UPC develops method for detecting toxic substances in leather and footwear
The system improves detection of dimethyl fumarate, a chemical banned in the EU that causes allergies
Researchers at Igualada School of Engineering (EEI), a school associated with the Universitat Politècnica de Catalunya (UPC), have developed a new analytical method that improves detection of dimethyl fumarate (DMFu) in leather and footwear.
The use of DMFu in consumer products is prohibited in the European Union as it causes allergic contact dermatitis. It has been detected in leather products made in Asia, including footwear and sofas. These products are monitored at the EEI by the Catalan Consumer Agency and other organizations and companies, following a method that enables the substance to be detected faster without destroying the sample.
This method, designed by researchers from the EEI, is based on detection using the headspace solid-phase micro extraction (HS-SPME) technique. Unlike more widespread methods of sample preparation, HS-SPME obtains samples from the product without damaging it. In addition, it reduces analysis time, minimises chemical use and laboratory waste, and provides greater detection sensitivity.
The samples in which DMFu is detected are analysed using an acetone extraction method and the substance is determined quantitatively in a gas chromatography system equipped with a mass detector.
In recent years, cases of skin allergies caused by contact with products manufactured in Asia and treated with DMFu have been detected in Europe. Manufacturers use DMFu as a fungicide to prevent micro-organisms from damaging leather goods during storage and shipping in humid climates. It has been found in silica gel bags that are inserted in leather products such as sofas and footwear, and it is sprayed in containers that transport the products. Contact with DMFu, even in very small concentrations, can cause skin irritations and eye damage.
In 2009, the European Commission adopted Directive 2009/251, which prohibits the use of DMFu in consumer products. In the absence of an official method of analysis, laboratories in the leather and footwear industries have developed their own techniques to achieve a rapid and efficient analysis. The authorities responsible for consumer safety, including the Catalan Consumer Agency, periodically analyse leather products in the EEI laboratory to ensure products contain no trace of DMFu. The leather manufactured by several tanneries is also monitored in the laboratory.