Formaldehyde questions answered in Inescop Oxatan project
10/04/2013
With funding from the European Commission, the project, called Oxatan, was able to address these questions. Technical meetings to discuss “the formaldehyde problem” were an early component of Oxatan.
Early in the project, Inescop and its partners carried out physical and chemical tests to determine the presence of any harmful substances in finished footwear and upholstery products made using oxazolidine-tanned leather. Initially, the results obtained proved compliance with EU requirements, except for formaldehyde content.
The project proposal submitted to the European Commission in 2010 established a limit of 150 ppm for formaldehyde and these first tests showed values in excess of this.
At a technical meeting in Pisa in July 2010, Inescop and Italian consultancy CGS came up with two new procedures to solve the problem. They used formaldehyde-free syntans and vegetable tanning agents with the oxazolidine-based tanning system. In addition, they decided to add amine products to react with any free formaldehyde present in the leather to yield a stable compound (oxime) that would be removed during washing.
Inescop said later that adding 2% hydroxylamine sulphate in the final washing of leather yielded finished leather with a formaldehyde content lower than 50 ppm, well below the established limit.
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