Cleanliness in manufacturing is an important parameter, not only for hygiene reasons but for quality purposes as well. Hygiene is critical in food & drink, healthcare, beauty, and other service industries. Good hygiene helps:
- prevent contamination of product.
- Prevent microbial contamination.
- reduce the spread of infectious diseases.
- protect the client or consumer.
- prevent pests such as rats, flies and cockroaches being attracted to the work area.
In other industries cleaning is important to protect products and equipment. This is important to chemical, medical, electronic, and other manufacturing industries. The benefits of good cleaning are it:
- helps prevent cross-contamination.
- helps equipment run efficiently.
- creates a more pleasant working environment.
- reduces the likelihood of slips and trips.
- helps identify problems with production processes.
- protects finish on consumer goods.
With more modern cleaning products entering the market every day it can be easy to forget the basics. It can be very confusing to work out what is best with such a huge range of products available. We are going to start with the most important step in any hygiene routine, cleaning.
How clean is clean?
Before you set up a cleaning regime you need to understand why you are doing it and what you are aiming for. Depending on the situation you could be aiming for visibly clean, sterile or ISO9 cleanroom standard, or anything in between.
If you are producing consumer goods you don’t want visible stains on your products. You cannot achieve top dollar for your high-end washing machine if it has a huge greasy handprint on the side. In these cases, cleaning to a visibly clean standard is sufficient.
If you are producing or assembling delicate electronic goods, you may need to work to cleanroom standards. Here you will need to take advice on the best environment and environmental controls. You may even have to define the type of clothing your staff wear. No nylon underpants due to risk of static discharge, and no dust generating fabrics like cotton.
For chemical products you need to be careful about cross contamination especially with high purity chemicals, pharmaceuticals, and coloured products. With pharma there are already some strict cleaning standards available. For coloured products, like dyes, you may want to aim for visibly clean equipment between batches to prevent cross contamination. With chemical products you may need specialist analytical equipment, as you may not be able to see the contamination.
For medical, cosmetics and food & drink, you need to work to a hygiene standard, as you don’t want to be responsible for contaminating your product with a microorganism that causes an infectious disease. This may require a disinfecting or sterilising step.
Why should I clean first?
Even if you require a high level of cleanliness in manufacturing, there are four very good reasons for cleaning your environment, equipment, and tools thoroughly before any other step.
- It removes foreign material that is not part of the item (e.g., dust, soil, or blood). This means that microorganisms do not have readily available sources of food and shelter which they need to thrive.
- Cleaning removes a large percentage of the microorganisms that are contaminating your items. Importantly removing difficult to kill spores and prions. Reducing the number of microorganisms also makes the disinfection and sterilisation steps more effective.
- Cleaning is a must before disinfecting your items. As it means the disinfectant can then work directly on the item’s surface which is no longer shielded by dirt.
- Heat and chemical sterilising steps can ‘bake on’ dirt, making the dirt very difficult or impossible to remove. Permanently stained tools may need to be thrown away.
A bonus fifth reason is that a clean area makes your workplace a much more pleasant place to work.
Thorough cleaning is often sufficient on its own. The chemical disinfection of tools and equipment is not always necessary, it all depends on the purpose of the cleaning process and the risk to your products, clients, or consumers.
What is cleaning?
Technically, manual cleaning is the action of friction and fluidics to remove foreign material. In simpler terms friction is the physical action of scrubbing and rubbing. This breaks the connection between the dirt and the item. Fluidics is the action of the water to soften dirt and help move it away from the surface. You should be using soap and hot water as this is significantly more effective than water on its own. For stubborn dirt you may need a bit of a soak first.
Soap Is a key Ingredient of cleaning as it helps dissolve grease into the water and prevents dirt sticking back on your item. It also helps break the grasp that the dirt and microorganisms have on the tool’s surface, allowing them to be washed away.
At the end of the day, it comes down to what my gran would call ‘elbow grease’. You need to put in sufficient effort to get that dirt off. This sounds a bit silly, but you know when you have finished as your tools look clean.
What’s the right level of cleanliness in manufacturing?
This depends upon what you are trying to achieve. Are you trying to prevent the spread of infectious diseases to clients and consumers. Or preventing contamination of sensitive analytical equipment you are assembling.
When considering the spread of infectious diseases, you need to assess the risk. The risk depends upon the number of microorganisms on your product, and the infection pathways. If a clean product only encounters healthy consumers, then risk is seen as low. If your consumers are vulnerable then the risk is higher, and a higher level of cleanliness will be required.
Microbial load
If you are trying to reduce the risk of the spread of infectious diseases than the metric of cleanliness is microbial load. This is the number of microorganisms on your item.
Just to clarify, cleaning is the removal of visible dirt from your tools which removes large numbers of microorganisms. If your next hygiene step kills all of the microbial life it is called sterilisation, and this requires high temperature or harsh chemicals or other high-tech solutions. Sanitising is a term that seems to be coming more common, and this generally refers to sufficient cleaning and disinfection of equipment to acceptable levels.
The risk of contamination
Risk is the combined chance and impact of contaminating your product. This is a combination of the likelihood and severity. Likelihood is a function of how dirty your assembly process is, the dirtier the environment the more likely you are to contaminate your product. The severity is the magnitude of the negative impact, for example a spot of dust could cause a microchip to fail.
So, quantifying the cleanliness in manufacturing is critical. To find out how clean your environment needs to be, you can consult the relevant industrial standards. If these are not available you can work backwards from product quality, to calculate the allowable contamination of product, and hence determine the required cleanliness of your processes.
Chemical solutions
If you are having issues with contamination, and need to improve product quality, then give us a call for a chat about your approach to improving cleanliness. We can help you identify contamination risks, define cleanliness levels, and help develop robust controls. If you are interested in learning more about our chemical solutions service, then check out our webpage.
References
(Hoffman 2004) Hoffman, P., Bradley, C. Ayliffe, G. 2004, Disinfection in Healthcare, third ed. Health Protection Agency
(CDC 2008) Centres for Disease Control and Prevention, Guidelines for Disinfection and Sterilization in Healthcare Facilities, 2008
Photograph from National Institute of Standards and Technology