Autoclave (aliza bibi)

autoclave: definition, introduction, working principle, functions

1. TOPIC : AUTOCLAVE BY : ALIZA BIBI

2. AUTO CLAVE An autoclave is a machine used to carry out industrial and scientific processes requiring elevated temperature and pressure in relation to ambient pressure/temperature. Autoclaves are used in medical applications to perform sterilization and in the chemical industry to cure coatings and vulcanize rubber and for hydrothermal synthesis. Industrial autoclaves are used in industrial applications, especially in the manufacturing of composites.

3. AUTOCLAVE

4. AUTOCLAVE DEFINITION An autoclave is a machine that provides a physical method of sterilization by killing bacteria, viruses, and even spores present in the material put inside of the vessel using steam under pressure. Autoclave sterilizes the materials by heating them up to a particular temperature for a specific period of time. The autoclave is also called a steam sterilizer that is commonly used in healthcare facilities and industries for various purposes. The autoclave is considered a more effective method of sterilization as it is based on moist heat sterilization.

5. HISTORY OF AUTOCLAVE The autoclave was invented in 1879 by Charles Chamberland, but the concept of using steam in an enclosed space for the purpose of preventing sickness had already existed since 1679. Unlike most processes going on in today’s laboratories and hospitals, sterilization has occurred using very much the same principles and methods for the last 150 years. Most advances in autoclave technology since that time have revolved around either keeping better track of the process of sterilization to better guarantee the safety of the users or creating new types of sterilization cycles. Another element of sterilization that hasn’t changed over time is the use of steam as a sterilizing agent.

6. AUTO CLAVE USES Many autoclaves are used to sterilize equipment and supplies by subjecting them to pressurized saturated steam at 121 °C (250 °F) for around 15–20 minutes depending on the size of the load and the contents. The autoclave was invented by Charles Chamberland in 1879, although a precursor known as the steam digester was created by Denis Papin in 1679. The name comes from Greek auto-, ultimately meaning self, and Latin clavis meaning key, thus a self-locking device.

7. USES OF AUTO CLAVE Sterilization autoclaves are widely used in microbiology, medicine, podiatry, tattooing, body piercing, veterinary medicine, mycology, funerary practice, dentistry, and prosthetics fabrication. They vary in size and function depending on the media to be sterilized and are sometimes called retort in the chemical and food industries. Typical loads include laboratory glassware, other equipment and waste, surgical instruments, and medical waste.

8. USES OF AUTO CLAVE A notable recent and increasingly popular application of autoclaves is the pre-disposal treatment and sterilization of waste material, such as pathogenic hospital waste. Machines in this category largely operate under the same principles as conventional autoclaves in that they are able to neutralize potentially infectious agents by using pressurized steam and superheated water. A new generation of waste converters is capable of achieving the same effect without a pressure vessel to sterilize culture media, rubber material, gowns, dressings, gloves, etc. It is particularly useful for materials which cannot withstand the higher temperature of a hot air oven.

9. USES OF AUTO CLAVE Autoclaves are also widely used to cure composites, especially for melding multiple layers without any voids that would decrease material strength, and in the vulcanization of rubber. The high heat and pressure that autoclaves generate help to ensure that the best possible physical properties are repeatable. Manufacturers of spars for sailboats have autoclaves well over 50 feet (15 m) long and 10 feet (3 m) wide, and some autoclaves in the aerospace industry are large enough to hold whole airplane fuselages made of layered composites.

10. USES OF AUTO CLAVE Other types of autoclaves are used to grow crystals under high temperatures and pressures. Synthetic quartz crystals used in the electronics industry are grown in autoclaves. Packing of parachutes for specialist applications may be performed under vacuum in an autoclave, which allows the chutes to be warmed and inserted into their packs at the smallest volume.

11. AIR REMOVAL It is very important to ensure that all of the trapped air is removed from the autoclave before activation, as trapped air is a very poor medium for achieving sterility. Steam at 134 °C (273 °F) can achieve a desired level of sterility in three minutes, in contrast to hot air at 160 °C (320 °F), which can take two hours to achieve the same sterility.

12. METHODS OF AIR REMOVAL GRAVITY TYPE STEAM PULSING VACCUMM PUMPS SUPERATMOSPHERIC CYCLES SUBATMOSPHERIC CYCLES

13. METHODS OF AIR REMOVAL Downward displacement (or gravity-type): As steam enters the chamber, it fills the upper areas first as it is less dense than air. This process compresses the air to the bottom, forcing it out through a drain which often contains a temperature sensor. Only when air evacuation is complete does the discharge stop. Flow is usually controlled by a steam trap or a solenoid valve, but bleed holes are sometimes used. As the steam and air mix, it is also possible to force out the mixture from locations in the chamber other than the bottom. Steam pulsing: air dilution by using a series of steam pulses, in which the chamber is alternately pressurized and then depressurized to near atmospheric pressure.

14. METHODS OF AIR REMOVAL Vacuum pumps: a vacuum pump sucks air or air/steam mixtures from the chamber. Superatmospheric cycles: achieved with a vacuum pump. It starts with a vacuum followed by a steam pulse followed by a vacuum followed by a steam pulse. The number of pulses depends on the particular autoclave and cycle chosen. Subatmospheric cycles: similar to the superatmospheric cycles, but chamber pressure never exceeds atmospheric pressure until they pressurize up to the sterilizing temperature.

15. AIR REMOVAL

16. IN MEDICINE A medical autoclave is a device that uses steam to sterilize equipment and other objects. This means that all bacteria, viruses, fungi, and spores are inactivated. However, prions, such as those associated with Creutzfeldt–Jakob disease, and some toxins released by certain bacteria, such as Cereulide, may not be destroyed by autoclaving at the typical 134 °C for three minutes or 121 °C for 15 minutes.[citation needed] Although a wide range of archaea species, including Geogemma barosii, can survive and even reproduce at temperatures above 121 °C, none of them are known to be infectious or otherwise pose a health risk to humans; in fact, their biochemistry is so different from our own and their multiplication rate is so slow that microbiologists need not worry about them.

17. IN MEDICINE

18. IN MEDICINE Autoclaves are found in many medical settings, laboratories, and other places that need to ensure the sterility of an object. Many procedures today employ single-use items rather than sterilizable, reusable items. This first happened with hypodermic needles, but today many surgical instruments (such as forceps, needle holders, and scalpel handles) are commonly single-use rather than reusable items (see waste autoclave). Autoclaves are of particular importance in poorer countries due to the much greater amount of equipment that is re-used. Providing stove-top or solar autoclaves to rural medical centers has been the subject of several proposed medical aid missions.

19. IN MEDICINE Because damp heat is used, heat-labile products (such as some plastics) cannot be sterilized this way or they will melt. Paper and other products that may be damaged by steam must also be sterilized another way. In all autoclaves, items should always be separated to allow the steam to penetrate the load evenly. Autoclaving is often used to sterilize medical waste prior to disposal in the standard municipal solid waste stream. This application has become more common as an alternative to incineration due to environmental and health concerns raised because of the combustion by-products emitted by incinerators, especially from the small units which were commonly operated at individual hospitals. Incineration or a similar thermal oxidation process is still generally mandated for pathological waste and other very toxic or infectious medical waste.

20. IN MEDICINE In dentistry, autoclaves provide sterilization of dental instruments. In most of the industrialized world medical-grade autoclaves are regulated medical devices. Many medical-grade autoclaves are therefore limited to running regulator-approved cycles. Because they are optimized for continuous hospital use, they favor rectangular designs, require demanding maintenance regimens, and are costly to operate. (A properly calibrated medical-grade autoclave uses thousands of gallons of water each day, independent of task, with correspondingly high electric power consumption.)

21. IN MEDICINE

22. IN RESEARCH Most medical-grade autoclaves are inappropriate for research tasks. General-use non-medical (often called "research-grade") autoclaves are increasingly used in a wide range of education, research, and industrial settings (including biomedical research) where efficiency, ease-of-use, and flexibility are at a premium. Research-grade autoclaves may be configured for "pass-through" operation. This makes it possible to maintain absolute isolation between "clean" and potentially contaminated work areas. Pass-through research autoclaves are especially important in BSL-3 or BSL-4 facilities.

23. IN RESEARCH Research-grade autoclaves—which are not approved for use in sterilizing instruments that will be directly used on humans—are primarily designed for efficiency, flexibility, and ease-of-use. They display a wide range of designs and sizes, and are frequently tailored to their use and load type. In 2016, the Office of Sustainability at the University of California, Riverside (UCR) conducted a study of autoclave efficiency in their genomics and entomology research labs, tracking several units' power and water consumption. They found that, even when functioning within intended parameters, the medical-grade autoclaves used in their research labs were each consuming 700 gallons of water and 90 kWh of electricity per cycle (1,134MWh of electricity and 8.8 million gallons of water total). UCR's research-grade autoclaves performed the same tasks with equal effectiveness, but used 83% less energy and 97% less water.

24. IN RESEARCH

25. QUALITY ASSURANCE There are physical, chemical, and biological indicators that can be used to ensure that an autoclave reaches the correct temperature for the correct amount of time. If a non-treated or improperly treated item can be confused for a treated item, then there is the risk that they will become mixed up, which, in some areas such as surgery, is critical. Chemical indicators on medical packaging and autoclave tape change color once the correct conditions have been met, indicating that the object inside the package, or under the tape, has been appropriately processed. Autoclave tape is only a marker that steam and heat have activated the dye. The marker on the tape does not indicate complete sterility. A more difficult challenge device, named the Bowie-Dick device after its inventors, is also used to verify a full cycle. This contains a full sheet of chemical indicator placed in the center of a stack of paper. It is designed specifically to prove that the process achieved full temperature and time required for a normal minimum cycle of 134 °C for 3.5–4 minutes.

26. QUALITY ASSURANCE To prove sterility, biological indicators are used. Biological indicators contain spores of a heat-resistant bacterium, Geobacillus stearothermophilus. If the autoclave does not reach the right temperature, the spores will germinate when incubated and their metabolism will change the color of a pH-sensitive chemical. Some physical indicators consist of an alloy designed to melt only after being subjected to a given temperature for the relevant holding time. If the alloy melts, the change will be visible.[citation needed] Some computer-controlled autoclaves use an F0 (F-nought) value to control the sterilization cycle. F0 values are set for the number of minutes of sterilization equivalent to 121 °C (250 °F) at 100 kPa (15 psi) above atmospheric pressure for 15 minutes. Since exact temperature control is difficult, the temperature is monitored, and the sterilization time adjusted accordingly.

27. HOW DOES A LABORATORY AUTOCLAVE WORKS? Steam sterilization is, and should be, an important process within every laboratory. This process is performed in a steam sterilizer and this article will explore how a sterilizer works, the sterilization process, why we do it, and its origins. The following guide outlines not only the history of steam sterilization, but also explains how it works and why it’s such a crucial component to maintaining a clean and sterile lab.

28. STEAM STERILIZER The terms Autoclave and Steam Sterilizer are essentially synonymous and often used interchangeably. “Autoclave” is used more often in laboratory settings, while “Sterilizer” is more commonly heard in hospitals or pharmaceutical settings.

29. STEAM STERILIZER The autoclave, a device that is ubiquitous in almost all scientific settings, is a device that uses steam heat to kill any microbial life that may be present on a contaminated Load. Any load (also referred to as Goods) that has undergone a full sterilization cycle are considered to be sterile and can be used without fear of introducing foreign microorganisms into a sensitive environment — that environment being a laboratory, hospital operating room, food production facility, etc. Different types of goods must be sterilized for different times, at different temperatures. Some autoclaves contain features that others do not, such as vacuum functions, special cycles, and integral electric boilers.

30. STEAM STERILIZER

31. WHY STEAM? In order to kill a cell through heat, its temperature must be raised to the point where the proteins in the cell wall break down and coagulate. Steam is a very efficient medium for transferring heat, therefore it is an excellent way to destroy microbes. Air, on the other hand, is a very inefficient way to transfer heat/energy when compared to steam because of a concept called the Heat of Evaporation. To bring one liter of water to the boiling point (100˚C) requires 80kcal of heat energy. Converting that liter of water to steam requires 540kcal — this means that steam at 100˚C contains seven times as much energy as water at 100˚C. It’s that energy that makes steam so much more efficient at destroying microorganisms. When steam encounters a cooler object, it condenses into water and transfers all the energy that was required to boil it directly into it, heating it up far more efficiently than air at similar temperatures. In short, steam is how we achieve sterility in the sterilization process.

32. WHAT IS STERILITY? Most people have a working understanding that sterile goods are free of microorganisms and are safe to use in medical, food production, or other settings where the presence of germs would be a significant safety hazard. Exactly how many microorganisms are going to be left alive over time at a fixed temperature is expressed by a logarithmic curve, a function that approaches, but never reaches zero

33. STERILITY GRAPH

34. HOW DOES AN AUTOCLAVE WORKS? Whether it’s a small tabletop autoclave or a room-sized bulk autoclave, all autoclaves operate on similar principles that they share with a common kitchen pressure cooker — the door is locked to form a sealed chamber, and all air within the chamber is replaced by steam. The steam is then pressurized to reach the desired sterilization temperature and time, before exhausting the steam and allowing the goods to be removed. Here are the various phases of a sterilization cycle.

35. PHASES OF STERILIZATION CYCLES 1. Purge Phase: Steam flows through the sterilizer beginning the process of displacing the air; temperature and pressure ramp slightly to a continuous flow purge. 2. Exposure (Sterilization) Phase: During this phase, the autoclaves’ control system is programmed to close the exhaust valve causing the interior temperature and pressure to ramp up to the desired setpoint. The program then maintains the desired temperature (dwells) until the desired time is reached. 3. Exhaust Phase: The pressure is released from the chamber through an exhaust valve and the interior is restored to ambient pressure, although contents remain relatively hot.

36. EXHAUST PHASE

37. COMPONENTS OF ATOCLAVE CHAMBER CONTROL SYSTEMS THERMOSTATIC TRAP SAFETY VALUE WASTE WATER COOLING MECHANISM VACCUMM SYSTEM STEAM GENERATOR

38. COMPONENTS OF AUTOCLAVE

39. CHAMBER The chamber is the primary component of a steam autoclave, consisting of an inner chamber and outer jacket. Laboratory and hospital autoclaves are constructed with “jacketed” chambers where the jacket is filled with steam, reducing the time that sterilization cycles take to complete and reducing condensation within the chamber. In the U.S., every autoclave chamber is inspected and tagged with an American Society of Mechanical Engineers (ASME) name plate that includes a National Boiler number. Manufacturers are required to hydrostatically test each chamber and apply the ASME name plate, before the autoclave can be put to use. This inspection and ASME name plate are crucial indicators of a properly functioning autoclave. Lab and hospital autoclave chambers can vary in size (from 100L to 3,000L). Chambers are typically constructed of 316L or Nickel-Clad (for inner chambers) and 316L, 304L, or Carbon Steel (for outer jackets).

40. CONTROL SYSTEM All modern autoclaves are equipped with a controller interface, not unlike your microwave or oven. Autoclave control systems are, however, a bit more sophisticated and complicated than those of your household appliance. A sterilization cycle follows a software “recipe” that takes the process through a series of phases that involve the opening and closing of valves and components in a specific sequence. Therefore, all autoclaves will require some form of controls, whether those be as simple as a “push button” system with a microprocessor or as complex as a Programmable Logic Controller with color touch screen.

41. THERMOSTATIC TRAP All autoclaves will feature some form of thermostatic trap or steam trap, a device designed to allow air and water (condensate) to escape from the chamber. Although various types of traps can be used in a steam delivery system/steam autoclave, they all perform the same function —removing condensate while allowing the passage of dry steam. Most often, steam traps are temperature sensitive valves that close when heated past a certain setpoint. Thermostatic traps are a critical component of any properly designed autoclave.

42. SAFETY VALVE All autoclaves operate under elevated pressures (14-45 psig), therefore, must be manufactured with an incredibly robust construction and fitted with a number of safety features and devices to ensure that they present no danger to users. One of these safety devices is the safety valve. This is the final fail-safe device for the pressure vessel should all electronic controls fail. It is imperative that the safety valve is inspected, tested and verified to be in proper working condition based on the recommendation of the sterilizer and/or valve manufacturer as well as local inspection and insurance agencies.

43. WASTE WATER COOLING MECHANISM Most autoclaves are equipped with a system to cool the effluent before it enters the drain piping. Many municipalities and buildings do not allow effluent above 140˚F to enter the floor drain. In order to avoid damage to the facility’s drain piping, the steam must be cooled before it is finally sent down the drain. The simplest, and oldest, method of cooling the steam is to mix it with additional cold tap water, but the amount of water required can make autoclaves the single biggest contributor to a building’s water use. Some autoclaves come equipped with systems designed to cut down, or even eliminate, this water consumption.

44. VACCUMM SYSTEM The primary concern for ensuring sterilization is making certain that all the air inside the chamber is replaced with steam. Certain commonly sterilized goods, particularly porous materials like animal bedding or cloth, or containers with small openings like large flasks or goods in plastic bags, tend to retain air pockets when the autoclave only relies on displacing the air by pushing steam into the chamber. If an air pocket is present during the cycle, any microorganisms within that pocket will survive and the goods will not be sterile. For this reason, many sterilizers will include a vacuum system. Not only does this allow you to forcibly remove air by pulling a vacuum on the chamber before a cycle (also known as pre-vacuum), it also helps the user by pulling a vacuum after the cycle (also known as post-vacuum) to remove the steam remaining in the chamber and dry off the goods inside the autoclave.

45. STEAM GENERATOR The most common steam source for a laboratory autoclave is from a central “house” boiler. However, when house steam is not available or is insufficient for the autoclave, one must resort to an electric steam generator (also known as a boiler). These boilers typically sit integral (i.e. underneath the chamber) to the autoclave and utilize electric heating elements to heat water and generate steam. For further information on steam sources check out this comprehensive guide.

46. STEAM GENERATOR

47. STERILIATION CYCLE In general, there are four standard sterilization cycles: Gravity Pre-Vacuum Liquids Flash (also known as Immediate Use).

48. STERILIZATION CYCLE Additionally, some autoclaves have the capability to perform specialty cycles aimed at avoiding damage to delicate goods which may need to be sterilized, but for which the normal fast changes in temperature and pressure would damage or destroy expensive products. These include much longer cycles at lower temperatures, steam-air mix cycles with special pressure controls to avoid breaking sealed test tubes or cycles using special instrumentation to ensure full sterilization temperature is achieved.

49. STERILIZATION CYCLE

50. AUTOCLAVE MEDIA Your choice of an autoclave system largely depends on your autoclave media, ie. the items to be sterilized. Overall, steam sterilization is highly dependable, effective, fast, and non-toxic, and offers an inexpensive way to rapidly heat and penetrate the chamber’s contents, including appropriately contained liquids. However, this method cannot sterilize powders or oils, and can only work with heat and moisture-resistant goods. Keeping this in mind, below is a summary of the primary types of media used by gravity and vacuum-autoclave types.

51. NON-POROUS ITEMS Gravity autoclaves are appropriate for sterilizing non-porous items (i.e. those with a hard surface): Most metals, particularly stainless steel surgical instruments and lab utensils Polypropylene Pyrex® or Type I borosilicate glassware Biohazard waste Unwrapped goods

52. POROUS ITEMS Vacuum (pre and post) are appropriate for sterilizing large or porous items: Media solutions in appropriate containers, such as tissue culture flasks with loose caps for a steam autoclave cycle Pipette tips and other high-density polyethylene products, such as syringes Wrapped dry items that can trap air Animal cages and bedding

53. CHOOSING AN AUTOCLAVE Choosing the right autoclave for your purposes requires you to not only assess the type of media to autoclave, but also throughput capacity, available lab space, and access to utilities including electricity (with proper power output), water and house steam. Due to the simplicity of the gravity-displacement mechanism, which requires an autoclaving chamber, a heating mechanism, intake and exhaust valves, there is great flexibility in design for gravity autoclaves, including front and top-loading types.

54. TOP-LOADING TYPE AUTOCLAVE The top-loading type autoclave is particularly advantageous, as it allows for maximum loading space, minimum floor space requirement and does not require any building steam connection, as the vertical chamber design allows for water to rest at the bottom, which in turn is turned into steam through a heating element located at the bottom. Note that many autoclaves on the market, especially compact top-loading autoclaves often require no more than access to the proper electrical outlet type and enough space to place your autoclave.

55. TOP LOADER TYPE AUTOCLAVE

56. HIGH ALTITUDE AUTOCLAVE Gravity autoclaves are also particularly advantageous when used in geographical areas of high humidity or higher altitudes as they consistently retain the relationship between pressure and heat within the autoclave chamber and overcome differences in boiling points at higher altitudes by opening and closing the exhaust valve. Known as high altitude autoclaves, their functions allow for proper sterilization to occur in laboratories and hospitals located in markets with high altitude terrains.

57. HIGH ALTITUDE AUTCLAVE

58. SIZE OF AUTOCLAVE Regarding the size of your autoclave, to limit energy use and costs especially for smaller labs, it is important to buy the proper size autoclave that will accommodate the equipment that needs sterilizing, while not going overcapacity. For this, several autoclaves range between 50 L and 70 L, which tend to strike a good balance between relatively high capacity and low energy use.

59. AUTOCLAVE CLASSES The autoclave is a device used to sterilize reusable medical or cosmetic tools. We distinguish 3 classes of autoclaves: CLASS N AUTOCLAVE CLASS S AUTOCLAVE CLASS B AUTOCLAVE How do they differ from each other, what is their purpose and what autoclave to choose to be suitable for the type of services we provide?

60. CLASS N AUTOCAVE Class N autoclave is the lowest class device. According to European standard EN 13060, since 2004 it can be used only as an auxiliary unit. Sterilizer of this class does not have a vacuum pump (which is present in higher class autoclaves), so only instruments with a solid structure can be sterilized within such device. It is also not possible to sterilize hollow or porous cartridges or sterilize items in packages. Class N sterilizers also do not have an effective drying option, unlike more advanced autoclaves.

61. CLASS S AUTOCLAVE Class S autoclave is an intermediate class between N and B. Within such device we can sterilize more complex instruments, B type batches, except for instruments of capillary construction (A type batches). Class S allows the sterilization of single-packed, multilayer packed and more massive instruments, which cannot be sterilized in class N autoclaves. Autoclaves of this class have a vacuum pump, which makes it possible to completely remove the air from the chamber before starting the sterilization process. However, only a single-stage pre-vacuum is used here; it is less effective than the vacuum used in class B autoclaves.

62. CLASS B AUTOCLAVE Class B autoclaves are the most advanced steam sterilizers. These are certified MEDICAL DEVICES USED IN BEAUTY PARLOURS, tattoo studios, private dental parlours, even in hospitals and large clinics. They also meet all the sanitary-epidemiological requirements. They can sterilize all types of batches, even the most complex ones. Class B autoclave, thanks to fractionated pre-vacuum, completely removes air from the chamber. It is the most effective modern technique of sterilization of all types of tools.

63. HOW TO CHOOSE AN AUTOCLAVE? WHICH PURPOSE WILL IT SERVE? AUTOCLAVE CAPACITY NOISE LEVEL WARRANTY AND SERVICE DESIGN DURATION OF STERILIZATION PROCESS COLLECTING DATA ON STERILIZATION PROCESS

64. WHICH PURPOSE WILL IT SERVE? It is essential to ensure sterilization at every place where reusable tools are used. That is why every such place should have an autoclave, preferably a class B device which is the most versatile model. B class autoclave makes possible to sterilize instruments of any design (type A and B batches), both unpackaged and packaged. In addition, class B autoclaves ensure full safety and effectiveness of sterilization process. Remember that only sterilized instruments provide protection against infection with diseases such as hepatitis B and C, HIV and diseases caused by Candida fungi.

65. AUTOCLAVE CAPACITY Enbio company offers the following models of its autoclaves: Enbio S, Enbio Pro and Enbio S Black. Enbio S and Enbio S Black (differing only in colour) are the smallest autoclaves available on the market (25 cm wide x 16 cm high x 56 cm long). They are also the fastest on the market – the entire sterilization process takes only 7 minutes. Such short time of sterilization makes possible to carry it out even between one treatment and another. The volume of the process chamber is 2,7 liters. Such capacity allows for the simultaneous sterilization of up to 8 packages of instruments. Such an autoclave can be used in beauty parlour, podiatry parlour, tattoo/piercing studio, as well as in smaller private medical clinics. Enbio PRO is a larger autoclave model. It has a much larger process chamber – its volume is 5,3 litres. It will accommodate all popular implant cassettes. Its size allows for simultaneous sterilization of up to 16 tool packs, which is twice more than for Enbio S.

66. NOISE LEVEL Enbio autoclaves are changing the philosophy of work – they are extremely quiet and compact. These are very important qualities, because working device would be heard every day. It is therefore important that autoclave is not inconvenient for employees and customers. The Enbio S and Enbio Pro autoclaves provide acoustic comfort at work – they produce less noise than popular coffee machines (42 dB(A)).

67. WARRANTY AND SERVICE The autoclave is a device that has to be used every day, because instrument sterilization has to be carried out continuously. The broken device makes sterilization process impossible to carry out which cannot happen. That’s why Enbio autoclaves have 2 year door-to-door warranty. 24/7 service is also available. In case of a device failure, a replacement device is sent or the new one is given (as long as it´s within warranty, it´s a new device, not replacement).

68. DESIGN In past autoclaves were not very aesthetically pleasing devices and they were taking up much space. These days are gone though. Enbio autoclaves are not only the highest quality devices – they also make an interesting, pleasing to the eye, integral part of parlour equipment. It is important especially for small salons and parlours. Thanks to its compact dimensions, the Enbio S autoclave can be even placed on a standard worktop. What's more, its unprecedented design was awarded in the international design competition RedDot. The sterilizers are also available in many colours – white, black, blue, yellow, pink and green. That’s why they fit into the decor of every parlour or salon.

69. DURATION OF STERILIZATION PROCESS It is known that a larger autoclave needs a little more time to sterilize the tools than a smaller one, but in both cases it is a relatively short process. The Enbio S autoclave has 3 working programs. In the 134°C FAST program, sterilization itself takes 3,5 minutes and a whole process’ total duration is only 7 minutes. The standard 134°C program, which also includes a drying stage, takes 15 minutes (with sterilization process taking only 4 minutes and drying – 3 minutes). The 121°C program, the longest one, takes 30 minutes, including the drying stage. The Enbio Pro autoclave also offers 3 programs with lengths of 10, 18 and 31 minutes. Each of them is designed for different types of instruments. However, in each case the sterilization time is short and does not hinder the admission of subsequent patients – it is possible to sterilize instruments on an ongoing basis.

70. COLLECTING DATA It is the responsibility of each parlour to keep records of the sterilization process. THEY MUST BE KEPT FOR 2 YEARS. Some of the autoclaves available on the market are equipped with printers that can generate data about the sterilization process, but this is not necessary anymore. Enbio gives the possibility to store data on a dedicated pendrive, and print them on any printer at a convenient time.

71. STEPS OF WORKING The autoclave works on the principle of moist heat sterilization where steam under pressure is used to sterilize the material present inside the chamber. The high pressure increases the boiling point of water and thus helps achieve a higher temperature for sterilization. Water usually boils at 100°C under normal atmospheric pressure (760 mm of Hg); however, the boiling point of water increases if the pressure is to be increased. Similarly, the high pressure also facilitates the rapid penetration of heat into deeper parts of the material, and moisture present in the steam causes the coagulation of proteins causing an irreversible loss of function and activity of microbes. This principle is employed in an autoclave where the water boils at 121°C at the pressure of 15 psi or 775 mm of Hg.

72. STEPS OF WORKING 6. When this steam comes in contact on the surface, it kills the microbes by giving off latent heat. 7 . The condensed liquid ensures the moist killing of the microbes. 8. Once the sterilization phase is completed (which depends on the level of contamination of material inside), the pressure is released from the inside of the chamber through the whistle. 9. The pressure inside the chamber is then restored back tot eh ambient pressure while the components inside remain hot for some time.

73. PROCEDURE FOR RUNNING AN AUTOCLAVE Before beginning to use the autoclave, it should be checked for any items left from the previous cycle. A sufficient amount of water is then put inside the chamber. Now, the materials to be sterilized are placed inside the chamber. The lid is then closed, and the screws are tightened to ensure an airtight condition, and the electric heater is switched on.

74. PROCESURE 5. The safety valves are adjusted to maintain the required pressure in the chamber. 6. Once the water inside the chamber boils, the air-water mixture is allowed to escape through the discharge tube to let all the air inside to be displaced. The complete displacement can be ensured once the water bubbles cease to come out from the pipe. 7. The drainage pipe is then closed, and the steam inside is allowed to reach the desired levels (15 lbs in most cases). 8. Once the pressure is reached, the whistle blows to remove excess pressure from the chamber.

75. PROCEDURE After the whistle, the autoclave is run for a holding period, which is 15 minutes in most cases. Now, the electric heater is switched off, and the autoclave is allowed to cool until the pressure gauge indicates the pressure inside has lowered down to that of the atmospheric pressure. The discharge pipe is then opened to allow the entry of air from the outside into the autoclave. Finally, the lid is opened, and the sterilized materials are taken out of the chamber.

76. TYPES OF AUTOCLAVE PRESSURE COOKER TYPE AUTOCLAVE GRAVITY DISPLACMENT TYPE AUTOCLAVE POSITIVE PRESSURE DISPLACEMENT TYPE NEGATIVE PRESSURE DISPLACEMENT TYPE

77. PRESSURE COOKER TYPE These, as domestic pressure cookers, are still in use in many parts of the world. The more modern type has a metal chamber with a secure metal lid that can be fastened and sealed with a rubber gasket. It has an air and steam discharge tap, pressure gauge, and safety valve. There is an electric immersion heater in the bottom of the chamber.

78. AUTOCLAVE PRESSURE COOKER

79. GRAVITY DISPLACMENT TYPE This is the common type of autoclave used in laboratories. In this type of autoclave, the steam is created inside the chamber via the heating unit, which then moves around the chamber for sterilization. This type of autoclave is comparatively cheaper than other types.

80. GRAVITY DISPLACEMENT AUTOCLAVE

81. POSITIVE PRESSURE DISPLACEMENT TYPE In this type of autoclave, the steam is generated in a separate steam generator which is then passed into the autoclave. This autoclave is faster as the steam can be generated within seconds. This type of autoclave is an improvement over the gravity displacement type.

82. NEGATIVE PRESSURE DISPLACEMENT TYPE This is another type of autoclave which contains both the steam generator as well as a vacuum generator. Here, the vacuum generator pulls out all the air from inside the autoclave while the steam generator creates steam. The steam is then passed into the autoclave. This is the most recommended type of autoclave as it is very accurate and achieves a high sterility assurance level. This is also the most expensive type of autoclave.

83. NEGATIVE PRESSURE TYPE AUTOCLAVE

84. PRECAUTIONS Although autoclaves are pretty simple to use, there are certain rules of precautions to be followed while operating an autoclave. Some of the important precautions to be followed while running an autoclave are: Autoclaves should not be used to sterilize water-proof or water-resistant substances like oil or powders. The autoclave should not be overcrowded, and the materials should be loaded in a way that ensures sufficient penetration of articles by the steam. TheThe items to be autoclaved should always be placed in a secondary container.

85. PRECAUTIONS Only autoclavable bags are to be used to autoclave packaged waste. To ensure sufficient penetration, articles should be wrapped in something that allows penetration by steam, and materials like aluminum foils should not be used. The items placed inside the chamber should not touch the sides or top of the chamber. The wastes and clean items should be autoclaved separately. Attempts to open the lid when the autoclave is working should never be made. Liquid components should never be autoclaved in sealed containers.

86. PRECAUTIONS The liquid inside the containers should only be filled 2/3rd of the total volume to prevent the spilling of the liquid. Plastic or polyethylene trays or containers should not be used as they might melt and damage the autoclave. Besides, never autoclave flammable, reactive, corrosive, toxic or radioactive materials, household bleach, or paraffin-embedded tissue. The paper should not be placed directly inside an autoclave as it is a combustible substance. It should be autoclaved in a waste bag on a bio bag setting to prevent fire.

87. AUTOCLAVE TEMPRATURE 121° C Autoclave Cycles To be effective, the autoclave must reach and maintain a temperature of 121° C for at least 30 minutes by using saturated steam under at least 15 psi of pressure. Increased cycle time may be necessary depending upon the make-up and volume of the load.

88. AUTOCLAVE PRESSURE approximately 15 pounds per square inch Operating procedures. When used properly, autoclaves are safe and highly effective. Autoclaves use saturated steam under pressure of approximately 15 pounds per square inch to achieve a chamber temperature of at least 250°F (121°C) for a prescribed time—usually 30–60 minutes.

89. PRINCIPLE OF AUTOCLAVE The autoclave works on the principle of moist heat sterilization where steam under pressure is used to sterilize the material present inside the chamber. The high pressure increases the boiling point of water and thus helps achieve a higher temperature for sterilization.

90. CLEANING PROCEDURE OF AUTOCLAVE Caring for your autoclave is very important and can be easily overlooked. We often see this step neglected which can cause high and frequent repair costs. A lack of maintenance will also lead to deterioration and excessive wear of the contents being sterilized. Let's go over a few points to make caring for your autoclave or steam sterilizer easier for you.

91. DAILY CLEANING 1) It is very important that the contents being sterilized are clean and free from debris, blood and organic tissue. Otherwise the instruments or sterilizer may become damaged. We strongly recommend using an ultrasonic cleaner such as the DuraSonic to help with the cleaning process. 2) Inspect the door gasket for excessive wear or cracking. The gasket and mating surface should be cleaned with a mild detergent such as Spray Nine™ or Fantastik™ using a cloth or sponge. 3) When running a sterilization cycle it is very important to not overload the sterilizer trays because it will cause inadequate sterilization and drying. 4) Always be sure to use a Class 5 Chemical Integrator Test Strip with every cycle for immediate reassurance that the correct parameters have been met to achieve sterilization.

92. WEEKLY CLEANING 1) Keeping your autoclave clean is one of the most important points. Be sure to clean the trays and rack with a Non-Scratch Scour Pad using a mild non-abrasive detergent such as Bon Ami™. Always rinse the instrument well and be sure to NOT USE steel wool, wire brush, or bleach. 2) Completely drain the water from the reservoir and replenish with fresh distilled water. 3) It is strongly recommended to perform a biological live spore test weekly or at least monthly to ensure sterilization.

93. MONTHLY CLEANING 1) Clean the chamber and flush lines using the recommended autoclave cleaner following the cleaner’s instructions. Normally you will need 2 gallons of distilled water to complete this job. 2) Inspect the cord and plug for overheating and excessive wear—this could be a fire hazard. If this is the case, the power cord should be replaced. Some power cords are quick disconnect and easily replaced. If not, the replacement will need to be done by a certified repair company.

94. YEARLY CLEANING On a yearly basis you should have your autoclave inspected, cleaned thoroughly, tested and calibrated. This is typically referred to as a PM or Preventative Maintenance Service. This service would normally include the replacement of wear & tear parts such as gaskets, seals and filters. This will ensure your sterilizer is running properly and remaining in good working order. If your autoclave is used very heavily we would recommend this service bi-annually. Our certified technicians at Duraline Systems can perform this preventative maintenance in the shop or on-site depending on your location. Read More about Autoclave Service with Duraline Systems or call toll free 1-877-561-0500 to speak with a certified autoclave technician today. We work with all major brands Tuttnauer, Midmark Ritter, Scican Statim, Pelton and Crane, Cox, CPAC, Sterident, Dentronix and more. Duraline even offers emergency loaners.

95. CLEANING OF AUTOCLAVE