Process Safety · Explainer
Management of change: why small changes deserve a structured pause
A substitute gasket, a new setpoint, a revised procedure: most changes are routine. Management of change is for the ones that are not.
Process plants change constantly: equipment is modified, materials are substituted, operating limits are adjusted, procedures are rewritten and staff move on. Each change can alter the hazards that the original design and hazard analysis assumed.
What the US PSM standard requires
For processes covered by OSHA’s PSM standard, 29 CFR 1910.119(l) requires written procedures to manage changes. Except replacements in kind. To process chemicals, technology, equipment and procedures, and changes to facilities that affect a covered process [1]. Before any change, the procedures must address:
- the technical basis for the proposed change;
- the impact of the change on safety and health;
- modifications to operating procedures;
- the necessary time period for the change; and
- authorisation requirements for the proposed change [1].
Affected operating, maintenance and contract employees must be informed of and trained in the change before start-up, and process safety information and operating procedures must be updated where the change affects them [1].
The link to pre-startup safety review
Paragraph (i) of the same standard requires a pre-startup safety review for new facilities and for modified facilities when the modification is significant enough to require a change in process safety information. Among other things, it confirms that construction and equipment match design specifications and that procedures and training are in place [1].
Where management of change is tested
The difficult part is rarely the form. It is recognising that something is a change at all. “Replacement in kind” means an exact like-for-like replacement that satisfies the design specification; anything else deserves the question.
A pump seal is out of stock, and stores offer a different model “that fits”. It may have a different pressure rating or material compatibility. Treating this as a change. Checking the specification before installing it. Is exactly the pause management of change is designed to create.
Questions to ask
- Is this an exact replacement in kind? If not sure, treat it as a change.
- Does it affect hazard analysis assumptions, relief sizing, alarms or interlocks?
- Is it temporary? If so, who removes it, and when?
- Who needs to know and be trained before it goes live?
Organisational changes. Reduced staffing, a new contractor, a merged role. Can affect process safety as much as hardware changes. OSHA has also addressed management of organisational change in interpretation letters; check current guidance for your situation.
General educational material, not legal advice, a site-specific risk assessment or a work authorisation. Confirm current requirements in your jurisdiction and follow site procedures and competent advice.
References
- OSHA. 29 CFR 1910.119, paragraphs (i) and (l)United States
- OSHA. Interpretation: Management of Organizational Change (31 March 2009)United States
All sources opened and checked on 30 October 2026. Requirements and guidance change; always consult the current version.
Editorial status: source-checked explainer. No independent external technical review is claimed. Spotted an error? See corrections.
