Leuconostoc/Radish Root Ferment Filtrate, aka or Leucidal Liquid, has been a go-to preservative in recent years for companies looking for a safer, more natural alternative.
However, a recent study has found that the reportedly natural preservative is laced with a synthetic disinfectant called didecyldimethylammonium chloride. (Read the study in its entirety here.)
The researchers had been curious as to how the leuconostoc preservative actually worked to prevent bacterial growth, initially thinking that it contained natural peptides and acids. While they did find salicylic acid was a main constituent in radish root ferment filtrate, they found no peptides, and instead were suprised to find the synthetic didecyldimethylammonium chloride.
Once they were able to extract the two compounds from a sample of the radish root ferment filtrate, they did carbon dating on them and found at they were clearly from synthetic, petroleum-based sources, not from plants:
To determine the origin of the salicylic acid and didecyldimethylammonium salts we isolated from LRRFF, samples were submitted for carbon dating. On the basis of the amount of 14C present, these compounds were dated to 52 000 ± 2 900 and 21 140 ± 100 years old, respectively. This clearly indicates that the salicylic acid and the didecyldimethylammonium chloride are largely derived from petroleum-based precursors and that neither is the product of a recent fermentation of plant material.
They also tried making a radish ferment of their own, and found that no didecyldimethylammonium chloride is present naturally in radishes or their fermentation products.
Salicylic acid is known to be a weak estrogen mimicker, which I've written about here.
The study's researchers say that didecyldimethylammonium chloride has "toxicity to aquatic organisms and can also affect human health. They are known to enhance permeability of salicylic acid through animal skin, and can cause skin allergenic effects, asthma, and lung problems, as well as eye irritation."
The study was published in the Journal of Agricultural and Food Chemistry in March 2015; the manufacturer that holds the patent of the preservative does not appear to have made any public statements regarding this information. This is the first and only study on the topic.
Here is a list of products that currently use Leuconostoc/Radish Root Ferment Filtrate according to EWG.
There appear to be two different leuconostoc ingredients that are made by the same manufacturer: Arborcide OC and Leucidal Liquid.
Leucidal Liquid is the ingredient that was analyzed in the above study. On a product label it will be listed as Leuconostoc/radish root ferment filtrate.
Arborcide OC has not been independently studied. On a product label it will be listed as Leuconostoc ferment filtrate.
The EWG list does not differentiate between the two different products.