Front Lit and Back Lit Safety Signs
These Front Lit and Back Lit Signs in the Workplace must be durable, securely fastened and properly maintained to ensure they are in place and can be seen easily for as long they are needed.
Front Lit Signs
Signboards are lit from the front and must be sufficiently large and clear so that they can be seen easily when clean. They include prohibitory, warning, mandatory, emergency escape, first aid or fire safety signs. In conditions of poor lighting it will be necessary to improve visibility of the sign, for example by spotlighting the sign and/or using a reflective material.
Labels must be as prominent as possible. In outdoor or other locations exposed to adverse environmental conditions labels may need to be replaced regularly due to fading or the like.
Back Lit Signs
Illuminated signs are those with a light source inside or behind the device. These signs must be sufficiently large and clear so that they can be seen easily when clean. They include all the types which might otherwise be displayed as signboards (front lit signs), but can also include rotating lights used as warning devices on vehicles or plant, control lights where traffic routes cross, supplements to acoustic fire alarms, and the like. The light emitted by an illuminated sign must produce a luminous contrast which:
- shows clearly the colour and, where appropriate, the pictogram;
- does not dazzle the viewer making it hard to see the surroundings.
If the device can emit both continuous and intermittent signs, the intermittent sign should be used to indicate a higher level of danger or a more urgent need for action than the continuous sign.
Flashing signs for use when grave danger arises must be under special surveillance or fitted with an auxiliary lamp.