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.
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.[ citation needed ]
One of the most common environments that incorporates contamination control into its standards protocol is the cleanroom. There are many preventive procedures in place within a cleanroom environment. They include subjecting cleanroom staff to strict clothing regulations, and there is often a gowning room where the staff can change clothes under sterile conditions so as to prevent any particulates from entering from the outside environment. Certain areas in the cleanroom have more stringent measures than others: packaging areas, corridors, gowning rooms and transfer hatches incorporate strict contamination control measures in order to maintain cleanroom standards.[ citation needed ]
Contamination control is also an important asset for industrial laboratories in 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 electronic component assembly areas.[ citation needed ]
More recently, effective contamination control has been a concern for laboratories and other sensitive environments as a bio-security crisis management measure. Some banks and insurance companies use contamination control products as part of their disaster management protocols. Preventive measures are devised as preparation for combating potential pandemics or the proliferation of biohazards in any potential terrorist attack.
Besides particulate matter such as ions and molecules, the most common types of contamination are:[ citation needed ]
Many types organisms are potentially detrimental to processes in a critical environment. Seven of the most common contaminants are:
These and many other damaging contaminants can infiltrate critical areas in many ways. Particulates can enter by air, or on the feet of any carrier moving between the external environment and inside the critical area, for example.
Contamination poses a significant risk to technical processes, experiments, or production activities, as well as to the individuals involved. Unguarded proliferation of contamination can quickly lead to product damage, yield reduction, product recalls and other outcomes highly detrimental to business. Products in several industries are recalled due to ineffective contamination control systems. [1]
Based on this evidence it could be argued that many businesses are not adequately protecting themselves from the harmful effects of contamination, and many products in many industries are being recalled due to unsafe manufacturing processes.[ citation needed ]
Body movement causes contamination, and protective clothing such as hats, cleanroom suits and face masks are accordingly basic items of contamination control. Apart from people, another 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 ultraviolet light units to kill the live bacteria and viruses trapped by the filter media. These measures restrict the number of particulates within the atmosphere and inhibit the growth of those that are viable.[ citation needed ]
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 problem, suitable flooring systems are used that effectively attract, retain and inhibit the 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 serrations on shoes and wheels and can accommodate more particles while still remaining effective. An electrostatic potential adds to the effectiveness of this type of contamination control as it enables particles to be retained until the flooring is 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's (such as a foot or a wheel), the contamination touching the surface will be removed. Very high tack surfaces pose a contamination threat because they are prone to pulling off overshoe 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'.
Copper-alloy surfaces have intrinsic properties which effectively and quickly destroy microbes and they are being installed in healthcare facilities and in a subway transit system as a protective public health measure in addition to regular cleaning. 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] The EPA has determined that when cleaned regularly, these copper alloy surfaces:
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 bed rails, handrails, over-bed tables, sinks, faucets, door knobs, toilet hardware, computer keyboards, health club equipment, shopping cart handles, etc.[ citation needed ] (For a comprehensive list of products, see: Antimicrobial copper-alloy touch surfaces § Approved products).
A cleanroom or clean room is an engineered space that maintains a very low concentration of airborne particulates. It is well isolated, well controlled from contamination, and actively cleansed. Such rooms are commonly needed for scientific research and in industrial production for all nanoscale processes, such as semiconductor manufacturing. A cleanroom is designed to keep everything from dust to airborne organisms or vaporised particles away from it, and so from whatever material is being handled inside it.
A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than sterilization, which is an extreme physical or chemical process that kills all types of life. Disinfectants are generally distinguished from other antimicrobial agents such as antibiotics, which destroy microorganisms within the body, and antiseptics, which destroy microorganisms on living tissue. Disinfectants are also different from biocides—the latter are intended to destroy all forms of life, not just microorganisms. Disinfectants work by destroying the cell wall of microbes or interfering with their metabolism. It is also a form of decontamination, and can be defined as the process whereby physical or chemical methods are used to reduce the amount of pathogenic microorganisms on a surface.
Radioactive contamination, also called radiological pollution, is the deposition of, or presence of radioactive substances on surfaces or within solids, liquids, or gases, where their presence is unintended or undesirable.
HEPA filter, also known as a high-efficiency particulate arresting filter, is an efficiency standard of air filters.
An antimicrobial is an agent that kills microorganisms (microbicide) or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals are used against fungi. They can also be classified according to their function. The use of antimicrobial medicines to treat infection is known as antimicrobial chemotherapy, while the use of antimicrobial medicines to prevent infection is known as antimicrobial prophylaxis.
An air purifier or air cleaner is a device which removes contaminants from the air in a room to improve indoor air quality. These devices are commonly marketed as being beneficial to allergy sufferers and asthmatics, and at reducing or eliminating second-hand tobacco smoke.
Ultra-low particulate air (ULPA) is a type of air filter. A ULPA filter can remove from the air at least 99.999% of dust, pollen, mold, bacteria and any airborne particles with a minimum particle penetration size of 120 nanometres. A ULPA filter can remove—to a large extent but not 100%—oil smoke, tobacco smoke, rosin smoke, smog, and insecticide dust. It can also remove carbon black to some extent. Some fan filter units incorporate ULPA filters. The EN 1822 and ISO 29463 standards may be used to rate ULPA filters.
Infection prevention and control is the discipline concerned with preventing healthcare-associated infections; a practical rather than academic sub-discipline of epidemiology. In Northern Europe, infection prevention and control is expanded from healthcare into a component in public health, known as "infection protection". It is an essential part of the infrastructure of health care. Infection control and hospital epidemiology are akin to public health practice, practiced within the confines of a particular health-care delivery system rather than directed at society as a whole.
A particle counter is used for monitoring and diagnosing particle contamination within specific clean media, including air, water and chemicals. Particle counters are used in a variety of applications in support of clean manufacturing practices, industries include: electronic components and assemblies, pharmaceutical drug products and medical devices, and industrial technologies such as oil and gas.
Air showers are specialized enclosed antechambers which are incorporated as entryways of cleanrooms and other controlled environments to reduce particle contamination. Air showers utilize high-pressure, HEPA- or ULPA-filtered air to remove dust, fibrous lint and other contaminants from personnel or object surfaces. The forceful "cleansing" of surfaces before entering clean environments reduces the number of airborne particulates introduced.
Pharmaceutical microbiology is an applied branch of microbiology. It involves the study of microorganisms associated with the manufacture of pharmaceuticals e.g. minimizing the number of microorganisms in a process environment, excluding microorganisms and microbial byproducts like exotoxin and endotoxin from water and other starting materials, and ensuring the finished pharmaceutical product is sterile. Other aspects of pharmaceutical microbiology include the research and development of anti-infective agents, the use of microorganisms to detect mutagenic and carcinogenic activity in prospective drugs, and the use of microorganisms in the manufacture of pharmaceutical products like insulin and human growth hormone.
The Institute of Environmental Sciences and Technology (IEST) is a non-profit, technical society where professionals who impact controlled environments connect, gain knowledge, receive advice, and work together to create industry best practices. The organization uniquely serves environmental test engineers, qualification engineers, cleanroom professionals, those who work in product testing and evaluation, and others who work across a variety of industries, including: acoustics, aerospace, automotive, biotechnology/bioscience, climatics, cleanroom operations/design/equipment/certification, dynamics, filtration, food processing, HVAC design, medical devices, nanotechnology, pharmaceutical, semiconductors/microelectronics, and shock/vibration. Information on ISO 14644 and ISO 14698 standards can be found through this organization.
ISO 14644 Standards were first formed from the US Federal Standard 209E Airborne Particulate Cleanliness Classes in Cleanrooms and Clean Zones. The need for a single standard for cleanroom classification and testing was long felt. After ANSI and IEST petitioned to ISO for new standards, the first document of ISO 14644 was published in 1999, ISO 14644-1.
Aerobiological engineering is the science of designing buildings and systems to control airborne pathogens and allergens in indoor environments. The most-common environments include commercial buildings, residences and hospitals. This field of study is important because controlled indoor climates generally tend to favor the survival and transmission of contagious human pathogens as well as certain kinds of fungi and bacteria.
A biosafety cabinet (BSC)—also called a biological safety cabinet or microbiological safety cabinet—is an enclosed, ventilated laboratory workspace for safely working with materials contaminated with pathogens requiring a defined biosafety level. Several different types of BSC exist, differentiated by the degree of biocontainment they provide. BSCs first became commercially available in 1950.
Copper and its alloys are natural antimicrobial materials. Ancient civilizations exploited the antimicrobial properties of copper long before the concept of microbes became understood in the nineteenth century. In addition to several copper medicinal preparations, it was also observed centuries ago that water contained in copper vessels or transported in copper conveyance systems was of better quality than water contained or transported in other materials.
Antimicrobial copper-alloy touch surfaces can prevent frequently touched surfaces from serving as reservoirs for the spread of pathogenic microbes. This is especially true in healthcare facilities, where harmful viruses, bacteria, and fungi colonize and persist on doorknobs, push plates, handrails, tray tables, tap (faucet) handles, IV poles, HVAC systems, and other equipment. These microbes can sometimes survive on surfaces for more than 30 days.
An antimicrobial surface is coated by an antimicrobial agent that inhibits the ability of microorganisms to grow on the surface of a material. Such surfaces are becoming more widely investigated for possible use in various settings including clinics, industry, and even the home. The most common and most important use of antimicrobial coatings has been in the healthcare setting for sterilization of medical devices to prevent hospital associated infections, which have accounted for almost 100,000 deaths in the United States. In addition to medical devices, linens and clothing can provide a suitable environment for many bacteria, fungi, and viruses to grow when in contact with the human body which allows for the transmission of infectious disease.
A fan filter unit (FFU) is a type of motorized air filtering equipment. It is used to supply purified air to cleanrooms, laboratories, medical facilities or microenvironments by removing harmful airborne particles from recirculating air. The units are installed within the system's ceiling or floor grid. Large cleanrooms require a proportionally large number of FFUs, which in some cases may range from several hundred to several thousand. Units often contain their own pre-filter, HEPA filter and internally controllable fan air distribution.
Diving equipment may be exposed to contamination in use and when this happens it must be decontaminated. This is a particular issue for hazmat diving, but incidental contamination can occur in other environments. Personal diving equipment shared by more than one user requires disinfection before use. Shared use is common for expensive commercial diving equipment, and for rental recreational equipment, and some items such as demand valves, masks, helmets and snorkels which are worn over the face or held in the mouth are possible vectors for infection by a variety of pathogens. Diving suits are also likely to be contaminated, but less likely to transmit infection directly.