In brief
Under the Regulation on Health and Safety Signs, each type of sign has a fixed shape and colour: a prohibition sign is a circle with a red border, a warning sign a yellow triangle, a mandatory sign a blue circle, emergency exit and first aid signs are green, and firefighting signs are red rectangles. Signs are chosen according to the risk assessment, placed at eye level in well-lit places, and their meanings are explained to workers through training.
When are workplace safety signs used?
Workplace safety signs are tools that convey a hazard, a prohibition or a behaviour required of the worker at a glance. But a sign is not the measure itself. Under Art. 5 of the Regulation on Health and Safety Signs, the employer uses signs where, as a result of the risk assessment, risks cannot be eliminated or sufficiently reduced by collective protection and work organisation. In other words, hanging a “Caution” sign next to a machine whose guard has been removed does not solve the problem; first the guard is fitted, and the remaining risk is communicated with a sign.
The Regulation applies to all workplaces covered by Law No. 6331. It has two exceptions: labels used in placing dangerous substances on the market, and signs used in road, rail, sea, air and inland waterway transport (Art. 2). Labels on chemical packaging are subject to their own legislation; signs inside the workplace are subject to this Regulation.
A sign is not only a signboard either. The Regulation covers signboards, safety colours, illuminated and acoustic signals, verbal communication and hand signals together. In this article we focus on the most commonly used signboards and colours.
Safety sign colours and their meanings
Annex 1 of the Regulation fixes the meaning of colours for all signs using a safety colour. Using a colour outside its own meaning disrupts workers’ habits and reduces the value of the sign.
| Colour | Meaning | What is expected of the worker |
|---|---|---|
| Red | Prohibition sign | Avoiding dangerous actions or behaviour |
| Red | Danger alarm | Stop, shut down, emergency stop the device, evacuate |
| Red | Firefighting equipment | Seeing and recognising where the equipment is |
| Yellow | Warning sign | Be careful, take precautions, check |
| Blue | Mandatory sign | Specific behaviour or action; for example, wear PPE |
| Green | Emergency exit and first aid | Doors, exits, routes, equipment and facilities |
| Green | No danger | Return to normal |
Two details are often missed. First, blue counts as a safety colour only when used inside a circular sign; a blue information board does not carry a mandatory meaning. Second, fluorescent orange may be used instead of yellow outside safety signs and is particularly eye-catching in conditions of poor natural visibility.
Prohibition, warning and mandatory signs: shape rules
Annex 2 of the Regulation sets out the shape, background and colour proportion for each type of sign. The colour proportion is the rule that makes the sign recognisable from a distance.
| Type | Shape | Background and pictogram | Colour proportion |
|---|---|---|---|
| Prohibition sign | Circle | White background, black pictogram, red border and diagonal bar | Red at least 35% |
| Warning sign | Triangle | Yellow background, black pictogram, black border | Yellow at least 50% |
| Mandatory sign | Circle | Blue background, white pictogram | Blue at least 50% |
| Emergency exit and first aid sign | Rectangle or square | Green background, white pictogram | Green at least 50% |
| Firefighting sign | Rectangle or square | Red background, white pictogram | Red at least 50% |
Prohibition signs
These prohibit a behaviour: no smoking, smoking and naked flames prohibited, no access for pedestrians, do not extinguish with water, not drinkable, no access for unauthorised persons, no access for industrial vehicles, do not touch. The entrances to paint and solvent stores, electrical switch rooms and forklift aisles are the most typical places of use.
Warning signs
These indicate the presence of a hazard: flammable material or high temperature, explosive material, toxic material, corrosive material, radioactive material, overhead load, industrial vehicles, electrical danger, laser beam, oxidising material, non-ionising radiation, strong magnetic field, obstacles, drop, biological risk, low temperature, and harmful or irritant material. Not using the general “Danger” sign when a more specific pictogram exists makes the message clearer.
Mandatory signs
These say what must be done: wear eye protection, wear a safety helmet, wear gloves, wear a mask, wear safety footwear, use the pedestrian route, wear protective clothing, wear a face shield, wear a safety harness, wear hearing protection. A mandatory sign must correspond exactly to the PPE identified in the risk assessment. If the sign says “wear hearing protection”, hearing protection must have been distributed in that area, its use explained and its use monitored. For obligations on the PPE side, see our article on the PPE Use Regulation.
Emergency exit, first aid and fire signs
Green signs show the emergency exit and escape route, directions, the first aid point, stretcher, safety shower, eye wash and emergency telephone. Red rectangular signs indicate the location of fire hoses, fire ladders, fire extinguishers and the emergency fire telephone. The place where firefighting equipment is located is also permanently marked in red next to the signboard. For types of extinguisher, see our fire extinguisher guide.
Floor, obstacle and pipe marking
Floor and equipment marking is inspected just as much as signboards. The annexes to the Regulation set the following rules:
- Obstacles and dangerous locations: Places with a risk of collision, falling or falling objects are marked with yellow-and-black or red-and-white stripes. The stripes are painted at an angle of about 45 degrees and of equal width; their size is proportional to the size of the obstacle (Annex 5).
- Traffic routes: Routes open to vehicle traffic are marked with continuous yellow or white stripes, taking the floor colour into account. The stripes should show a safe distance between vehicles and pedestrians. We explained how to apply this rule in warehouse and dispatch areas in our article on the forklift and pedestrian traffic plan.
- Pipes and containers: Visible pipes and containers carrying dangerous substances are marked with labels; the label may be replaced by a warning sign bearing the same pictogram. Pipes, valves and fittings containing dangerous substances are painted in different colours according to the substance they carry (Annex 3).
- Stores: Areas where significant quantities of dangerous substances are stored are indicated with a suitable warning sign if the packaging labels are not sufficient; the sign is placed at the store entrance.
Placement and maintenance of signs
Even the right sign is useless in the wrong place. The placement rules in Annexes 1 and 2 can be summarised as follows:
- Location: If there is a specific hazard, the sign is placed right next to the hazard; if there is a general hazard, at the entrance to the area.
- Height and visibility: Taking obstructions into account, the sign is placed at a height suited to eye level, at a well-lit and easily accessible point.
- Poor light: In places with insufficient natural light, fluorescent colours, reflective materials or artificial lighting are used.
- Avoiding clutter: Many signs are not placed too close together. Ten signs in a row means ten signs no one reads.
- Material: The sign is made of material suited to the environment and resistant to impact and weather.
- Being up to date: When the situation a sign indicates no longer exists, the sign is removed too. A warning sign left at the old location of a machine that has been moved reduces the credibility of the other signs.
- Maintenance: Signs are cleaned, checked, repaired and replaced where necessary at regular intervals. Signs that require power must work immediately from a backup source when the power is cut.
Where do workers learn about signs?
A sign works if the worker knows what it means. The Regulation therefore imposes two obligations: the employer informs workers or their representatives about the signs used at the workplace (Art. 6/1) and ensures that workers receive training on the meaning of the signs and the behaviour they require (Art. 6/2). In addition, workers are consulted and involved on matters covered by the Regulation (Art. 7).
In practice, the most effective way is to show the signs on the spot during the site tour in induction training. A new worker learns on their first day by seeing the pedestrian walkway in the main aisle, the green direction arrows pointing to the assembly area and the mandatory signs in their department. You can add this step to the example flow in our article on the induction training programme. In workplaces with foreign workers, it is also important to explain the meaning of pictograms in a language they understand, because the Regulation requires that even in verbal communication the language used is understood.
Common mistakes are: PPE not being distributed in an area where a mandatory sign is posted, emergency exit arrows leading to a locked door, material stacked in front of a fire cabinet making the red sign invisible, and more signs than necessary in one area. Our recommendation for businesses in Bursa and neighbouring provinces is to look at these four points in particular on site rounds; all of them can be corrected quickly.
Within OHS training, we explain the meaning of signs in a practical way, and in our OHS specialist service, we keep the sign plan up to date together with the risk assessment. For warehouse and dispatch areas, see also our logistics and warehousing sector page.
Frequently Asked Questions
Does every blue sign indicate an obligation?
No. Under the Regulation, blue counts as a safety colour and carries a mandatory meaning only when used inside a circular sign. A square or rectangular blue board is for information.
How can a prohibition sign be told apart from a warning sign?
A prohibition sign is a circle with a red border and diagonal bar on a white background; it prohibits a behaviour. A warning sign is a triangle with a yellow background and black border; it indicates the presence of a hazard.
Must signs be explained to workers in training?
Yes. Under Art. 6 of the Regulation, the employer both provides information about the signs and ensures that workers receive training on the meaning of the signs and the behaviour they require. You should be able to show this in your induction and basic training records.
Does the label on chemical packaging replace a store sign?
If the packaging label is sufficient to communicate the precautions in the storage area, a separate sign may not be needed. If it is not, a suitable warning sign is placed at the store entrance; where different dangerous substances are stored together, a general danger warning may be used.
Induction, basic and refresher training in line with the 2026 regulation; on your premises, with examples from your own site and fully documented.
Bursa SİSTEMER OSGB Technical Team — written from the field experience of our OHS specialists and workplace physicians. Legal information is valid as of the publication/update date; contact us for an assessment specific to your business.