with the tools required to identify and mitigate potential risks. Typically using a combination of practical guidelines and dedicated security devices designed to both limit risk factors and monitor active equipment.
Industries that require process safety management
To ensure all workplaces that regularly handle toxic, reactive, flammable and hazardous materials are adequately protected against unintentional chemical accidents, the Federal Occupational Safety and Health Administration (OSHA) developed guidance known as the Process Safety Management of Highly Hazardous Chemicals standard. In this document, OSHA defines the industries and types of business that require process safety management.
The primary industries listed are:
- Construction
- Manufacturing and engineering
- Natural gas liquids
- Farm product warehousing
- Electric, gas and sanitary services
- Pyrotechnics and explosives manufacturers
- Wholesale trade
Specifically, OSHA rules apply to any companies that deal with more than 130 reactive and toxic chemicals, alongside flammable gasses and liquids in quantities of 10,000lbs or more.
Best practices for process safety and risk management
Identify potential hazards
Naturally, any effective process safety and risk management process must begin with an assessment of all essential processes that could contribute to the formation of significant hazards. In particular, process safety management intends to identify hazards related to:
- Fires and explosions
- Exposure to toxic materials
- Overpressure and underpressure
- Chemical reactivity
- Thermal expansion
- Static electricity
- Potential human errors
When conducting a review of potential workplace hazards, teams must:
- Collect and review existing data pertaining to active equipment / processes
- Perform frequent workplace inspections to identify new or recurring hazards
- Conduct an investigation into all injuries, illnesses, accidents and near misses to uncover any underlying issues that need to be addressed
- Group similar incidents together to identify trends in reported hazards
- Determine the severity of each group of hazards to prioritize corrective measures
Evaluate consequences and risks
With a clear understanding of the potential hazards present in the workplace, teams must evaluate the consequences and potential risks that those hazards pose.
Evaluations must involve:
- Reviews of previous incidents that may have occurred in the company/industry
- An analysis of event scenarios that could cause significant hazards
- Failure mechanisms that could help teams to identify potential risks
- Investigations into preventative and mitigative controls
- An analysis of the consequences related to potential event scenarios
- The assignment of a risk level to each event scenario
- Assessments regarding the significance of risks posed by each event scenario
- A review of the actions required to prevent and/or mitigate these risks
The completion of a considered evaluation process and risk assessment should lead teams to identify the need for specific safety equipment, the likelihood of certain hazards occuring and the consequences of those events.
Hazard and Operability Study (HAZOP)
The above process is often referred to as a HAZOP study. When performing a HAZOP study, organizations are expected to follow a 5 step process:
- Build a HAZOP team – Create a varied team with a team leader and multiple staff who are able to provide perspectives associated with different organizational roles, for example, design engineers, safety professionals, machine operators etc
- Identify processes – Teams must review existing documents and diagrams related to all interconnected equipment to locate sections where processes change (HAZOP nodes), these areas will likely experience the highest probability of hazards occuring
- Define parameters – Define the safe operating limits of all HAZOP nodes, in other words, determine the level of pressure / temperature / capacity etc that each process can safely handle before the likelihood of a hazard occurring becomes too great
- Safety monitoring – Safety monitoring concerns the establishing of safeguards and mitigation strategies designed to prevent HAZOP nodes from exceeding the safe parameters laid out in the previous step, using technologies and safety procedures
- Communicate results – All newly identified hazards and all newly implemented safety measures must be documented and communicated to appropriate employees, safety training can then be developed to hasten the adoption of new safety protocols
Develop and implement protections
Bespoke safeguards and protections can now be implemented to mitigate identified hazards. Typically, this will include installing a range of uniquely developed engineering controls like:
- Alarm systems
- Internet of Things (IoT) sensors
- Access control systems
- Relief valves
- Emergency shutdown systems
- Interlocks
In addition, administrative controls must also be developed such as training programs, audits and operating procedures; such processes act to ensure new safeguards are easily adopted.
For example, IoT sensors may be installed to monitor pressure levels in chemical storage facilities, with these devices connected to emergency shutdown systems. If levels exceed a safe value determined during previous risk assessment processes, connected systems will be instantly disengaged, alarms will be triggered and staff will know how to respond safely.
Further examples include the installation of a pan-tilt zoom camera system to address hazards involving the mishandling of chemicals in transit, the use of relief valves to automatically reduce pressure levels in hazardous areas, and the development of early warning systems designed to alert employees and safety officers of potential risks before hazards can form.
Conclusion
Performing detailed, frequent process safety and risk management procedures is essential in keeping employees and facilities safe from hazards. All businesses that handle dangerous chemicals must follow these principles to identify, analyze and address potential hazards, as well as to develop and evaluate suitable safeguards to continuously improve on-site safety.