QAC Residues Update

News | 15 August 2012

An alert from QS Fachgesellschaft Obst-Gemuse-Kartoffein GmbH on the 20 April 2012 raised the issue of Didecyl Dimethyl Ammonium Chloride (DDAC) and Benzalkonium Chloride (BAC) residues on fresh fruit and vegetables. More recently based on toxicological endpoints derived by the German Risk Assessment Body BfR, a new MRL of 0.5ppm has been proposed.

Legislation
Didecyl Dimethyl Ammonium Chloride (DDAC) and Benzalkonium Chloride (BAC) are the most widely used QAC disinfectants in the UK and European disinfectant industry.  They are both supported for pt2 and pt4 applications (this covers food processing) of the European Biocidal Products Directive (98/8/EC). Shortly to be replaced with Regulation (EU) No 528/2012 of the European Parliament and of the Council of May 22nd 2012 concerning the making available on the market and use of biocidal products.

Non disinfectant applications are covered by REACH - Regulation (EC) No 1907/2006 and amendments.

Holchem do not believe that the use of Didecyl Dimethyl Ammonium Chloride (DDAC) and Benzalkonium Chloride (BAC) also known as Alkyl Dimethyl Benzyl Ammonium Chloride for the surface disinfection of food contact surfaces falls within the scope of the pesticide legislation currently in force with the European Union.
The scope of the regulation states in section 1.(a) that it applies to products for  “protecting plants or plant products against all harmful organisms or preventing the action of all organisms, unless the main purpose of these products is considered to be for reasons of hygiene rather than for the protection of plants or plant products;”   

Recently based on toxicological endpoints derived by the German Risk Assessment Body BfR, a new MRL of 0.5ppm has been proposed.  Based on this the Standing Committee of the Food Chain and Animal Health (SCoFCAH) has issued guidelines stating that Food and Feed of Animal Origin with a level of BAC high than 0.5ppm (mg/Kg) should not be placed on the market and be withdrawn from the market and disposed of safely.

Products, application and toxicity
QAC based disinfectants are not only the most commonly used actives they also are highly effective, safe and economic and form part of the whole cleaning and disinfection process. These actives are not banned for use in hygiene products.
Neither QAC is classified as Toxic. By calculation it is possible to demonstrate that it would be necessary to consume significant volumes of the in-use product to exceed the LD50 value for the QAC.

Summary
Holchems’ reading of the Pesticide Regulation leads us to believe it does not apply to utilising QAC actives for hygiene purposes; i.e. cleaning and disinfection of food contact surfaces.  Holchem do not recommend the use of QAC based products for cleaning or disinfection of food stuffs.  Holchem believe that when the QAC based products are used as directed by the Cleaning Instruction Card there is no evidence to suggest that food safety is compromised.

QAC’s are readily water soluble, if a business has concerns about the potential for transfer of the QAC’s to Produce we recommend rinsing of the food contact surfaces with potable quality water to remove the disinfectant; after a suitable contact time (15 minutes).

Other technologies are available for surface disinfection but we do not believe that a substitution is necessary.

Food producers have a duty to ensure that food placed on the market is safe.  Holchem recommend that businesses satisfy themselves that produce is supplied from growers or upstream producers within the relevant MRL limits.  Equally food producers should consider satisfying themselves that produce is not being contaminated by poor disinfection techniques.