High Purity cleaning procedures
Since sanitising programmes have been commonly established, cleaning and sanitising procedures have to be developed for all food processing equipment. The objective of cleaning and sanitising food contact surfaces is to remove food (nutrients) which bacteria requires so that it can grow, and to kill bacteria that already exists.
Cleaning definitions
- Clean: Free from dirt, stain, or impurities and generally unsoiled
- Sanitised: Free from elements that endanger health, reduction of micro-organisms
- Desinfect: Refers to inanimate objects and the destruction of all vegetative cells (not spores)
- Sterilize: Refers to the statistical destruction and removal of all living organisms
ERIKS has wide ranging experience in material and product design compatibility to overcome problems in the cleaning processes used in the food, beverage and pharmaceutical industries.
Manual cleaning procedures
These procedures could be done by clean-up personnel, using:- buckets, brushes and hoses or
- HPLV-Systems (High Pressure Low Volume) via spray wands or
- by foaming (cleaning primarily by chemical action)
Mechanical cleaning procedures
System uses an agitated tank to clean components (equipment parts and short section of piping) disassembled and placed in the tank.
CIP (Clean-in-Place)
This cleaning process is usually accomplished via chemical action based on spray or pressure recirculation of the flush, wash, and rinse solutions under controlled conditions of time, temperature and chemical concentration. It involves the washing of processing and storage tanks, the piping systems and integrated equipment.
SIP (Sterilization-in-place)
The objective is to sterilize all sterile product contact equipment at its point of use to eliminate or reduce the need for aseptic additions or connections.
| Chemical | Example | Concentration | Temperature °C | Time | Cleaning procedure |
|---|---|---|---|---|---|
| Chlorinated alkalies | Mild solution of caustic soda | max. 0,5% | 55-70 | 5-22 | CIP |
| Acidified rinse | Post rinse, fresh water, acid solution | pH 5,5-6,0 | RT | - | CIP |
| Strong alkalies | Caustic soda | 0,5-5% | up to 90 | 45-90 | CIP |
| Strong acids | Phosphoric acid, nitric acid | pH-2 | 75-90 | 20-30 | CIP |
| Sanitiser | Sodium hypochlorite | 200 ppm active chlorine | cold | a couple of | CIP |
| Hot water | - | - | 80-90 | - | CIP |
| Steam | - | - | +130 | - | SIP |
Requirements to seals
The requirements to the seals and plastic parts are:
- chemical resistance against the product
- chemical resistance against the used CIP media
- good cleanable and sterilizable sealing surface
- good resistance against abrasion and wear
- nontoxic sealing material
- installation without any dead spots (spaces)
Compatibility
In addition to the above mentioned requirements, the following parameters strongly influence the quality of the cleaning process as well as the life time of the seals:- immersion period
- temperature
- type of cleaning media
- concentration of the cleaning solution
| Material | Nitric acid 85°C, 2% | caustic soda 85°C, 3% | Aqua dest. 100°C | Steam 140°C | Sodium hypo- chlorite solution 70°C, 5% | Solution sodium hydroxide sodium- hypochlorite 70°C,3% | Solution sodium hydroxide sodium carbonate 70°C,3% | Solution hydrogen peroxide peracetic acid 50°C,3% | 3-A Sani- tary stan- dards 18-03 |
|---|---|---|---|---|---|---|---|---|---|
| PUR | + | + | + | - | + | + | + | + | Class 1,3** |
| NBR | (-) | + | +at 70°C | (-) | n.d.a. | n.d.a. | n.d.a. | n.d.a. | n.d.a. |
| H-NBR | (-) | + | + | - | n.d.a. | n.d.a. | n.d.a. | n.d.a. | n.d.a. |
| Silicone | - | (-) | + | (-) | n.d.a. | + | + | n.d.a. | n.d.a. |
| Viton® | (o) | o | o | - | o | + | + | + | Class 1 |
immersion period: 168 hours
n.d.a.: no data available
(+,o,-): n.d.a. supposed to be +, o or -
** class 1,3: passed all tests for class 1, except the temperature of exposure to product of sterilization (possible up to 100°C)
+ : resistant
o : limited resistance
- : not resistant
