Wash-down vs Hygienic

You may have seen sensors where words lke "hygienic" or "washdown" occur.
But what does this really mean? 

So first, I want to explain why these types are neccessary in some business areas. 
 

The consumer and for sure their health are top priorities for the food and beverage industry. Contaminated food can be a high risk for diseases.  It is important, that companies do not damage their image and profit with recalls of food. So its clear that food and beverage manufacturerers want to prevent such scenarios. The primary goal is safe food. 

In food and beverage production, a distinction is made between the food area (in direct contact with the product), the spray area (product-related) and the non-food area. Depending on the area in which the components are used in the machine, there are different requirements for them. 

Food area

In areas in which the sensor may have direct contact with the unpacked food, the risk for contamination is increased. So it is important, that parts that may come into contact with the food must not have a negative effect on it. For example taste or food intolercances.

The following points must be considerd in areas like these:

• hygiene in production
• use of food contact materials
• equipment in hygienic design

These requirements give rise to the need for components that also comply with the hygienic design rules. If a supplier meets these rules, the machine manufacturer can use the components and the food or beverage producer can use the machines without hesitation.

Certifications:

There are different institutions which check the requirements and certify products. For example: 
EHEDG
3A 
FDA

What is hygienic design?

Many component suppliers offer different solutions with hygienic design. Each supplier interprets the design requirements a bit differently. So what does hygienic design really mean? 

• FoodContact Material (FCM) must be used as the material. This means the material must be non-corrosive, nonabsorbent and noncontaminating, disinfectable, pasteurizable and sterilizable. SICK is using V4A stainless steel as a suitable housing material.
• Additionally, seals must be used to prevent microorganism intrusion and the risk of partial loss must be minimized.
• Smooth surfaces with a radius of < 0.8 μm are accepted.
• There shall be no defects, folds, breaks, cracks, injection molded seams and connections even at material transitions.
• There must be no holes and depressions and no corners of 90 °.
• The minimum radius should be 3 mm.

What can products in hygiene design look like?

For example:

Typ:WL4S-3N1130H
Art-Nr.:1048116

or 

Typ:THTS-1AA520256MZ (GBC09)
Art-Nr.:6052958

Some properties which Sick offers in many hygienic products: 

Laser markings
Stainless steel housing (usually V4A)
High protection classes like IP69K
FDA certification

What is "Washdown"?

As soon as the sensor must operate in wet cleaning areas, the requirements change. So depending on the food to be processed, an additional distinction is made between dry and wet areas. For example: In a meat processing plant, for example, wet cleaning is used. As soon as wet cleaning takes place, we are in the washdown area. Washdown areas are areas that are designed for the special environmental conditions and the corresponding cleaning processes.

Washdown products must comply to the following requirements:

• Detergent/corrosion resistant materials (often these are even food compliant, but this is not a must).
• High IP class (usually IP67 and IP69K)
• Detergent resistant (ECOLAB and/or Diversey are known companies. Their cleaning detergents are used for special tests, also see: the Ecolab article for further information.)

 Summary
The overriding goal in the food and beverage industry is to ensure simple and safe cleaning of equipment. However, the different areas have different requirements for the installed components. In the food sector, hygiene design is in demand. Thus, the hygiene design components must meet food safety requirements. EHEDG, FDA and 3A are institutions that confirm and verify compliance with these rules and support companies in the development of these components. In the spray area, where wet cleaning is required, we need washdown components. The components here must be resistant to cleaning detergents and corrosion, and a higher degree of protection is required, often IP69K.