Around 40% to 50% of process safety incidents and/or major losses in petrochem industries occur during start-ups, shutdowns and infrequent events

Restarting of manufacturing operations following idle periods can increase the susceptibility to loss such as fire, explosion, or machinery breakdown. This is especially because perceived stress and pressure on both the equipment and workforce is typically higher than during normal operation, explains Kirsty Handley, senior risk engineer at Swiss Re Corporate Solutions. 

Studies indicate that in the refining, petrochemical and chemical industries, around 40% to 50% of process safety incidents and/or major losses occur during start-ups, shutdowns and other events that occur infrequently.

Pre-start up safety reviews are one approach used in these industries to reduce the likelihood of loss, and some of those general principles are very valuable  for other industries as discussed here.

Making thorough pre-start up plans and checks can help ensure safe return to operation and avoid unnecessary set-backs  and/or further business interruptions. Fire is a particular concern and every effort should be made to ensure fire detection and protection systems are in working order.

The following precautions should be considered, advises Handley:

Changes since previous  operation:

  • Consider what is different or has changed since previous operations, such as equipment, layout, raw materials, operating conditions, organisation.
  • Review and update risk assessments, operating procedures and training materials, business continuity management systems, and other documentation accordingly.

Staff and Resources:

  • Check that key personnel are identified and available.
  • Check minimum staffing numbers  are available.
  • Consider for start-up operations, it may be advisable to limit personnel in hazard exposed areas  to those necessary for start-up.
  • Confirm refresher training for start-up of critical machinery / processes / emergency procedures been carried out where necessary.
  • Maintain good control and supervision of contract workers  if applicable.

Supply chain readiness:

  • Check key suppliers are available  and aware of your requirements.
  • Check the state of existing stocks  e.g. condition, use-by dates  (if applicable), etc.
  • Check customer readiness/demand.
  • Check sufficient logistical arrangements are in place for handling incoming and outgoing deliveries.


  • If machinery has been idle, check inspection/maintenance routines to OEM guidelines, consider what is needed prior to restart, lubrication routines, etc.
  • Conduct any cleaning or sanitising processes as necessary.
  • Ensure utilities systems are checked and available, particularly those which may have been isolated.
  • Check all machinery and process safeguards, alarms and interlocks are in service.
  • Follow start-up operating procedures carefully.
  • For complicated production lines this may include a “walk the line” by operating leaders prior to start-up.
  • Give special consideration to equipment with fuel-in-air explosion hazards (fired equipment such as boilers, incinerators, etc.).

Ignition Sources:

  • Use and enforce procedures for hot work, smoking, portable heaters, battery powered appliances, etc.
  • Ensure electrical inspection, testing and maintenance routines are up  to date.

Fire Protection and Emergency Response: 

  • Ensure fire protection systems  and special protection systems  (e.g. smoke detection, fire pumps, sprinkler systems, deluge systems, water spray, etc) are in service, and any remote monitoring systems  are active.
  • Check fire pre-plans are still accurate.
  • Ensure sufficient emergency responders and equipment are available.
  • Alert local fire brigade to planned  restart of activities where appropriate.


  • Ensure all areas are tidy and clear, especially remove unnecessary combustible and waste materials.
  • Conduct a plant visual inspection before start-up, including the buildings, machinery, utilities, storage areas, emergency systems and documentation.
  • Maintain good storage practices during start-up and restocking,  such as clear aisle spaces, avoiding / reducing storage of idle pallets, segregating incompatible materials.

Access and security:

  • Ensure adequate security arrangements are in place  (e.g. fencing, lighting, guard personnel, access controls, etc)  and be extra vigilant during  busy start up periods.
  • Trim and remove foliage that may have grown during idle periods.
  • Ensure yard storage is minimised  and kept clear of buildings.