EHEDG and 3-A Hygienic Design on a Packaging Machine: What to Specify, What to Verify, and What the Evidence Does Not Settle

Product-contact material and finish: what to write into the specification

Start with the surfaces the product actually touches. Two independent publishers report the same Ra ≤ 0.8 µm figure for product-contact surfaces, which makes it a consistent screening value you can put in a specification rather than a number you have to negotiate^3,8(supplier-reported figure).

Neither publisher quotes it from EHEDG or 3-A standard text, so treat it as a reported industry screening value, not a mandatory limit^3,8. On grade, the sources converge on 304 as the baseline and 316L as the higher-corrosion-resistance option where the product or the cleaning chemicals demand it^3,18,25.

One supplier series illustrates the pattern: SUS304 throughout with Ra ≤ 0.8 µm on product-contact surfaces, and a SUS316L upgrade for all product-contact components in high-chloride applications such as seafood⁸(supplier-reported). That is the supplier's own configuration, not a rule about which grade your product needs — the sources give no product-specific selection rule^3,8,18,25.

When you review quotes, rule out any that leave the grade or the finish open. A quote that says "stainless steel" without naming 304 or 316L, or that omits a surface-finish figure for product-contact areas, gives you nothing to inspect against on delivery^3,18,25.

Ask the supplier to state the grade per component and the Ra value for product-contact surfaces in writing before you compare prices.

Welds and frame construction: ruling out harbourage points

Welds and frame joints are where a hygienic machine is usually lost. Independent supplier and peer sources describe the same expectation for product-contact and splash zones: continuous welds, ground smooth and electrochemically passivated, with no deep grooves and no exposed threads near the sealing zone^8,15.

Sealed and continuous welds appear again in a thermoform machine specification, alongside inclined surfaces that let water drain during cleaning¹⁶. Frame construction matters for the same reason.

Open-channel or solid-barstock frames are described as eliminating harbourage points compared with hollow-body alternatives, because a hollow section gives residue and moisture somewhere to sit that you cannot reach with a hose or a swab²⁰.

One supplier series combines this with 3 mm minimum internal corner radii and tool-less disassembly of product-contact parts, which is what makes a deep clean possible without a maintenance window⁸. Another specifies sealed and continuous welds with easy-open side guards and inclined drainage surfaces¹⁶.

These are supplier design descriptions, not verified certification, and the evidence gives no numeric weld acceptance criterion or inspection method^8,16,20. So the practical move is to make the construction inspectable: ask for the weld treatment (ground and passivated, or not), the internal corner radius, and whether product-contact parts come off without tools.

A quote that cannot answer those three is a quote you cannot clean.

Drainage and cleaning access: rejecting pooling surfaces and dead zones

A polished surface can still hide poor drainage, which is why the drainage and access check comes before the finish check in a peer buying guide¹⁵.

The sources require sloped, self-draining surfaces, but they do not agree on the number: one peer source gives ≥3° as the general self-draining slope, while a supplier series specifies 5° on all horizontal panels^3,8.

That difference reads as a minimum-versus-design-choice gap rather than a contradiction, and no standard text in the evidence fixes either value^3,8. Access is the other half.

A supplier series specifies 400 mm leg clearance for under-machine cleaning and tool-less disassembly of product-contact parts⁸. A peer source puts it more bluntly: the machine should empty fully without standing water after washing, and small dead legs may become serious hygiene risks¹⁵.

Where the product is liquid, gel, sauce or cream, or where you change over frequently, CIP is described as the recommended cleaning control because it cleans product-contact paths without major dismantling and reduces the contamination risk that manual cleaning carries²³.

For your specification, the check is concrete: ask the supplier to state the slope on horizontal surfaces, the clearance under the frame, and which product-contact parts can be reached without dismantling.

Then ask for the CIP design detail — spray coverage, pressure, drainage and access — because effective cleaning depends on those four, not on the surface finish alone¹⁵.

Documentation and certificate evidence to demand before the purchase order

A 3-A symbol claim is checkable: 3-A operates a certification scheme with conformance evaluators and a searchable certificate database, so you can look up whether a certificate is current rather than accept a logo on a brochure^4,13.

No equivalent verification route for an EHEDG claim is described in this evidence, so an EHEDG-aligned statement should be treated as a design description until the supplier shows you something more⁸. Request the following before releasing the order:

• ✓Material certificates for product-contact components, naming the stainless grade
• ✓Cleaning records and inspection reports from the supplier's own build or test runs
• ✓A written cleaning validation procedure, not a brochure statement
• ✓The 3-A certificate number, checked against the 3-A certificate database
• ✓Written confirmation of lead time, spare parts and after-sales response
• ✓Documentation to support your own validation and audits, where the supplier offers it

Cleaning validation: what to require, and what to agree with the supplier

Cleaning validation is treated across the sources as a documented, verifiable activity rather than a claim. A peer buying guide tells you to request a cleaning validation procedure, not a simple brochure statement, and to check whether pipes, valves and sealing tools can be inspected easily¹⁵.

Another source sets out the content: develop and validate cleaning SOPs including detergents, contact times and rinse requirements, then verify with microbiological swab tests or ATP hygiene checks after commissioning and periodically thereafter¹⁸.

EHEDG publishes a guideline titled Cleaning Validation, Monitoring and Verification, which confirms the topic exists as a formal subject, but the evidence here is a catalogue listing only — the guideline content is not available, so it cannot tell you what the procedure must contain⁵.

Where product-contact surfaces are not easily accessible because of the equipment design, swab sampling may be impractical and alternative sampling methods are needed; that guidance comes from pharmaceutical API cleaning validation, not from food packaging machinery, so use it as a prompt rather than a requirement⁷.

The gap you have to close yourself is the target. No source in this set states a log-reduction target or a cleaning time in minutes per cycle for a packaging machine^5,7,10,15,18.

So write the validation requirement as an agreement: ask the supplier to propose the detergent, contact time, rinse and verification method for your product, and to state what result counts as clean. That is a question the supplier can answer; a standard cannot.

Modelling the cost of the hygienic option over the machine's life

Hygienic capability carries a reported cost premium, and it is worth knowing the shape of it before you decide. One peer source puts IP65 washdown at +10–20% over an IP54 baseline and IP69K steam-clean capability at +30–50%³(supplier-reported).

Higher automation carries its own premium: automated, high-speed or multi-functional machines are reported at 20–35% more than standard systems⁶. Those are reported market estimates, not quotes, so use them to frame the decision rather than to budget a line item^3,6.

Model the total cost across a 5–7 year horizon, covering initial investment, operating cost including cleaning, materials, maintenance and long-term value^11,29. That framing matters because rated throughput is measured under ideal conditions, and changeover and cleaning downtime between SKUs reduce real output below the datasheet figure¹¹.

A machine that cleans faster or needs less dismantling shows up in that gap, not in the purchase price. What you cannot do from this evidence is close the cleaning-cost side numerically.

No source quantifies cleaning chemical, water, labour or downtime cost for a hygienic versus a non-hygienic packaging machine^3,11,29. So build the TCO model with your own plant's cleaning hours and chemical consumption as inputs, and treat the hygienic premium as a known cost against an unquantified saving.

The two figures the sources disagree on

What the sources do not establish

• No EHEDG or 3-A standard text in this evidence states the actual requirements for surface finish, weld quality, slope, frame construction or product-contact materials — only catalogue listings and peer/supplier paraphrases are available.
• No source identifies which specific 3-A standard or EHEDG guideline applies to packaging machines, or what a certificate number or documentation package must contain.
• No source gives a validated log-reduction target or a cleaning time in minutes per cycle for a packaging machine configuration.
• No source quantifies cleaning chemical, water, labour or downtime cost for hygienic versus non-hygienic packaging machines, so the TCO case for hygienic design cannot be numerically closed.
• No source gives lead times or spare-part availability data for hygienic packaging machines.
• No source addresses whether EHEDG certification of a machine is required versus self-declared alignment, or how a buyer verifies an EHEDG claim — no equivalent of the 3-A certificate database is described.
• No source covers validation of the machine's own cleaning procedure against a defined target microorganism for food packaging applications.