It was the third annual event the branches -- Manchester and North West Districts, Merseyside and North Wales -- have put on together. The Institute of Directors' North West Region also took part in the planning.
Expert speakers looked into what should happen after a hypothetical serious incident. It also showcased the importance of businesses having robust occupational safety and health management systems in place to avoid such incidents.
Topics covered included root cause analysis and recording lessons learned to ensure that such an incident does not happen again.
The event, held at Widnes Rugby Football Club on Wednesday 8 June, was aimed at IOSH members and other senior business leaders.
David Collins, chair of IOSH's Merseyside branch, said: "In our profession we work hard to ensure that safe and healthy management systems are in place in organisations to prevent anyone getting harmed.
"However it is also important that people know what procedures should be followed when something happens. That is what this event explored. It was relevant for both safety and health professionals and for other business leaders who want to find out more about how they should handle such an occurrence."
Rachel Jones, North Wales branch chair, said: "We were very pleased to once again bring our branches together for this event.
"Businesses are increasingly viewing safety and health as being vital to what they do and we hope they were able to take away some valuable information from our event."
Fiona Riley, chair of the Manchester and North-West Districts Branch, added: "Once again we had an excellent event which was very well attended. All three branches put a lot of work into it and we had some very good speakers."