Henkel has developed a new range of laminating adhesives free of epoxy silanes and a new test method that requires a combination of several sophisticated analytical techniques to detect epoxy silanes and its degradation products in food contact application following FEICA’s recommendation.
 

Adhesive Suitable for High-temperature Food Contact Applications

The adhesive system, are specifically designed for high-temperature food contact and medical retort applications, are modular in their design: The adhesive base Loctite Liofol LA 2798 can be combined with a variety of hardeners, making it versatile and reducing complexity for converters. Henkel offers four hardeners, each with different features to cover a broad range of applications.

For dried animal food or hot filling goods, Henkel provides two aromatic hardeners for boiling and pasteurization. These medium-high performance systems can be cured at room temperature and are designed for high temperature resistance and high heat-sealing strength. For high performance, Henkel offers an aliphatic hardener for general retort, which cures at room temperature and is recommended for 45-minute sterilization processes at 134°C. This makes it the ideal high-performance adhesive for baby foods, for example.

For the packaging and sterilizing of liquid, aggressive filling goods such as fatty foods and oily fatty contents such as cat food, Henkel recommends another hardener combination. This system is designed for processing temperatures of 134°C for 45 minutes, and its modularity enables customers to reduce complexity while providing flexibility.
 

EU Regulation on Use of Epoxy Silanes According to Genotoxic Potential

GLYMO is used in a wide variety of food contact applications, the European Food Safety Authority (EFSA) had a closer look at existing toxicological data. In 2017, EFSA concluded that GLYMO must be considered to have a genotoxic potential.

“Therefore, the European Union is now working on a legislative framework for 2020 to regulate the use of epoxy silanes according to their genotoxic potential. The deadline is envisaged for September 2020. This will raise demand for suitable alternatives,” said Dr. Monika Toenniessen, head of Food Safety Compliance – Global Food Safety, Product Safety and Regulatory Affairs. FEICA, the Association of the European Adhesive & Sealant Industry, already recommends replacing the adhesion promoter as soon as possible.
 

Using GLYMO-free Packing for Fatty and Aqueous Filling Goods

The application of GLYMO as an adhesion promoter will still be permitted if it can be demonstrated that it does not endanger human health. Products containing epoxy silane are not permitted to be used for fatty filling goods, and epoxy silanes must not be detectable in aqueous filling goods.

“The critical part, however, will be that converters and packaging manufacturers need to provide proof for the absence of GLYMO and structurally similar chemicals such as GLYEO. This implies two factors: having the right adhesive and the right testing method to prove it. Henkel Corporate Analytics developed a unique approach for determination of GLYMO & GLYEO derivates, which is leading within the market. The testing, however, will create additional workload and administrational paperwork for the converter’s quality control departments,” explains Dr. André Weiss, manager instrumental analytics, project management food safety.