Traditionally permit to work systems were used in high hazard environments such as oil refineries as part of the overall “safe system of work” (SSOW) to control maintenance type activities. Permit to work systems generally encompass a range of permits with different functions.
They include, but are not limited to.
- An access permit. This document permits access to a specific high hazard area with the permission of the area responsible person.
- Permit to work. Permits certain work activities, but limits the activity and location of work e.g. removal of a specified valve within a specified time period.
- Hot work permit. This can have 2 functions. Firstly to control heat generating equipment that can cause a fire. Secondly to control the risk of explosion from electrical equipment in areas where there is a foreseeable risk that a flammable vapour could be present.
- Isolation certificates (sometimes called lock out – tag out (LOTO)). Issued to control the isolation of equipment undergoing maintenance particularly when the power control point and equipment are in separate locations and the equipment could be inadvertently restarted with severe consequences.
The University operates 2 complimentary permit systems. One issued and managed by Estates and Facilities (EAF); the second operated by Schools for Laboratories and Workshops. The permits form part of the overall safe system of work which can include method statements, risk assessments, site supervision, contractor competency assessment programmes.
|Laboratory and Workshop permit issued by School||Permit issued by EAF|
|Work on School system by external contractor e.g. servicing recirculating local exhaust ventilation system in a laboratory.||√||X|
|Work on building system not impacting school high hazard area organised by EAF.||X||√|
|Work on building system impacting school high hazard area e.g. work on biological safety cabinet (ducted system) by EAF.||√||√|
|Low hazard work organised by School.||X||X|
|Low hazard work organised by EAF||X||X|
HSE reference is from the high hazard industrial sector e.g. chemical manufacture. Some of the background information is relevant to lower hazard environments.
Generally there is no explicit legal requirement to operate a permit to work system, but it is the most common way that industry, including low hazard environments, adopts to manage maintenance type activities.