ISO 7010:2019 / ISO 3864-1
ISO P023 Do not obstruct Sign
ISO P023 Do not obstruct Sign means the marked zone must be kept permanently clear, with nothing parked, stored, stacked, or left in it at any time, because a fire door, escape route, piece of emergency equipment, or electrical working space lies behind it. It should be used where the cited standard, facility risk assessment, SDS, emergency plan, or written safety procedure requires this hazard or safety message to be communicated.
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Reference artwork: Wikimedia Commons · License: Public domain
Technical Data
| Legal Standard | ISO 7010:2019 / ISO 3864-1 |
|---|---|
| Color Codes | #FF0000 / Closest practical match: RAL 3020 Traffic Red |
| Viewing Distance | 50 mm: close equipment or package label; 100 mm: approximately 5 m; 200 mm: approximately 10 m; 300 mm: approximately 15 m; 400 mm: approximately 20 m. |
| Review Status | approved / last reviewed 2026-07-07 |
| Jurisdiction Scope | Global, United States, European Union |
| Keywords | p023, iso 7010, prohibition, not, obstruct, prohibit, obstruction, designated, clear, area |
Standard Dimensions Table
| Sign Size | Recommended Visibility |
|---|---|
50 mm | close equipment or package label |
100 mm | approximately 5 m |
200 mm | approximately 10 m |
300 mm | approximately 15 m |
400 mm | approximately 20 m. |
Where This Sign Is Used
It polices exit routes, final exits, and corridor pinch points under rules like OSHA 1910.37, guards access to extinguishers, hose reels, alarm call points, and sprinkler valves, and preserves the working clearance in front of electrical panels and switchgear. Loading docks, roller shutter doors, machine hatches, and emergency vehicle lanes carry it too, usually above a hatched floor box marking the exact footprint.
In-Depth Guidance
Keeping Designated Areas Clear
P023 prohibits obstructing a designated clear area. Where most prohibition signs govern a moment of behavior, this one governs a state: nothing may be parked, stored, stacked, or left in the marked zone at any time. The pictogram — a crossed-out obstacle blocking a space — is deliberately generic because the protected asset behind it varies from a fire door to a switchboard.
The sign matters because obstruction is the quietest way a safety system fails. A pallet set down in front of a hose reel for just an hour, a delivery cage rolled against a fire exit, chairs drifted into an escape corridor — none of it looks like a violation until the emergency arrives and the equipment or route cannot be reached. P023 converts an invisible rule into a visible boundary.
What the Clear Zones Protect
Escape routes and exits are the classic application. OSHA's exit-route rule, 29 CFR 1910.37, requires routes to remain free of obstructions and unlocked in the direction of travel, and European workplace regulations impose the same duty; P023 on and around fire doors, final exits, and corridor pinch points is how facilities police it day to day. Fire equipment comes next: extinguishers, hose reels, alarm call points, sprinkler valves, and hydrants all lose their value if reaching them takes minutes.
Electrical installations form the third pillar. Electrical codes require a clear working space in front of panels and switchgear — under the US National Electrical Code this is generally around three feet deep — so that equipment can be operated and de-energized safely in an emergency. Loading areas add their own cases: roller shutter doors, dock levelers, machine access hatches, and emergency vehicle lanes outside the building.
Making the Prohibition Stick
P023 works far better as the label on a marked zone than as a lone plaque. The standard pattern is a hatched yellow-and-black or red floor box painted or taped to the exact footprint that must stay empty, with the sign at eye level on the wall or door behind it. Storage crews respect an outlined rectangle they can see from a forklift seat much more reliably than a sign at head height they pass at speed.
Enforcement is a housekeeping discipline, so build the zones into inspection checklists and give supervisors authority to have items moved immediately rather than logged for later. Where the same spot is blocked repeatedly, treat it as a layout problem: the aisle is too narrow, the staging area too small, or the bin in the wrong place. Signage cannot outargue a workflow that has nowhere else to put things.
Frequently Asked Questions
What is the ISO P023 do not obstruct sign used for?
It marks zones that must stay permanently clear: in front of fire exits and fire doors, around extinguishers, hose reels, and alarm call points, before electrical panels and switchgear, at roller shutters and dock doors, and along emergency access lanes. Anything stored or parked there — even briefly — defeats equipment or routes that only matter in an emergency.
How much space must be kept clear in front of an electrical panel?
Electrical codes define a required working space so panels can be operated and maintained safely; in the US the National Electrical Code generally calls for a clearance on the order of three feet in front of the equipment, with the full width of the panel or more kept open. Requirements vary by voltage and configuration, so confirm the figure for your installation and mark that footprint on the floor with P023 above it.
Is blocking a fire exit actually illegal?
Yes, in essentially every jurisdiction. OSHA 1910.37 requires exit routes to be kept free of obstructions in US workplaces, and fire safety legislation in the UK, EU, and elsewhere places the same duty on whoever controls the premises. Inspectors treat blocked exits as a serious finding because the obstruction removes the escape route precisely when it is needed.
Should do-not-obstruct areas be marked on the floor as well as signed?
Strongly recommended. A hatched floor box showing the exact keep-clear footprint communicates the rule to forklift drivers and staff carrying loads who never look up at wall signs, and it removes arguments about how close is too close. The P023 sign then explains what the marking means and signals that the zone is a safety requirement, not a suggestion.