Do Not Switch Sign

Do Not Switch Sign

Operating the wrong switch, breaker or valve control at the wrong moment can energise equipment being serviced, restart machinery mid-repair, or defeat an isolation that another crew member is relying on for their own safety. A do not switch sign is fitted directly at a switch, isolator, breaker panel or control point to warn that operating it is forbidden until the associated work, isolation or lockout has been formally cleared, protecting anyone currently working on the isolated circuit or system.

Built to the ISO 7010 prohibition format, this do not switch sign uses a red circular band and diagonal bar over a black pictogram of a switch or control lever, presented on a white background. Because the symbol carries the entire instruction, a do not switch sign is understood immediately by electricians, engineers and deck officers alike, regardless of first language, which matters on multinational crews working through a shared permit-to-work system.

Where This Prohibition Sign Belongs Onboard

Typical placements include main switchboard breakers, isolator handles on pumps and motors, control panel switches for machinery under maintenance, and valve actuators forming part of a system that has been deliberately taken out of service. AS 1319 requires prohibition signage to be fixed at the precise point where the restricted action would be taken, so a do not switch sign should be attached directly to the switch or control itself, ideally alongside a physical lockout device, rather than posted nearby on a wall.

Safety Sign Hub manufactures this do not switch sign in a fire-retardant photoluminescent material that charges under normal lighting and glows for hours during a power failure. That property is particularly relevant here, since a do not switch sign is often needed in exactly the low-light conditions created by a partial blackout, where a crew member restoring power elsewhere could otherwise reach for the wrong breaker without a visible warning in place.

Ordering by IMPA and ISSA Code

Ship chandlers and electrical contractors typically order this signage against IMPA code 33.8553 or ISSA code 47.585.53, ensuring the correct pictogram and format are supplied when restocking a vessel’s electrical safety and lockout-tagout signage during survey or dry dock. Referencing the code lets a superintendent standardise this do not switch sign across an entire fleet from a single catalogue reference.

Safety Sign Hub supplies this do not switch sign to Australian-flagged vessels, marine electrical contractors, shipyards and industrial sites running formal lockout-tagout programs. For background on how ISO 7010 prohibition pictograms are structured internationally, see the ISO 7010 standard overview. A clearly fixed, photoluminescent do not switch sign reinforces the vessel’s isolation procedures with a visible, standards-based warning at the exact control point involved.

Electricians and engineering officers issuing an isolation certificate should attach a temporary do not switch sign at the same moment a lock or tag is applied, and remove it only once the certificate is formally closed and the equipment is confirmed safe to re-energise. Keeping a stock of both durable and disposable tag-style formats aboard means the correct warning is always available the moment an isolation is required, day or night, without waiting on shore-based resupply.

Handover between watches is one of the most common points at which an isolation is accidentally defeated, since an oncoming engineer may not yet know that a particular breaker has been deliberately left open. Recording the location of every active warning in the engine room log, alongside the isolation certificate number, gives the next watchkeeper a clear cross-reference and reduces reliance on memory alone during a busy shift change on a working vessel.

Browse our full range of prohibition signs for more IMO-compliant maritime safety signage.