Win for Chemical Industry as Regulators Forced to Raise Safety Threshold for DDAC

In a strange twist, the use of an illegal plant strengthening product by an organic farmer has turned into a big win for industrial disinfectant users.

Illegal Organic Plant Product

It all started with an organic farmer in Germany. When the results of a laboratory test on his ruccola showed high levels of DDAC the farmer raised the red flag. Authorities got involved, and as the net of control samples widened, two things became clear:
  • The plant strengthening agent being used by the organic farmer contained DDAC as an undeclared, and illegal, ingredient.
  • Nearly all the fruit, vegetables, and milk on the market were contaminated with DDAC above the current legal limits.
DDAC -- a colorless, odorless quaternary ammonium compound used as a disinfectant and tenside -- was not approved as an ingredient for the plant-strengthening product, Vi-Care. Typically, DDAC residues occur on foods after contact with surfaces that have been disinfected using DDAC, which is a potent antimicrobial. The widespread applications for DDAC include cleaning equipment used to handle and process fruits, vegetables, meats, and other foodstuffs as well as milking machines.

Emergency Action by Food Safety Agency

DDAC has not been fully tested and proven safe yet, so under the European precautionary principle, the legal limit for contamination of food with the chemical was set at the extremely low level of 0.01mg/kg. In an emergency meeting of the Standing Committee of the Food Chain and Animal Health (SCoFCAH), the responsible body in the European Food Safety Agency (EFSA), the safety threshold was raised from 0.01mg/kg to a temporary limit of 0.5mg/kg -- high enough to allow 96% of the tested produce to remain legal under a new threshold 50 times the existing legal limits. They acted in the face of the threat of empty shelves due to the widespread findings of DDAC contamination.

The official press release of the SCoFCAH indicates levels of 1 to 4.3mg/kg in fresh herbs treated directly with the plant strengthener while recent reports in the German media (TAZ) cite levels as high as 0.92mg/kg, almost twice as high as the newly raised emergency threshold.

The report notes that the samples tested at these high contamination levels had NOT been treated with the DDAC directly. Although the exact source of contamination remains under investigation, the DDAC contamination most likely results from contact of the foodstuffs with disinfected equipment or from residues of DDAC in treated water used to wash the produce.

Scandal or No Concern?

The German CDU party called it a scandal, accusing the Red-Green coalition currently in control of the government of not taking seriously the fact the citizens have been unknowingly consuming contaminated foods. But consumer advocates, the German Institute for Risk Research (BfR), and the disinfection products industry associations advise consumers that there is no real risk to health.

On the face of the numbers, they are correct. the 0.01 limit is artificially low pending further study of the issue. It would be inappropriate to throw away all that food based on an overly conservative safety level, never mind the political implications of empty food shelves. The German BfR recommended that levels of up to 1mg/kg on bananas, citrus, and fresh herbs could be tolerated (the higher level probably due to the outer skins and low consumption quantities, respectively), while 0.1 mg/kg on all other foodstuffs should be safe. The EFSA committee gathered the best existing studies of DDAC, and plugged these into models intended to give a safety factor of 100 for the most vulnerable populations to determine the 0.5mg/kg limit.

However, question about the widespread use of DDAC remain. The chemical has very toxic effects on the aquatic environment, and in its concentrated form is considered harmful to humans and can cause burns of skin or mucous membranes. This burning effect makes setting a safe limit difficult, because the testing of animals with higher levels of chemical intended to mimic a lifetime of low exposure can produce symptoms related to the corrosivity of the chemical that would not be experienced when the chemical is "diluted" by eating food contaminated with it. Perhaps the most interesting question relates to the long term effect of consuming chemicals with anti-microbial effects on the health of the organisms that make up a healthy gut.

Industry associations (German) celebrated the decision, and the strange twist of fate that has opened the discussion and resulted in finding their product "safe." Meanwhile, the news has only just started to seep out into the mainstream media. We await the hue and cry as ordinary European citizens digest the news about what they have been digesting.

Win for Chemical Industry as Regulators Forced to Raise Safety Threshold for DDAC
Disinfectant suppliers declare the safety of DDAC as the threat of empty grocery shelves force revision of regulatory thesholds

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