Changes to chrome VI test methods19 May 2005
The BLC advise that changes are being made to the way in which leathers are tested for hexavalent chrome. 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 on the colorimetric determination of Chrome VI. 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 3ppm EN TS 14495 10ppm 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 This process is expected to be completed by the end of 2005 at which time DIN 53314 will have to be withdrawn.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 will advise of this change in the test report. BLC recommends that any leather or leather product specifications are updated in line with this. This will be revised upon the EN TS 14495 method becoming a full CEN standard.