“A heavy metal-free tanning has certainly a low environmental impact, with high biodegradability features, and is ideal for creating items for people allergic to chromium and other metals”, explains Enrico Gastaldello, general manager of SYN-BIOS. To make metal free leathers, carrying out the tanning process without the use of metals is however not enough. Also the choice of the finishing products and the dyes used, which in turn must be metal free, is very important.
For this purpose, SYN-BIOS Spa has developed a new range of micro-dispersed pigments in aqueous system (called METAL-FREE®), specially selected to create metal-free leathers also in the finishing phase, in compliance with the standard UNI EN 15987:2015 ["Animal skin converted into leather, whose total content of all tanning metals in leather (Cr, Al, Ti, Zr, Fe) is less than or equal to 0.1% (mass of the sum of all metals/total dry weight of leather)"].

Enrico Gastaldello, general manager of SYN-BIOS SpA

“The shades of the METAL-FREE® series cover the entire colour range, ensuring maximum yield and an optimal degree of coverage. The range also guarantees the best chemical-physical solidities in order to obtain an item intended for the leather goods, footwear, furniture and automotive sector”, explains the Venetian chemical tanning company.
The METAL-FREE® series developed by SYN-BIOS, beyond respecting all the limits of the MRSL v.2.0 of ZDHC, is also structured in such a way as to allow the use of all colours, alone or in combination, without exceeding in the finished item the concentration by 0.1% of the sum of the five tanning metals.