ISO Prohibition Signs
Red circular signs with a diagonal bar identify an action that must not be taken in the marked area.
ISO prohibition signs forbid a specific behaviour: smoking, open flames, entry by unauthorised people, using a lift during a fire. They are the most numerous family on this site because they cover everything from industrial plant to beaches, ski slopes, and swimming pools.
Read a prohibition sign literally. It forbids the action shown and nothing else. "No open flame" (P003) is broader than "No smoking" (P002), and "Do not use lift in the event of fire" (P020) does not mean the lift is out of service. A prohibition sign also does not describe the hazard behind the rule, which is why it is often posted beside a warning sign.
Check what object or action the symbol prohibits. A prohibition sign does not identify all the hazards in an area.
No symbols match. Try another word or clear the search.
General prohibition
Smoking, flames and heat
P002No Smoking
P003No open flame; Fire, open ignition source and smoking prohibited
P011Do not extinguish with water
P016Do not spray with water
P039Hot works prohibited
P040Do not set off fireworks
P045No campfire
P068Do not expose to direct sunlight or hot surface
P073Do not shut lid when burners are operating
Access restrictions
P004No thoroughfare
P006No access for forklift trucks and other industrial vehicles
P007No access for people with active implanted cardiac devices
P014No access for people with metallic implants
P021No dogs
P036No children allowed
P042Not for pregnant women
P043Not for people in the state of intoxication
P071Do not cross barrier
P080No access for unauthorized persons
Movement and behaviour
Machinery, tools and equipment
P010Do Not Touch
P012No heavy load
P015No reaching in
P020Do not use lift in the event of fire
P025Do not use this incomplete scaffold
P026Do not use this device in a bathtub, shower or water-filled reservoir
P027Do not use this lift for people
P028Do not wear gloves
P030Do not tie knots in rope
P031Do not alter the state of the switch
P032Do not use for face grinding
P033Do not use for wet grinding
P034Do not use with hand-held grinding machine
P069Not to be serviced by users
P070Do not put finger into the nozzle of a hydromassage
P074Child seat installation prohibited
P075Do not stare at light source
Food, drink and personal devices
Water and beach activities
P049No swimming
P050No snorkelling
P051No sub-aqua diving
P052No diving
P053No sailing
P054No windsurfing
P055No manually powered craft
P056No mechanically powered craft
P057No personal water craft
P058No towed water activity
P059No surf craft
P061No jumping into water
P062No pushing into water
P063No body boarding
P064No surfing between the red-and-yellow flags
P065No kite surfing
P066No parasailing
P067No sand yachting
Snow sports and ride areas
Where prohibition signs come from
ISO 7010 registers the pictograms; ISO 3864-1 sets the colors, shapes, and layout rules they are drawn to. In the EU, Directive 92/58/EEC sets minimum requirements for safety signs at work, and its annex requires the red parts to cover at least 35% of a prohibition sign's area. The UK implements the same requirements through the Health and Safety (Safety Signs and Signals) Regulations 1996, and both markets publish ISO 7010 as EN ISO 7010.
In the United States, OSHA 29 CFR 1910.145 and the ANSI Z535 series govern accident-prevention signs. ISO pictograms are widely used inside ANSI Z535 layouts, but the ANSI format adds signal words and text panels that an ISO sign does not carry. Australia uses AS 1319. Always check the rules for the site where the sign will be installed.
Frequently asked questions
What does a red circle with a line through it mean?
It is an ISO 7010 prohibition sign: the action shown inside the circle is not allowed. The diagonal bar always runs from top left to bottom right and passes over the pictogram. P001, the bar with no pictogram, is the general prohibition and must be explained with text.
What is the difference between "No smoking" and "No open flame"?
P002 forbids smoking only. P003 forbids open flames, fire, open ignition sources, and smoking, so it is the correct sign where any ignition source is dangerous, such as fuel stores or areas with flammable atmospheres.
Can I make my own prohibition sign for a rule that has no ISO symbol?
ISO 3864 sets the design rules for new symbols, but a home-made pictogram may not be understood. Where no registered symbol exists, the usual approach is the general prohibition sign (P001) combined with a clear text panel.
Why are there so many beach and water prohibition signs?
ISO 7010 includes a set of water-safety prohibitions (no swimming, no diving, no jumping into water and others) developed alongside ISO 20712 for water safety signs and beach safety flags, so that beaches and pools in different countries use the same pictograms.