Autoclave
A modern front-loading autoclave
Uses	Sterilization
Inventor	Charles Chamberland
Related items	Waste autoclave
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An autoclave is a pressurized device designed to heat aqueous solutions above their boiling point to achieve sterilization. Sterilization (or sterilisation, see spelling differences) refers to any process that effectively kills or eliminates transmissible agents (such as Fungi Charles Chamberland ( March 12, 1851 - May 2, 1908) was a French Microbiologist from Chilly-le-Vignoble in the department of Jura A waste autoclave is a form of solid waste treatment that utilises Heat, Steam and Pressure of an industrial Autoclave in the processing A pressure vessel is a closed container designed to hold gases or liquids at a Pressure different from the ambient Pressure. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid Sterilization (or sterilisation, see spelling differences) refers to any process that effectively kills or eliminates transmissible agents (such as Fungi It was invented by Charles Chamberland in 1879. Charles Chamberland ( March 12, 1851 - May 2, 1908) was a French Microbiologist from Chilly-le-Vignoble in the department of Jura Year 1879 ( MDCCCLXXIX) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a Common ^[1] The term autoclave is also used to describe an industrial machine in which elevated temperature and pressure are used in processing materials.

Introduction

Under ordinary circumstances (at standard pressure), liquid water cannot be heated above approximately 100 °C (99. In Physical sciences standard conditions for temperature and pressure are Standard sets of conditions for experimental measurements to allow comparisons to be made Water is a common Chemical substance that is essential for the survival of all known forms of Life. 99 °C at 101. 325 kPa, 99. 62 °C at 100 kPa) in an open vessel except for special situations. Superheated steam is Steam at a temperature higher than its Saturation temperature. Further heating results in boiling, but does not raise the temperature of the liquid water. Boiling (also called ebullition) a type of Phase transition, is the rapid vaporization of a Liquid, which typically occurs when a liquid However, when water is heated in a sealed vessel such as an autoclave, it is possible to heat liquid water to a much higher temperature. As the container is heated the pressure rises due to the constant volume of the container (see the ideal gas law). Pressure (symbol 'p' is the force per unit Area applied to an object in a direction perpendicular to the surface The volume of any solid plasma vacuum or theoretical object is how much three- Dimensional space it occupies often quantified numerically The ideal gas law is the Equation of state of a hypothetical Ideal gas, first stated by Benoît Paul Émile Clapeyron in 1834 The boiling point of the water is raised because the amount of energy needed to form steam against the higher pressure is increased. In Physics and other Sciences energy (from the Greek grc ἐνέργεια - Energeia, "activity operation" from grc ἐνεργός Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work.

Air removal

When the goal of autoclaving is to achieve sterility, it is very important to ensure that all of the trapped air is removed. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five The reason for this is that hot air is very poor at achieving sterility. Steam at 134 °C can achieve in 3 minutes the same sterility that hot air at 160 °C takes two hours to achieve. Autoclaves may achieve air removal by various means including:

Downward displacement (or gravity type) - As steam enters the chamber, it fills the upper areas as it is less dense than air. This compresses the air to the bottom, forcing it out through a drain. Often a temperature sensing device is placed in the drain. Only when air evacuation is complete should discharge stop. Flow is usually controlled through the use of a steam trap or a solenoid valve, but bleed holes are sometimes used, often in conjunction with a solenoid valve. 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 - Some autoclaves remove air by using a series of steam pulses, in which the chamber is alternately pressurised and then depressurised to near atmospheric pressure.

Vacuum pumps - Some autoclaves use vacuum pumps to suck air or air/steam mixtures from the chamber.

Superatmospheric - This type of cycle uses a vacuum pump. It starts with a vacuum followed by a steam pulse and then a vacuum followed by a steam pulse. The number of pulses depends on the particular autoclave and cycle chosen.

Subatmospheric - Similar to superatmospheric cycles, but chamber pressure never exceeds atmospheric until they pressurize up to the sterilizing temperature.

Uses

Autoclaves are widely used in microbiology, medicine, sterilising instruments for body piercing, veterinary science, dentistry, podiatry and metallurgy. Microbiology (from Greek grc μῑκρος mīkros, "small" grc βίος bios, " Life " and grc -λογία Medicine is the art and science of healing It encompasses a range of Health care practices evolved to maintain and restore Human Health by the Body piercing is the practice of puncturing or cutting a part of the Human body, creating an opening in which jewelry may be worn Veterinary medicine the application of medical, diagnostic, and therapeutic principles to companion, domestic, exotic, wildlife Dentistry' is the "evaluation diagnosis prevention and/or treatment (nonsurgical surgical or related procedures of diseases disorders and/or conditions of the oral cavity Podiatry or podiatric medicine is a field of Healthcare devoted to the study and treatment of disorders of the Foot, Ankle, and the "anatomical Metallurgy is a domain of Materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their The large carbon-fiber composite parts for the Boeing 787, such as wing and fuselage parts, are cured in large autoclaves. Composite materials (or composites for short are engineered Materials made from two or more constituent materials with significantly different physical or chemical The Boeing Company is a major Aerospace and defense corporation originally founded by William E WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout WING "ESPN 1410" is a commercial AM radio station in Dayton Ohio operating with 5000 watts at 1410 kHz with studios offices and transmitter located on David The fuselage (from the French fuselé "spindle-shaped" is an Aircraft 's main body section that holds crew and passengers or Cargo ^[2]

Autoclaves in medicine

Stovetop autoclaves - the simplest of autoclaves

A medical autoclave is a device that uses steam to sterilize equipment and other objects. Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work. Sterilization (or sterilisation, see spelling differences) refers to any process that effectively kills or eliminates transmissible agents (such as Fungi This means that all bacteria, viruses, fungi, and spores are inactivated. The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have A virus (from the Latin virus meaning Toxin or Poison) is a sub-microscopic infectious agent that is unable A fungus (ˈfʌŋgəs is a eukaryotic Organism that is a member of the kingdom Fungi (ˈfʌndʒaɪ In Biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions However, prions, like those associated with Creutzfeldt-Jakob disease, also may not be destroyed by autoclaving at the typical 121 degrees Celsius for 15 minutes or 134 degrees Celsius for 3 minutes, but can be destroyed with a longer sterilisation cycle of 134 degrees Celsius for 18 minutes. A prion (ˈpriːɒn is thought to be an infectious agent that according to current scientific consensus is comprised entirely of a propagated, mis-folded Creutzfeldt-Jakob disease ( CJD) is a very rare and incurable degenerative neurological disorder ( Brain Disease) that is ultimately

Autoclaves are found in many medical settings and other places that need to ensure sterility of an object. Many procedures today use single-use items rather than sterilized, 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 items rather than reusable. A hypodermic needle is a hollow needle commonly used with a Syringe to inject substances into the body A surgical instrument is a specially designed tool or device for performing specific actions of carrying out desired effects during a Surgery or operation such as modifying Forceps are a handheld hinged instrument used for grasping and holding objects A hypodermic needle is a hollow needle commonly used with a Syringe to inject substances into the body A scalpel is a small but extremely sharp knife used for Surgery, anatomical Dissection, and various Arts and crafts. See waste autoclave. A waste autoclave is a form of solid waste treatment that utilises Heat, Steam and Pressure of an industrial Autoclave in the processing

Because damp heat is used, heat-labile products (such as some plastics) cannot be sterilised this way or they will melt. Humidity is the amount of water vapor in the air In daily language the term "humidity" is normally taken to mean Relative humidity. Lability refers to something that is constantly undergoing change or something that is likely to undergo change Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products Some paper or other products that may be damaged by the steam must also be sterilized another way. Paper is thin material mainly used for writing upon printing upon or packaging Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work. 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 grown as an alternative to incineration due to environmental and health concerns raised by combustion byproducts from incinerators, especially from the small units which were commonly operated at individual hospitals. Incineration is a waste treatment technology that involves the Combustion of organic materials and/or substances Incineration or a similar thermal oxidation process is still generally mandated for pathological waste and other very toxic and/or infectious medical wastes.

Chemiclave

Unlike the humid environment produced by conventional steam, the unsaturated chemical vapor method is a low-humidity process. Humidity is the amount of water vapor in the air In daily language the term "humidity" is normally taken to mean Relative humidity. Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work. In Chemistry, saturation has five different meanings In Physical chemistry, saturation is the point at which a Solution of a substance A chemical substance is a Material with a definite chemical composition. A vapor or vapour (see Spelling differences) is a substance in the Gas phase at a Temperature lower than its Critical temperature No time-consuming drying phase is needed, because nothing gets wet. The heat-up time is shorter than for most steam sterilizers, and the heaters stay on between cycles to minimize warm-up time and increase the instrument turnover. Sterilization (or sterilisation, see spelling differences) refers to any process that effectively kills or eliminates transmissible agents (such as Fungi

Autoclave quality assurance

Multiple large autoclaves are used for processing substantial quantities of laboratory equipment prior to reuse, and infectious material prior to disposal. The machine in the middle is a washing machine, the machine to the right is the Autoclave

Sterilization bags often have a “sterilization indicator mark” that typically darkens when sterilization temperatures have been reached. Comparing the mark on an unprocessed bag to a bag that has been properly cycled will show an obvious visual difference.

There are physical, chemical, and biological indicators that can be used to ensure an autoclave reaches the correct temperature for the correct amount of time. Physics (Greek Physis - φύσις in everyday terms is the Science of Matter and its motion. Chemistry (from Egyptian kēme (chem meaning "earth") is the Science concerned with the composition structure and properties Foundations of modern biology There are five unifying principles A pH indicator is a halochromic chemical compound that is added in small amounts to a Solution so that the PH ( Acidity or Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature For other uses see Time (disambiguation Time is a component of a measuring system used to sequence events to compare the durations of

Chemical indicators can be found on medical packaging and autoclave tape, and these change color once the correct conditions have been met. A chemical substance is a Material with a definite chemical composition. Medicine is the art and science of healing It encompasses a range of Health care practices evolved to maintain and restore Human Health by the Packaging is the science art and technology of enclosing or protecting products for distribution storage sale and use Autoclave tape is an Adhesive tape used in Autoclaving to indicate whether the correct temperature has been reached for the elimination of all living organisms This color change indicates that the object inside the package, or under the tape, has been autoclaved sufficiently. Biological indicators include attest devices. These contain spores of a heat-resistant bacterium, Geobacillus stearothermophilus. In Biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions Bacillus stearothermophilus (or Geobacillus stearothermophilus) is a rod-shaped Gram-positive Bacterium and a member of the division If the autoclave does not reach the right temperature, the spores will germinate, and their metabolism will change the color of a pH-sensitive chemical. Germination is the process whereby growth emerges from a period of dormancy Metabolism is the set of Chemical reactions that occur in living Organisms in order to maintain Life. pH is the measure of the acidity or alkalinity of a Solution. Physical indicators often consist of an alloy designed to melt only after being subjected to 121°C or 249°F for 15 minutes. An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has If the alloy melts, the change will be visible.

In addition to these indicators, autoclaves have timers, temperature and pressure gauges that can be viewed from the outside. Many techniques have been developed for the measurement of Pressure and Vacuum.

There are certain plastics that can withstand repeated temperature cycling greater than the 121°C or 249°F required for the autoclaving process. Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products PFA and PP (#5) are examples.

Some computer-controlled autoclaves use an F₀ (F-naught) value to control the sterilization cycle. Sterilization (or sterilisation, see spelling differences) refers to any process that effectively kills or eliminates transmissible agents (such as Fungi F₀ values are set as the number of minutes of equivalent sterilization at 121°C or 249°F (e. g: F₀ = 15 min. ). Since exact temperature control is difficult, the temperature is monitored, and the sterilization time adjusted accordingly.

See also

• Aerated autoclaved concrete
• Pressure cooker
• Sterilization (microbiology)
• Waste autoclave

References

External links

• Strain 121