Prohibition signs specify behaviour or actions which are not permitted, a prohibition sign is a safety sign prohibiting behaviour likely to cause a risk to health and safety.
Prohibition signs have a designated symbolic shape in a red circle with a diagonal red slash through it. This is usually superimposed over a black pictograph, for example a cigarette on a no smoking sign, to indicate what specific activity is referred to.
Prohibition Sign wording, if necessary, is in black lettering on a white background.
Prohibition Safety Signs are made in Australia by Industroquip in Polypropylene, Colorbond (Steel), Corflute or even self adhesive vinyl with a heavy duty laminate for extra protection.
The Australian Standard covering safety signs is AS1319-1994. This standard sets out requirements for the design and use of safety signs intended for use in work environments. The aim is to regulate and control safety related behaviour, to warn of hazards and to provide emergency information, including fire protection information. It specifies several sign classifications and layouts.
AS1319 does not specify a required material or nominal size for a safety sign but does stress that the type of safety sign used should be suitable for the intended application, and that employees should be informed of their purpose.
In locations where lighting is good and a safety sign is mounted in a reasonably prominent position, it is recommended that any symbols be at least 15mm per metre of viewing distance, and any uppercase text be at least 5mm per metre of viewing distance. This should be increased by at least 50% for poor lighting or viewing conditions. Where practical, safety signs should be mounted close to the observer's line of sight in the vertical plane.
Safety signs should be located against a contrasting background, and such that the possibility of it becoming obscured by stacked materials or other visual obstructions is minimised.
For maximum effectiveness, safety signs should be maintained in good condition, kept clean and well illuminated.