HSG253
HSG253: the safe isolation of plant and equipment
Updated 2026
HSG253 is HSE guidance on the safe isolation of plant and equipment, ensuring machinery is positively isolated from all energy sources before maintenance. While HSG253 focuses on isolation procedures, knowing who is inside an isolated area, in real time, is a valuable additional control that supports permit-to-work and prevents re-energising equipment while people are still present.
- 1. HSE
- 2. HSE, HSG250
- 3. Industry standard
What HSG253 addresses
HSG253 sets out principles for the safe isolation of plant and equipment across the process industries. Positive isolation, proving isolation and secure lock-off are central themes.
It is closely linked to permit-to-work systems, which control high-risk activities and coordinate the people involved.
Personnel awareness as an added control
A recurring cause of serious incidents is re-energising equipment while a worker is still inside a machine or vessel. Zone awareness, knowing in real time whether anyone remains inside an isolated area, provides an independent check before energy is restored.
Integrated with permit-to-work, this gives supervisors confidence that the area is clear, complementing the physical lock-off that HSG253 describes.
Robin Hind
Managing Director, Res.Digital
Robin Hind is Managing Director of Res.Digital, the technology company behind The Salvus Network. He leads the team building the platform and works directly with the industrial, construction and high-risk sites that use it to account for their people, assets and emergency response in real time.
Connect on LinkedInFrequently asked questions
Is personnel tracking a substitute for lock-off?+
No. Physical isolation and lock-off remain the primary control. Real-time zone awareness is an additional layer that helps confirm an area is clear before equipment is re-energised.
Book a live evacuation demo
A guided live walk-through of what the platform can do.