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HYGIENIC DESIGN · PROCUREMENT · R638 REGULATION 7
Key facts
- Four parts duty, geometry, materials and finish, evidence gates
- South African law R638 regulation 7, smooth, rust proof, non toxic, non absorbent, free of open joints or seams
- Internal radius 3 mm minimum at angles of 135 degrees or less, commonly cited from EHEDG Guideline 8
- Slope product contact surfaces drain to one side, 3 degrees minimum
- Clearance supplier guidance commonly asks for at least 200 mm under equipment, or a plinth sealed to the floor
- When to ask at the user requirement specification, when it costs the supplier nothing
Write the specification once, and stop paying for it nightly
Hygienic Design Essentials takes you from never having heard of EHEDG to writing radii, slopes and dead space limits into a purchase order, in five hours, with a thirty point line walk you run the week you finish.
What South African law already asks of your equipment
R638 of 2018, regulation 7, requires food contact surfaces to be smooth, rust proof, non toxic and non absorbent, and free of open joints or seams. Read that last phrase again, because it is a geometry requirement written into law. A lapped joint, a stitch weld and an open hollow section are all open joints or seams.
This matters commercially as well as legally. When a supplier tells you that a detail is optional, you are not asking for a preference. You are asking for something your regulator already requires, and that changes the conversation.
The four parts of a specification that works
1. The duty. What the machine handles, at what surface temperature including cleaning, the chloride it will see from product and water, the pH range from product and cleaning chemistry, and whether there is a kill step after it. Three of those four are numbers you can get this morning, and almost no specification states them.
2. The geometry. Internal radii, commonly cited at a 3 mm minimum on angles of 135 degrees or less, with 6 mm preferred and 10 mm in chutes where product is dropped. Product contact surfaces sloped to one side at a minimum of 3 degrees so they drain. No dead spaces, with the length to diameter limit stated and the document it comes from named. Continuous welds ground flush rather than stitch welds. No exposed threads. Seals flush with the product surface with the compression fixed by a shoulder.
3. Materials and finish. The grade, chosen from the duty rather than the catalogue, with the surface finish figure and the method that produces it. Elastomers specified against the temperature and the cleaning chemistry, not just named.
4. Installation. This is the part that gets forgotten and then ruins a good machine. Clearance to clean under and behind, and supplier guidance commonly asks for at least 200 mm under equipment fully and safely accessible, or a plinth sealed to the floor with no gap at all. It is the middle option, a gap of fifty or eighty millimetres, that fails. Services routed so they can be cleaned around. Cabinets off the floor with glands entering from underneath.
The evidence gates, and when each one closes
| Stage | What you ask for |
|---|---|
| User requirement specification | The duty, the geometry limits, the materials and finish, the installation requirements. Costs the supplier nothing at this point |
| Design review | Drawings showing sealed hollow sections, internal radii and continuous welds, with the numbers marked on them |
| Fabrication | A weld sample, the mill certificate, the surface finish figure and its method, the passivation record |
| Factory acceptance | Strip it down in front of them. Time how long it takes and who can reach what |
| Installation sign off | Clearances, access, services and drainage, before first product |
Every gate you skip returns as a cable tie about two years later, attached to a machine that is in production, out of warranty and impossible to take off the line for a week.
Where it sits in your management system
Hygienic design is not a standard of its own. It lives inside your prerequisite programmes, your maintenance and change control, and your equipment purchase process, which is exactly where auditors look for it. The useful discipline is to name the document behind every figure you specify, and to notice when a number in common use comes from guidance rather than from the standard being quoted at you. That habit alone changes how supplier conversations go.
What to do on Monday
Take your current equipment purchase form, and add four lines: the duty numbers, the geometry limits with their sources, the materials and finish with the method, and the list of evidence with the stage it is due at. One page. Then apply it to the next quote that arrives, and watch how much of it the supplier can already answer.
Frequently asked questions
What does R638 regulation 7 require of food equipment?
That food contact surfaces are smooth, rust proof, non toxic and non absorbent, and free of open joints or seams. It is a design requirement rather than a cleaning one, which is why cleaning cannot correct a machine that fails it.
What internal radius should I specify?
A 3 mm minimum on internal angles of 135 degrees or less is commonly cited from EHEDG Guideline 8, with 6 mm preferred and 10 mm in chutes and hoppers where product is dropped under force. Below 3 mm no brush, cloth or spray reaches the bottom of the angle.
How much clearance should there be under equipment?
Supplier guidance commonly asks for at least 200 mm under equipment, fully and safely accessible, or alternatively a plinth sealed to the floor with no gap at all. The failure mode is the middle option, a gap too tight for a cleaning tool and too open to seal.
Can I just ask suppliers for EHEDG certified equipment?
Certification helps but it does not replace a specification. It covers particular equipment types and particular tests, and it says nothing about how the machine is installed on your floor, which is where a good machine is most often ruined. Specify the duty, the geometry and the installation regardless.
We already own the equipment. Is this specification worth writing?
Yes, for two reasons. It is the document you use for the next purchase, and it is the yardstick for scoring what you already have. Walk the line against it, score the gaps, and you have a capital plan built on rules rather than opinions.
Write the specification once, and stop paying for it nightly
Hygienic Design Essentials takes you from never having heard of EHEDG to writing radii, slopes and dead space limits into a purchase order, in five hours, with a thirty point line walk you run the week you finish.