DFA and TFA

What are DFA and TFA?

Difluoroacetic acid (DFA) and trifluoroacetic acid (TFA) are short-chain fluorinated organic acids that are particularly relevant as degradation products of other fluorinated compounds. TFA belongs to the group of ultra-short-chain PFAS and is characterised by its high stability and mobility in the environment. As a result, the substance can persist in water, soil and other environmental compartments for extended periods.

There are various pathways through which these substances can enter the environment. TFA can form through the degradation of certain fluorinated pesticides, refrigerants, propellants and other fluorinated industrial chemicals. PFAS from industrial applications and consumer products can also contribute to environmental contamination. DFA, on the other hand, is particularly relevant as a metabolite of the pesticide active substance flupyradifurone.

Where are DFA and TFA Found?

Due to their high environmental stability, DFA and particularly TFA can occur in a wide range of sample matrices. TFA is widely distributed and therefore cannot be clearly associated with specific products or product categories.

DFA, on the other hand, is frequently detected as a degradation product of the pesticide flupyradifurone. DFA can therefore be particularly relevant in plant-based foods, especially grapes.

Why are DFA and TFA Relevant?

DFA and TFA are primarily of interest due to their occurrence as residues or contaminants and their relevance for analytical testing. However, the two substances differ in terms of their toxicological and regulatory classification.

TFA is suspected of having reproductive toxic properties. At the same time, the available toxicological data remains limited. Due to its high stability and widespread presence in the environment, TFA is receiving increasing attention.

DFA is particularly relevant as a degradation product of the pesticide active substance flupyradifurone. Maximum residue levels have been established for DFA in various types of fruit and vegetables, making analytical monitoring of these products important.

In addition, the topic has received considerable media attention in recent years. As a result, TFA in particular, as well as the analytical assessment of fluorinated residues in general, is increasingly becoming a focus for businesses, consumers and other market participants.

Why Should Products Be Tested for DFA and TFA?

Testing for DFA and TFA enables companies to determine the concentrations of these substances in their products. Given the high level of public interest and media coverage surrounding the topic, analytical monitoring can provide valuable information about potential contamination.

TFA is receiving increasing attention from regulatory authorities, the food industry and the public due to its widespread occurrence, extreme persistence and new toxicological findings.

Maximum residue levels have been established for DFA in fruit and vegetables. For TFA, however, no maximum residue levels have currently been established. The concentrations determined can also be used to assess compliance with toxicological reference values such as the Acceptable Daily Intake (ADI).

The European Food Safety Authority (EFSA) has established an Acceptable Daily Intake for TFA of 0.014 mg/kg body weight per day and has derived an acute reference dose of 0.07 mg/kg body weight for the first time. According to EFSA’s assessment, the toxicological reference values of the parent substance flupyradifurone apply to DFA. The ADI is 0.064 mg/kg body weight per day.

DFA and TFA Analysis at GALAB

GALAB offers analytical testing for difluoroacetic acid and trifluoroacetic acid. The analysis is performed using a method based on the QuPPe method for polar pesticides.

The limit of quantification is 0.01 mg/kg. This enables GALAB to support companies in monitoring DFA and TFA concentrations in suitable sample matrices.