# Regulation (EC) No 648/2004 of the European Parliament and of the Council of 31 March 2004 on detergents (Text with EEA relevance), Division 3.4: Calculation of results

Extent: E+W+S+N.I.

Every non-ionic surfactant has its own factor, depending on its composition, particularly on the length of the alkene oxide chain. The concentration of non-ionic surfactant is expressed in relation to a standard substance — a nonyl phenol with ten ethylene oxide units (NP 10) — for which the conversion factor is 0,054.
Using this factor the amount of surfactant present in the sample is found expressed as mg of NP 10 equivalent, as follows:
(b — c) xfx 0,054 = mg non-ionic surfactant as NP 10
where:
bvolume of ‘carbate solution’ used by the sample (ml),
cvolume of ‘carbate solution’ used by the blank (ml),
ffactor of the ‘carbate solution’.

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Source: https://www.legislation.gov.uk/eur/2004/648/annex/VIII/division/3/division/3.4 (the official version)
Page: https://openlegislation.uk/eu-regulation-2004-648/annex-VIII/division-3/division-3.4
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.