There are currently two test methods for Chromium VI used within the leather industry: DIN 53314 (technically the same as IUC 18: 1997) and EN TS 14495:2003 (technically the same as IUC 18: 2003). Both methods are based upon the colorimetric determination of CrVI.
There are two key differences between the methods. The more recent EN TS 14495 employs the use of solid phase extraction to remove any interfering dyestuffs (which can cause inconsistencies in the results under the DIN method). Secondly, the detection limits, which are as follows: DIN 53314 is 3ppm and EN TS 14495 is 10 ppm.
Currently any leather that is intended for sale in Germany needs to comply with a 3ppm detection limit, and so should be tested according to DIN 53314.
However, it is recognised by the CEN leather chemical testing committee (CEN TC289 WG1) that the method EN TS 14495 is the best available for the leather industry. For this reason the committee is currently arranging for this method to become a full CEN standard. This process is expected to be completed by the end of 2005 at which time DIN 53314 will have to be withdrawn.
In the interim, BLC will take the approach that testing will be carried out according to DIN 53314 unless otherwise requested.
Where an interfering dyestuff is present, BLC will revert to the EN TS 14495 method of determining Chrome VI, which will give accurate results, and we will advise of this change in the test report.
BLC recommends that any leather/leather product specifications are updated in line with the above. This will be revised upon the EN TS 14495 method becoming a full CEN standard.
For further information please contact Karen Short on karen@blcleathertech.com or +44 1604 679967 or Rachel Garwood on rachel@blcleathertech.com or +44 1604 679935
