No Unauthorised Entry Sign

No Unauthorised Entry Sign

A no unauthorised entry sign marks a compartment or work area where entry is reserved strictly for personnel who have been specifically authorised, rather than crew or contractors generally. Where an authorised-personnel pictogram implies a defined group may enter, this sign is typically used for higher-risk spaces such as high-voltage rooms, confined tanks, hazardous cargo holds or areas under active maintenance, where even briefly unauthorised entry carries a meaningful safety risk that operators want to head off before it happens.

Built to ISO 7010 pictogram conventions, the no unauthorised entry sign uses the standard black symbol inside a red circle and diagonal bar on a white background, giving a clear, language-independent prohibition message. Stocked under IMPA code 33.8544 and ISSA code 47.585.44, this sign can be ordered quickly by ship chandlers and vessel operators restocking safety signage during a port call, survey preparation or scheduled maintenance period.

Typical uses aboard ship and in port facilities

A no unauthorised entry sign is commonly fitted at hazardous cargo holds, high-voltage switchrooms, tank entry points, and spaces isolated for maintenance where a permit-to-work or isolation procedure is in force. In these situations the sign works alongside physical barriers, lockout tags and permit documentation rather than replacing them, giving anyone approaching an immediate visual cue before they reach whatever additional controls are in place. Port terminals and shore-based plant areas use the same pictogram at fuel lines, electrical yards and equipment under isolation for the same reason: a consistent, recognisable sign reduces the chance of confusion during a busy shift change or when contractors unfamiliar with the site are working nearby.

Every no unauthorised entry sign supplied by Safety Sign Hub is produced in a fire-retardant, photoluminescent material, so it remains visible during a power outage or in smoke-affected conditions, which matters most in exactly the high-risk spaces this sign is used to protect. The substrate also resists the corrosion, humidity and temperature extremes typical of marine and port environments, so a sign fitted at a tank hatch or switchroom door keeps its legibility over years of service rather than fading after a single voyage or wet season.

Safety Sign Hub stocks this no unauthorised entry sign in standard marine signage sizes, with self-adhesive and rigid panel formats available for different mounting surfaces. A self-adhesive version suits a smooth internal door, while a rigid panel with fixing holes is generally preferred for tank hatches, external switchroom doors or other positions exposed to weather and repeated contact. Ordering against the exact IMPA and ISSA codes on this listing avoids the risk of receiving a similarly worded but differently designed pictogram from a supplier working from a generic description rather than a matched reference number.

Aligning with recognised safety signage practice

Using a no unauthorised entry sign at every space requiring specific authorisation reflects the pictogram conventions of ISO 7010, which underpins AS 1319, Australia’s safety signage standard. Reordering the same IMPA and ISSA coded sign across a fleet or facility keeps hazard communication consistent between vessels and shore sites, so crew and contractors recognise the pictogram immediately wherever they encounter it, rather than needing to interpret an unfamiliar design each time they move between ships or work locations.

This sign is also a practical addition to a permit-to-work pack or isolation kit, since it can be produced in a smaller tag-style format for temporary use alongside larger fixed panels for permanent hazard points. A vessel that regularly isolates equipment for maintenance, gas-frees a tank, or restricts a cargo hold during loading benefits from holding a small stock of this pictogram in more than one size, so the correct format is always on hand rather than needing to be sourced at short notice. Keeping the same design across every format also means crew recognise the pictogram instantly, whether it appears as a large fixed sign on a switchroom door or a smaller tag clipped to an isolation point.

Position this no unauthorised entry sign at secured doors and gangways to reinforce ship security procedures against unauthorised boarding. Browse our full range of Prohibition Signs for more IMO-compliant maritime safety signage.