Sign selection


Sign types

Sign size & viewing distances

The standard BS ISO 3864-1:2011 (that has superseded BS 5499-1:2002) specifies a system of geometric shapes and safety colours for use with the appropriate graphical symbols to produce safety signs. It is applicable to signs that provide information on the actions to be taken to prevent or reduce the risk of accidents, warn of the presence of a potential hazard and for dealing with certain emergencies including the identification of escape routes and the location of fire equipment. The general meanings assigned to geometric shapes, safety colours and contrast colours can be found in the table below :

ColourShape MeaningSymbol ColorExample
Fire fighting equipment White
Public informationWhite
Mandatory White
Emergency escape route White

Safe condition signsWhite

#Sign types

For signs to be seen clearly they must be mounted according to the appropriate viewing angle. 

Type 1 (single-sided)
Parallel wall mounted sign.

Type 2 (double-sided)
A Type 2 sign is mounted perpendicularly to the wall by means of either a rigid aluminium or flexible plastic bracket. The flexible bracket consists of a plastic strip which enables the perpendicular installation of a double-sided Type 2 sign and was developed with the aim of allowing a sign to swing through a 180 radius without breaking if struck. 

Type 3 (double-sided)
A Type 3 suspended double-sided sign is intended to be suspended from a ceiling. The sign is supplied with fixing holes drilled in the top corners to allow the appropriate suspension fixing to be attached. (fixings not supplied)

Type P (panoramic signs)
A panoramic sign offers the greatest visibility and is printed on the two outfacing surfaces to offer a 180 view radius.

#Sign size and viewing distances
The size of the sign is defined by the maximum viewing distance from which the sign is understandable. The table below shows the maximum viewing distance of each sign according to BS 5499-4:2000 for safe condition signs and BS ISO 3864-1:2011 (superceding BS 5499-1:2002) for other signs categories. The viewing distance at which a sign of a particular size is conspicuous and comprehensible depends on the illumination of the sign and the amount of detail it contains.

D - maximum viewing distance in metres (m) 
h - overall height (printed area) of the signboard in millimetres (mm). 
Z - distance factor taking into account the sign category, illlumination factors and level of detail. 

According to BS 5499-4:2000 – escape route signs have a distance factor value (Z) of 170 whereas other sign types have an assumed distance factor value of 60 as defined by BS ISO 3864-1:2011.

 Signs Shape Sign category Z - Distance  h - Sign height mmSign size  D - viewing

 170 80100x100 14
 131 150x15022
 80 200x10014
 180 200x200 31
 278 300x300  47
 376400x400  64
 560600x600 95
 80300x100  14
 129 300x150 22
 78 400x100 13
 98 400x120 17
 129400x150  22
 180400x200 31
 129600x150  22
 180 600x20031 
 276 600x300 47
 176 800x200 30
 276900x300  47
 3641200x400 62
 5201200x600  88
signs or 
60  80100x100  5
 131100x150 8
 180200x200  11
 278300x300  17
 376400x400 23
 56base 100  3
 94base 150 6
 130base 200  8
 193base 300 12
 264base 400 16
 6580x80  4
 80100x100  5
 131150x150  8
 180200x200  11
 278300x300  17
 376400x400  23
  36150x50  2
 36200x50  2
 57200x70 3
 80200x100  5
 129300x70  3
 80 300x100 5
 98300x150  8
 129 400x100 5
 180400x120  6
 129400x150  8
 180400x200  11
 129 600x150 8
 180 600x200 11

The size of the sign is chosen according to the maximum viewing distance and the layout of the premises. 
However, the viewing distance at which a sign of a particular size is conspicuous and comprehensible depends on the sign category, illumination factors and level of detail. 

Viewing distances (according to BS ISO 3864-1: 2011) – Fire equipment and sign categories 
Viewing distances (according to BS 5499-4: 2000) – Escape route signs