- Contamination control
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Contamination control is the generic term for all activities aiming to control the existence, growth and proliferation of contamination in certain areas. Contamination control may refer to the atmosphere as well as to surfaces, to particulate matter as well as to microbes and to contamination prevention as well as to decontamination
Contamination control measures at a premier lens manufacturer (Carl Zeiss.)
Flooring in a material handling area at Pharmaceutical company Lilly, France.
Gowning area at Alcatel, London, UK.Contents
Function
The aim of all contamination control activities is to permanently ensure a sufficient level of cleanliness in controlled environments. This is accomplished by maintaining, reducing or eradicating viable and non-viable contamination for either sanitary purposes or in order to maintain an efficient rate of production.
Usage
One of the most common environments that incorporates contamination control into its standards protocol is the cleanroom. There are many preventative procedures in place within the cleanroom environment. Procedures include subjecting cleanroom staff to strict clothing regulations, and there is often a gowning room where the staff can change under sterile conditions, so as to prevent any particulate from entering from the outside environment. Certain areas in the cleanroom have more stringent measures than others. Places such as packaging areas, corridors, gowning rooms and transfer hatches incorporate strict contamination control measures in order to keep to the cleanroom standards.
Contamination control is also an important asset to laboratories in industries such as the pharmaceutical and life science sectors. Other places of use include automotive paint shops, entrances to industrial kitchens and food service providers, many manufacturing areas, and in electronic component assembly areas.
More recently contamination control has been a concern for laboratories and other sensitive environments as an effective bio-security crisis management measure. Some banks and insurance companies use contamination control products as part of their disaster management protocols. Preventative measures are put in place as preparation for potential pandemics or the proliferation of biohazards in any potential terrorist attack.
Types of contamination
Beside of particulate matter, the most common type of contamination, ions and molecules (AMC) there are many types of organism that are potentially detrimental to processes in a critical environment. Seven of the most common contaminants are:
- Aspergillus niger
- Burkholderia cepacia
- Clostridium difficile
- Escherichia coli
- Methicillin Resistant Staphylococcus aureus (MRSA)
- Pseudomonas aeruginosa
- Salmonella enteritidis
These, and many other damaging contaminants can infiltrate critical areas in a manner of ways. Particulate can enter by air, foot, or on any carrier between the external environment and inside the critical area.The effects of contamination
Contamination poses a significant risk to technical processes of experiment or production as well as to the individual. Unguarded proliferation of contamination can quickly lead to product damage, yield reduction, product recalls and other outcomes highly detrimental to businesses. A number of products over a range of industries are recalled due to ineffective contamination control systems.[1]
By this evidence it could be argued that many businesses are not adequately protecting themselves from the harmful effects of contamination, and many products over many industries are being recalled due to unsafe manufacturing processes.
Types of contamination control
Body movement causes contamination and protective clothing such as hats, cleanroom suits and face masks are basic forms of contamination control. Apart from people, the other common way for contamination to enter is on the wheels of trolleys used to transport equipment.
To prevent airborne contamination, high efficiency particulate air (HEPA) filters, airlocks and cleanroom suits are used. HEPA filtration systems used in the medical sector incorporate high-energy ultra-violet light units to kill off the live bacteria and viruses trapped by the filter media. These measures restrict the number of particulates within the atmosphere, and inhibit growth in those that are viable.
Studies by 3M show that over 80% of contamination enters the cleanroom through entrances and exits, mostly at or near floor level.[2] To combat this suitable flooring systems are used that effectively attract, retain and inhibit growth of viable organisms. Studies show that the most effective type of flooring system is one of polymer composition.[3]
Polymer mats are particularly effective due to their suppleness[4] as they allow for more contact with serration on shoes and wheels and can accommodate for more particles whilst remaining effective. An electrostatic potential adds to the effectiveness of this type of contamination control as it holds particles until being cleaned. This method of attracting and retaining particles is more effective than mats with an active adhesive coating which needs to be peeled and is often not as supple.[5][6] As long as the tack level of the mat is greater than the donor (foot or wheel), the contamination touching the surface will be removed. Very high tack surfaces pose a contamination threat because they are prone to pulling off over-shoe protection.[7] Polymeric flooring is produced to ensure a higher level of tackiness than the surfaces it comes into contact with, without causing discomfort and potentially damaging ‘stickiness’.
Main articles: Antimicrobial properties of copper and Antimicrobial copper-alloy touch surfacesCopper-alloy surfaces have natural intrinsic properties to effectively and quickly destroy microbes and are being installed in healthcare facilities and in a subway transit system as a protective public health measure in addition to regular cleanings. The United States Environmental Protection Agency (EPA) has approved the registration of 355 different antibacterial copper alloys that kill E. coli O157:H7, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus, Enterobacter aerogenes, and Pseudomonas aeruginosa.[8][9][10] The EPA has determined that when cleaned regularly, these copper alloy surfaces:
- Continuously reduce bacterial contamination, achieving 99.9% reduction within two hours of exposure;
- Kill greater than 99.9% of Gram-negative and Gram-positive bacteria within two hours of exposure;
- Deliver continuous and ongoing antibacterial action, remaining effective in killing greater than 99.9% of bacteria within two hours;
- Kill greater than 99.9% of bacteria within two hours, and continue to kill 99% of bacteria even after repeated contamination;
- Help inhibit the buildup and growth of bacteria within two hours of exposure between routine cleaning and sanitizing steps.
As a contamination control measure, EPA has approved a long list of antimicrobial copper products "with public health benefits" made from these copper alloys, such as bedrails, handrails, over-bed tables, sinks, faucets, door knobs, toilet hardware, computer keyboards, health club equipment, shopping cart handles, etc. (for a comprehensive list of products, see: Antimicrobial copper-alloy touch surfaces#Approved products).
See also
References
- ^ Emerald: Article Request - Foreign bodies cause most recalls
- ^ Dycem Ltd
- ^ The Role Of Polymeric Flooring In The Control Of Particulate
- ^ http://ask.technopharm.de/index.php5?id=1059420&Action=showProduct&bmp=10111
- ^ Cleanroom and contamination control forum
- ^ Shield Medicare - Frequent Questions
- ^ Cleanroom Technology - Current industry news and reports
- ^ http://en.wikipedia.org/wiki/Antimicrobial_properties_of_copper
- ^ http://en.wikipedia.org/wiki/Antimicrobial_copper_touch_surfaces
- ^ Copper Touch Surfaces
http://www.iest.org The Institute of Environmental Sciences and Technology (IEST)
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