Path Length: 40mm

The EP Colour Standards were originally visual colour standards intended to improve colour communication between sites by defining a sample colour as being close to a physical liquid standard ("near EP Y2") rather than using the words "light yellow".

EP consists of 3 primary colour standard solutions (yellow, red, blue) that are combined with hydrochloric acid to make 5 standard solutions that when further diluted with hydrochloric acid (10 mg/l) make 37 reference EP standards; Red (R1 - R7); Yellow (Y1 - Y7); Brown (B1 - B9); Brown/Yellow (BY1 - BY7); Green/Yellow (GY1 - GY7).

The procedure for manufacturing these standards is time consuming and tedious and the stock solutions must be stored in a cool dark place in order to remain colour constant. It is for these reasons that standards of a more stable nature were  in demand. Thus a series of  Lovibond® colour discs were originally developed to represent this scale.

An alternative to the visual methods is now available as a program in the Lovibond® PFX and PFXi ranges of spectrocolorimeters. Measurements are based on a comparison of CIEL*a*b* values for the samples to saved values for the EP standards (US and Chinese Pharmacopoeia are local alternatives.)

AF332 EP Colour Scale (Ph Eur Method 2.2.2) AF332 EP Colour Scale (Ph Eur Method 2.2.2)
PFX<i>i</i>-195/5 PFXi-195/5
606890 606890 40 mm path length calibrated at 20ml Series Fused Optical Glass