HOCl for Food Processing

Sanitation in a food plant fails for ordinary reasons. The concentrate ran out on the night shift. The dilution was eyeballed. A drum was stored in the wrong place. A drain was cleaned last and the mop went back through zone 2 on the way. None of these are chemistry problems, and none of them are solved by buying a stronger chemical.

Onsite hypochlorous acid generation attacks a different part of the problem: it removes the concentrate, the dilution step and the supply risk, and replaces them with a solution made at a set strength, a few metres from where it is used, from salt, water and electricity. This page sets out how that works in a food manufacturing plant — where the solution is used, what the rules say, how systems are sized, how the programme is verified, and what it costs.

The sanitation problem in a food plant

Three things make plant sanitation hard, and they compound.

Harbourage. Environmental pathogens do not live on the surfaces you can see. They live in hollow rollers, cracked welds, worn gaskets, standing water under equipment feet, drain junctions, insulation and wet ceilings — the places a schedule rarely reaches and a swab plan sometimes misses.

Biofilm. Once an organism is established in a niche, it protects itself in a matrix that shields the cells inside it. Biofilm is a physical problem as much as a microbiological one, which is why mechanical cleaning is not optional and why chemistry alone rarely resolves a persistent site.

Variability. Sanitation is executed by people, at speed, at the end of a shift. Every step that depends on judgement — how much concentrate, how long to leave it, whether to rinse — is a place where the programme differs from the SOP. Auditors find the gap between the two more often than they find a wrong chemistry.

Onsite generation does not fix harbourage or biofilm; cleaning does. What it fixes is the third problem, and it makes the first two cheaper to attack, because solution at the point of use stops being a cost that has to be rationed.

What changes when the solution is made on site

The chemistry itself is not exotic. Hypochlorous acid is the active form of free chlorine, and a near-neutral solution keeps most of its chlorine in that form; our how HOCl works page covers the detail, and single-cell vs membrane explains why EcoloxTech systems produce one near-neutral stream at pH 5.0–6.5 rather than a low-pH anolyte and an alkaline by-product.

The organisms that drive risk here

The research hub indexes published work on hypochlorous acid and electrolysed water against these organisms under laboratory and plant conditions, including electrolyzed oxidizing water against E. coli O157:H7, Salmonella Enteritidis and Listeria monocytogenes, neutral electrolyzed water on stainless steel against E. coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes, inactivation of Listeria monocytogenes biofilms by electrolyzed oxidizing water and neutral electrolyzed water for sanitising cutting boards. These are studies, not claims for our systems; the pathogens page goes through each organism in detail.

Where it is used, zone by zone

Most plants organise sanitation into zones, from surfaces that touch product to the remote environment. The zone decides the frequency, the product and the verification.

The applications page lists every task with its method and the questions to answer before it goes into an SOP.

The regulatory position, in short

• Food-contact surfaces. 21 CFR 178.1010 permits hypochlorite sanitising solutions at up to 200 ppm available chlorine, used followed by adequate draining — draining, not rinsing. Electrolytically generated hypochlorous acid is not named separately; it qualifies as available chlorine.
• Process water and ice. FDA Food Contact Notification FCN 1811, held by EcoloxTech, covers hypochlorous acid in process water or ice contacting meat, poultry, seafood, fruits and vegetables and shell eggs, at free available chlorine not exceeding 60 ppm, with a drain step or potable rinse for product consumed raw. An FCN is effective for the manufacturer named in it and those who buy from them.
• Produce washing. 21 CFR 173.315 is a different provision with the opposite requirement — a potable water rinse. The two are routinely conflated.
• Your plan. FSMA preventive controls (21 CFR 117) require sanitation procedures, monitoring, corrective actions and verification; USDA FSIS plants work to sanitation SOPs under 9 CFR 416. GFSI schemes add chemical control, training and validation expectations.
• Claims. Generators are devices and carry no efficacy claims. Where a task requires a registered disinfectant with named organisms, use HOCl-AS200 per its label.

The full citations are on the regulations page; the practical version, including what you may and may not say to a customer, is on staying compliant with HOCl. The compliance and audits page maps it to scheme clauses and records.

Sizing a system for a plant

Sizing is driven by peak demand and storage, not by floor area. Four numbers decide it:

1. Litres per sanitation event for each task — measure it rather than estimating; a hose station uses far more than a spray bottle.
2. Events per day, including changeovers and the end-of-shift clean.
3. Peak hour: what the plant needs in its busiest hour, which is usually the post-production clean.
4. Storage: a holding tank lets a smaller generator serve a larger peak, because it produces through the quiet hours.

The buyer’s guide covers the sizing maths in general terms, and the free sanitation audit does it from your task list and invoices.

How implementation actually goes

1. Survey. Water hardness and quality, power, drainage, the install location, and the route to each point of use.
2. Task inventory. Every sanitation task, its current product, concentration, method and contact time. This is the document that decides everything else.
3. Classification. Which tasks move to generated solution, which stay on a registered product, and which need a detergent step that does not change at all.
4. Install and commission. Softener, filter, generator, tank, pumps and outlets; first readings logged as the baseline.
5. Pilot in one area. Baseline ATP and environmental swabs before, the same after, with the SOP written and followed.
6. Roll out area by area, keeping the incumbent product available until each area is signed off.
7. Update the plan. SOPs, chemical list, training records, and the sanitation controls in the food safety plan.
8. Review at 30 and 90 days. Strength logs, verification trends, salt and power use, and the tasks that did not transfer.

The implementation page has the written procedures, schedules and the first-90-days plan.

Verification and records

A programme that cannot be evidenced is a programme an auditor will treat as absent. Three layers do the work:

• Process — free available chlorine and pH at the point of use, logged by shift, with a target range and an action when it is out of range.
• Visual — cleaned, fully wetted, left for the contact time, air dried or drained as the procedure requires.
• Outcome — ATP for residual organic matter, and environmental or product-contact swabs to your monitoring plan, trended rather than read one at a time.

Our free HOCl Compliance Pack includes the log, SOP and corrective action templates, ready to print.

The economics

The comparison is between an operating cost that never ends and a fixed cost with small running costs. Count what you spend today on the chemistry a generator would replace, plus freight, storage, dispensers, dilution labour, PPE and disposal; then count salt or brine, water, electricity, filters, service and test consumables. The difference is the annual saving, and the system, installation and distribution are the one-off.

Plants usually find the second-order items matter as much as the chemical line: floor space released, fewer deliveries, less handling, no run-outs, and fewer corrective actions caused by dilution error. The method, a worked example and a sensitivity table are on ROI and savings, and the plant-specific version is on the sector ROI page.

Five mistakes worth avoiding

1. Sanitising dirty surfaces. Soil consumes available chlorine. Clean first, every time.
2. Trusting a ppm reading alone. Without pH, a free-chlorine number does not tell you what form the chlorine is in.
3. Storing solution badly. Open, warm, sunlit storage loses strength quickly. Closed, opaque, cool — and test before use.
4. Ignoring feed water. Hardness scales the cell and shifts the output. Softening and filtration are part of the install, not an optional extra.
5. Assuming it replaces everything. Detergents stay. Registered products stay where the claim has to be on a label.

A day on the floor

What changes day to day is smaller than the business case suggests, and that is the point. A typical wet-clean shift looks like this once a system is in:

1. Pre-op. The sanitation lead draws solution at the station, checks free available chlorine and pH, and logs both against the target range for the area.
2. Dry pick-up and dismantle. Unchanged. Product debris is removed mechanically before anything wet appears.
3. Detergent and mechanical clean. Unchanged. Foam, scrub, rinse — the step that actually removes soil and disrupts biofilm.
4. Sanitise. Solution is applied at the set point for the zone, kept wet for the contact time in the SOP, then drained or air dried as the procedure requires.
5. Verification. Visual inspection, ATP on the agreed points, and swabs to the monitoring plan.
6. Records. Strength log, verification results and any corrective action, signed at the end of the shift.

The visible differences are that nobody decants concentrate, nobody runs out, and the number on the log is a measurement of what was actually used rather than what was supposed to be mixed.

Water, salt and power

An onsite generator is a small process, and like any process it has inputs that decide how well it behaves.

• Feed water. Hardness is the main enemy: calcium and magnesium scale the cathode, cut efficiency and shift the output. Softening and sediment filtration ahead of the cell are standard on commercial installations. Iron, manganese and dissolved organics also consume available chlorine before it reaches a surface.
• Salt or brine. Food-grade, non-iodised salt without anti-caking agents, or ready-mixed brine. The additives in table salt foul cells. Brine containing acid is an input that needs its own handling — see HOCl safety and SDS.
• Power and space. A wall or bench location with drainage, ventilation and the manufacturer’s clearances. Cells vent small amounts of hydrogen in normal operation, so the area is ventilated and kept clear of ignition sources.
• Distribution. Tanks, pumps and drops turn a machine in a plant room into solution at the point of work. Getting this right is what stops people carrying buckets.

Materials and equipment

Near-neutral hypochlorous acid at use strength is gentler on stainless steel and aluminium than high-strength chlorine or low-pH anolyte, but any oxidiser can affect some materials over time. Before roll-out, check compatibility for the surfaces and equipment the solution will touch — including gaskets, seals, painted surfaces, soft metals and electronics enclosures — and set out in the SOP where a wipe or rinse follows. The HOCl-AS200 label notes that prolonged contact with metal may cause pitting or discoloration; treat that as the general rule for any chlorine-based chemistry.

Chemical control and your existing supplier

Onsite generation changes the approved chemicals list, so it has to go through the same control as any other change: update the list, hold the SDSs for the solution and for every input, label secondary containers, segregate incompatibles, and control who can change a set point. Most plants keep their detergent supplier and their registered disinfectant; what changes is the volume chemistry in between. Telling your supplier early usually produces a better conversation than discovering the change at the next audit.

What it does not do

• It does not clean. Hypochlorous acid has no meaningful detergency. Soil comes off mechanically and with a detergent, first.
• It does not carry label claims. The generator is a device. Registered claims belong to registered products.
• It does not survive bad storage. Strength falls in open, warm or sunlit storage; produce close to use and test what you store.
• It does not fix a schedule. Better chemistry applied to the wrong surfaces on the wrong frequency produces the same result the old chemistry did.

The rest of this programme

This pillar is the overview. Six companion pages go deeper:

• Pathogens — the organisms that drive risk, and where each one hides.
• Applications — every task, zone by zone, with method and set point.
• vs. Chemicals — an honest comparison with quats, chlorine, PAA and the rest.
• Compliance & audits — FSMA, FSIS, GFSI and the records that satisfy them.
• ROI & savings — the model, run on plant numbers.
• Implementation & SOP — survey to first audit, with written procedures.

Frequently asked questions

The seven-part programme