Electrochemical Activation of Water (ECA-Water): The Fundamentals

Updates 27 June 2023

This is part of the series: “ECA Generated Radical Water.” All articles in the series are listed there.

Fundamentals of the System

I list the fundamentals of the two products generated through the ECA process at a total cost of 3g of salt per L product. The products have a wide range of applications in a meat factory. The total cost of ownership will include the ECA generator and two cells to be replaced every few years. This will vary depending on the model of the ECA generator installed. Even with this cost added in, the total cost of ownership is far less than using commercial cleaning chemicals).

Two products are produced namely anolyte and catholyte. They have the following characteristics.

Catholyte

Effective as a mild degreaser in CIP and as a component to a strong degreaser if combined with specially formulated soap;
In meat formulations, it is an acidity regulator, replacing phosphate to facilitate water binding and act as an effective salt replacer.

It has the following characteristics:

Alkaline
NaOH -> Sodium Hydroxide known as lye or caustic soda.
Mild degreaser;
Excellent anti-oxidant;
Detergent.
pH > 9
Negative oxidation redox potential (ОRP)

Anolyte

Extremely effective sanitiser in CIP;
Highly effective in decontamination of meat and meat products, pre-and post-processing.

It has the following characteristics:

Anolyte – pH neutral (pH 6 – 7);
Disinfectant;
Strong oxidising agent;
Excellent against biofilm;
High ORP (Positive oxidation redox potential (ОRP))
Shelf life extender
Can be corrosive
pH neutral HOCl -> Hypochlorous acid;
- Weak acid
- ClOH, HClO, HOCl, or ClHO
pH is 7,5 – 8 -> an anion OCl^– (Hypochlorite)

The extremely high efficacy of anolyte in disinfecting is ascribed to the following. “At an acidic to neutral pH, the predominant chemical species is hypochlorous acid (HOCl) with a high oxidation-reduction potential (ORP) of 244 ≥1,000 mV (Guentzel et al., 2008). The effectiveness of hypochlorous acid as an active sanitizing agent is determined in large part by the pH. Hypochlorous acid exists interchangeably with other chlorine species, including chlorine, hydrogen chloride (aqueous and gaseous) and hypochlorite. The pH is believed to reduce bacterial growth and make the bacterial cells more sensitive to active chlorine. Active chlorine compounds can destroy the membranes of microorganisms, but other modes of chlorine action (e.g., decarboxylation of amino acids, reactions with nucleic acids, and unbalanced metabolism after the destruction of key enzymes) have been reported as well (Huang et al., 2008; Hricova et al., 2008; Guentzel et al., 2008; Young and Setlow, 2003).” (Guentzel et al., 2008)

“In Huang’s et al., 2008 review of the scientific literature, the authors suggested that hypochlorous acid penetrates cell membranes and produces hydroxyl radicals, which exert their antimicrobial activity through the oxidation of key metabolic systems. Hricova et al., 2008 reported that researchers suggested that the high ORP is the determining factor for the antimicrobial activity of acidic anolyte. The ORP of a solution is an indicator of its ability to oxidize or reduce, with higher ORP values corresponding to greater oxidizing strength. The high ORP and low pH of acidic anolyte seem to act synergistically with hypochlorous acid to inactivate microorganisms (Guentzel et al., 2008).” (Hypochlorous Acid TR 08 13 15)

Application Chart of Anolyte and Catholyte in a Meat Factory Environment

The following chart shows the different application dilution levels currently in use in the Isolo factory in Lagos.

Product	Application	Dilution %	PPM	Comments
Catholyte 800ppm in neat product NaOH	Lobby – boot wash	12%	96	Mix into the soap dispensers for the automated boot wash systems with regular soap for boot washing.
	Emulsion products	25%	200	Mix into emulsion products by making a tray with catholyte and by using the water mixed with catholyte as the water in the emulsion. Water inclusion rate on average 30% of total emulsion.
	Whole meat	25%	200	Use catholyte water in brine make-up. Injection rate between 30 and 65%.
	CIP – with foaming soap in foaming pots	12%	96	Mix catholyte with foaming soaps in pots for CIP equipment and plant.
	Wash Bay – mix with soap	12%	96	Use catholyte water in brine makeup. Injection rate between 30 and 65%.
	Water pales for blockman	100%	Sanitiser spray after CIP.	Use catholyte water in Diesel Electric high-pressure sprayers with heating elements.

Anolyte 500ppm HOCl in neat product	General water supply	1%	5	100% catholyte in pales with every blockman to rinse fat off hands during deboning. Spare knife in a tray next to pale with anolyte to sterilise knife. After every quarter deboned, the water in the bucket must be replaced with fresh water.
	Carcass wash	40%	200	Wash carcasses before it enters the facility.
	Spray sausages with solution post-pealing, before packaging.	10%	50ppm	Sanitiser spray after CIP. Use as a disinfectant to rinse off soap after soap cleaning. Leave a few minutes and rinse off with regular water (with 1% anolyte). Leave for the night to dry.
	Spare knife for deboners	100%	500ppm	CIP – rises off after soaping

Anolyte and Catholyte: Considerations Around Stainless Steel

-> Catholyte or NaOH (sodium hydroxide; ECA generated Catholyte) in soap:

– As a general rule, it is recommended to avoid using highly alkaline solutions on stainless steel as they can cause damage.

– A safe ppm concentration of NaOH in the soap for contact with stainless steel would typically be very low, likely less than 100 ppm as a guideline, depending on the specific stainless steel grade and quality.

– The Catholyte generated with the ECA equipment currently used by us contains 800 ppm NaOH. This means that we will use a 12% solution with the soap we designed for use with the catholyte.

– We recommend the use of Catholyte as a detergent in combination with a soap, designed to enhance the degreasing capabilities. The same basic formulation and dilution ratio of NaOH of 12% or 96ppm is recommended for boot washing with the only difference being the removal of the foaming agent.

-> HOCl (hypochlorous acid) as a disinfectant:

A technical committee of the USDA cited throughout this document reported that “the problem of corrosion to processing equipment or hand irritation is a lesser concern when using neutral EW (anolyte). Stainless steel is very resistant to chlorine products. The solution is stable and chlorine loss is significantly reduced at pH 6–8 (Ayebah et al., 2005 and Len et al., 2002).” (Hypochlorous Acid TR 08 13 15)

Irrespective of the findings of the technical committee, limiting the concentration of stainless steel to 200ppm will eliminate any risk to stainless steel surfaces and also comply with the committee’s recommendations for its use as a pesticide.

Generally, we, therefore, state that:

– Hypochlorous acid, which is the active ingredient in bleach, may also be corrosive to stainless steel if used at high concentrations or for prolonged periods which is not the case with anolyte, but we still heed the caution.

– A safe ppm concentration of HOCl in a sanitiser for contact with stainless steel would generally be low, typically less than 200 ppm which is also in line with the USDA’s recommendation of its concentration level as a pesticide (see USDA CAS No.: 7790-92-3).

Anolyte generated through the ECA process has, however, been proven to be extremely effective in a CIP application and Radical Waters recommends a concentration of 50ppm (40% dilution).

Regulatory Framework as CIP

– Anolyte (HOCl – Hydrochlorous Acid at Neutral pH)

A technical evaluation report by the USDA’s National Organic Standards Board (NOSB), dated August 13, 2015, concluded the following (Hypochlorous Acid TR 08 13 15):

“A number of studies have demonstrated the strong antibacterial activity of EW (anolyte) water against 100 foodborne pathogens on raw agricultural products and food contact surfaces. Applications of EW (anolyte) as a disinfectant for reducing microbial contamination have been reported for fresh fruits and vegetables, poultry carcasses, shell eggs, cutting boards, and food processing surfaces. Some advantages of using EW (anolyte) water are:

EW (anolyte) is as effective as any chlorine treatment,
it is not necessary to handle potentially dangerous chemicals, e.g. chlorine gas, chlorine dioxide, bleach,
the apparatus to produce EW (anolyte) is relatively inexpensive and easy to operate,
because only water and sodium chloride are used EW (anolyte) production is environmentally friendly and
the properties of the EW (anolyte) can be controlled at the preparation site (Su et al., 2007).”

Related to HOCl, the following regulations apply.

United States:
- The U.S. Food and Drug Administration (FDA) has approved the use of hypochlorous acid as a sanitiser in food processing, including for meat and poultry.
- The Code of Federal Regulations (21 CFR 173.315) allows the use of chlorine-based sanitisers, including hypochlorous acid, on meat and poultry surfaces as long as they are used in accordance with good manufacturing practices.
European Union:
- The European Food Safety Authority (EFSA) has established guidelines for the use of chlorine compounds, including hypochlorous acid, as sanitizing agents in food processing.
- The specific permissible levels expressed as parts per million (ppm) may vary depending on the application and local regulations within individual EU member states.

In addition, the technical report from the USDA references “the Food and Drug Administration (FDA) regulations (21 CFR Part 178) which permit the use of sanitizing solutions containing sodium hypochlorite on food processing equipment and food contact surfaces. The active ingredients in these solutions are the chlorine oxidants hypochlorous acid, hypochlorite ion and free chlorine:

The following provisions must be followed:
1. Equipment or articles sanitized with the solution must be allowed to drain adequately before contact with food.
2. Solutions used for sanitizing equipment shall not exceed 200 parts per million (ppm) of available chlorine.

To eliminate any chance for a corrosive effect on equipment, following the disinfecting of food contact surfaces, we will add a water rinsing step afterwards containing 5ppm anolyte (1% of a neat 500ppm anolyte product).

“The USDA’s Food Safety and Inspection Service Directive 7120.1 “Safe and Suitable Ingredients Used in the Production of Meat and Poultry Products”, has approved the use of electrolytically generated hypochlorous acid as a food additive for use on meat and poultry products. It is allowed for use on red meat carcasses down to a quarter of a carcass, whole or eviscerated poultry carcasses, in water used in meat and poultry processing, in poultry chiller water, for reprocessing contaminated poultry carcasses, on giblets and salvaged parts, and on beef primal cuts of beef. Depending on the product sanitized from 5 to 50 ppm free available chlorine can be used.” (Hypochlorous Acid TR 08 13 15)

– Catholyte (NaOH or Sodium Hydroxide)

As far as NaOH is concerned, it can be used indirectly in meat processing facilities for cleaning and sanitation purposes. It may be used as a part of cleaning agents or sanitisers that are applied to surfaces, equipment, or utensils in the processing area. The use of NaOH or NaOH-containing products for sanitation purposes is regulated and must comply with food safety guidelines and regulations.

We have, however, designed a soap with enhanced degreasing capabilities with a strong foaming agent to ensure sufficient contact time for enhanced effectiveness.

Carcass Wash with HOCl and General Disinfecting Efficacy

Related to the use of Anolyte created through the ECA process, “in their review of the scientific literature, Keskinen et al., 2009 reported that sanitizing washes are the most practical means of decontaminating raw produce. In commercial value-added produce operations, solutions that contained chlorine compounds (with concentrations varying from 50-200 ppm) and with contact times of 2 minutes or greater showed a decrease in the bacterial load 116 by from <1 log colony forming units (CFU)/gram (g) to 3.15 log CFU/g.” (Hypochlorous Acid TR 08 13 15)

“At a pH of 6.0-7.5 (neutral), EW (anolyte) (ORP=750 mV) contains primarily hypochlorous acid, hypochlorite ion and trace amounts of chlorine. The effectiveness of neutral EW (anolyte) as a sanitiser has been demonstrated for reducing Escherichia coli O157:H7, Salmonella enteritidis and Listeria monocytogenes biofilms on the surface of tomato (Deza et al., 2003) and also on plastic and wooden cutting boards (Deza et al., 2007).” (Hypochlorous Acid TR 08 13 15)

Anolyte “has been reported to have strong bactericidal effects on many pathogenic bacteria, such as Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella species (Kim et al., 2000). Suppression of fruit rot in pears caused by the fungus Botryosphaeria berengeriana was observed after dipping fruit in an EW (anolyte) water solution for as little as 10 minutes (Al-Haq et al., 2002).” (Hypochlorous Acid TR 08 13 15)

Application of Catholyte (NaOH) in Meat Formulations

We are primarily concerned with the use of NaOH in meat formulations and the following information applies as per Codex.

GSFA Table 3 Provisions

Sodium hydroxide is a food additive that is included in Table 3, and as such may be used in the following foods under the conditions of good manufacturing practices (GMP) as outlined in the Preamble of the Codex GSFA. Although not listed below, Sodium hydroxide could also be used in heat-treated butter milk of food category 01.1.1 and spices of food category 12.2.1. Note that food categories listed in the Annex to Table 3 were excluded accordingly. Sodium hydroxide is acceptable in foods conforming to the following commodity standards: CS 87-1981, CS 105-1981, CS 141-1983.

Sodium hydroxide is a: Acidity regulator

Any Acidity regulator listed in Table 3 can be acceptable for use in all products conforming to CS 117-1981, CS 309R-2011, CS 291-2010, CS 319-2015, CS 256-2007.