Quaternary Ammonium Compounds
Quaternary ammonium compounds (also known as QACs or quats) are a class of industrial chemicals that are of economic importance. They belong to the group of cationic surfactants, which are substances with active effects on surfaces. They display both a hydrophobic (water-repelling) alkyl chain and a hydrophilic (water-soluble) group in their molecule, making them soluble in water as well as in fat. Due to this property, they are capable of binding dirt and fat in water. Some QACs, such as benzalkonium chloride (BAC) or didecyldimethylammonium chloride (DDAC), can accumulate in the fatty cell membranes of organisms and thus damage or functionally impair those cell membranes. Because of this, they have antiseptic effects and one application for them is as a biocide in disinfectants. However, there are numerous applications in both the public and industrial sector. QACs are used in hospitals, agriculture, industry, and food processing. They can also serve as a preventative measure against bacterial infection or pest infestation and can be used as plant protection products, plant fortifiers, or as fertilizers.
After being applied, QACs adhere strongly to the treated surface and are difficult to wash off with water alone. However, they can easily be absorbed by foods with high fat and protein content, such as dairy products, meat, or fish. If devices or surfaces that come into contact with food are disinfected and then not sufficiently cleaned with hot water, QAC residue can be transferred to the food. Due to the widespread use of QACs, it is generally possible for contamination to occur in any kind of food.
When considering the potential risks of using QACs, one has to take into account how it is treated legally. DDAC and BAC are no longer permitted in the European Union as active substances for plant protection products. In 2014, Regulation (EU) No 1119/2014 set a temporary maximum residue level (MRL) of 0.1 mg/kg for both substances in all food products, amending Annex III of Regulation (EC) No 396/2005. It legally makes no difference whether the residue arises from its use as a biocide or as a plant protection product. The new maximum residue levels were originally supposed to be valid for a period of five years, i.e. until the end of 2019, and subsequently reviewed. However, at the Standing Committee’s meeting in June 2020, the EU Commission decided not to carry out the review this year due to the COVID-19 pandemic. They also would like to take into consideration the effects of the increased use of QACs during the current situation with the novel coronavirus. Therefore, the complete monitoring data from 2014 until the end of 2020 should be collected before beginning the evaluation.
The GBA Group carries out tests for quaternary ammonium compounds in a variety of food products by means of LC-MS/MS technology. If you have any questions about the analysis or the legal situation, we will gladly assist you.