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OHSAS vs. OHSMS: What is the difference

With the release of ISO 45001:2018 some people have become confused with the acronym OHSMS and the acronym OHSAS which was previously used in the title of the occupational health & safety management system standard OHSAS 18001:2007. So, what is the difference between these two acronyms, and what does it mean for occupational health & safety at your company? Find out more about the difference between OHSAS and OHSMS below.

What is OHSAS and where does it come from?

OHSAS is the acronym for Occupational Health and Safety Assessment Series. This refers to the series of standards that were issued by the British Standards Institute (BSI) in 1999, which included 2 standards: OHSAS 18001:1999 and OHSAS 18002:1999.

OHSAS 18001 was a standard that included the requirements for creating an Occupational Health & Safety Management System (OHSMS), while OHSAS 18002 was a supporting standard that gave guidelines for implementation of the OHSAS 18001 standard.

OHSAS 18001 was updated in July 2007, becoming OHSAS 18001:2007. This update was intended to better reflect the guidelines for implementation, and to put greater emphasis on the “health” component of health & safety. This was the standard used by many companies around the world until the International Organization for Standardization released the ISO 45001:2018 standard. For clarity, the OHSAS 18000 standard was published completely outside of the ISO framework by BSI. There is an ISO 18000 standard, but this is a standard for radio-frequency identification.

For a better understanding of the steps to transition from OHSAS 18001 to ISO 45001, see the article: How to make the transition from OHSAS 18001 to ISO 45001.

OHSAS vs OHSMS: What is the difference

OHSMS: What is it?

On the other hand, OHSMS is the acronym for Occupational Health & Safety Management System. The OHSMS are all of the rules, policies, processes and procedures that an organization puts in place to continually improve OH&S performance, fulfil legal and other OH&S requirements and achieve OH&S objectives for the company. These requirements include understanding the hazards and risks of your processes, knowing your legal and other requirements, and identifying and implementing the controls needed to avoid injury and ill health in the workplace.

As mentioned above, the OHSAS 18001:2007 standard was used as the requirements for many OHSMS implementations at many companies throughout the world. Now that ISO 45001:2018 has been released as the internationally recognized requirements for an OHSMS, it is expected to replace the OHSAS 18001:2007 standard in use. Both of these standards included the requirements needed to create an occupational health & safety management system for your organization.

For more information on implementing your OHSMS using ISO 45001:2018, see the article: 12 steps for implementation and certification against ISO 45001.

What does this mean for your organization?

As has been posted by both the international organization for standardization, and the British standards institute, the ISO 45001:2018 standard is intended to replace the OHSAS 18001:2007 standard for use as requirements to create an OHSMS. As such, companies have three years from the release of ISO 45001:2018 to transition their management systems over to the requirements of the new standard; the deadline is March 2021. After this, the OHSAS 18001:2007 standard will be obsolete and any companies still using this standard will not be able to certify their OHSMS.

While many of the requirements are the same in the new standard, there are some new requirements to consider. If your organization has already implemented an OHSMS using the OHSAS 18001 requirements, you need to find out how to comply with any new requirements (such as consultation and participation of workers) and implement these new processes within your organization. It is best to start with a gap analysis against the standard requirements to see what you are missing, such as this free online ISO 45001 Gap Analysis Tool.

If you are implementing a new OHSMS it is important to note that you should not use the OHSAS 18001 standard as it is going out of use. Instead, start with the ISO 45001 requirements and implement the processes needed to meet these requirements from the start; there is no need to start with the older standard and then transition to the new standard.

Implement an OHSMS that will benefit your organization

It doesn’t matter if you are transitioning from OHSAS 18001, or starting to implement an OHSMS from ISO 45001, the important thing to remember is why you are implementing the OHSMS. You need to implement the processes that will help you to improve your OH&S performance and avoid injury and ill health in the workplace. The requirements are there to inform you of the processes that are needed in a world-class management system, but you need to interpret the requirements to work for your organization.

For a better understanding of the OHSMS requirements according to ISO 45001:2018, download this free white paper: Clause-by-clause explanation of ISO 45001:2018.

Advisera Mark Hammar
Mark Hammar
Mark Hammar is a Certified Manager of Quality / Organizational Excellence through the American Society for Quality and has been a Quality Professional since 1994. Mark has experience in auditing, improving processes, and writing procedures for Quality, Environmental, and Occupational Health & Safety Management Systems, and is certified as a Lead Auditor for ISO 9001, AS9100, and ISO 14001.