This International Standard specifies a method for the determination of the light transmittance of the toluene
extract from carbon black for use in the rubber industry, as a means of measuring the discolouration caused
by the extractable matter
The light transmittance value provides an estimate of the degree of discolouration caused by the toluene-
extractable matter present on the surface of the carbon black.
This method may not be applicable to carbon blacks with a high extractable-matter content.