All matter is made up of atoms consisting of a nucleus surrounded by negatively charged electrons, similar to the sun surrounded by the planets. The nucleus is made up of a zoo of different particles. The most significant are called neutrons, because they do not carry an electrical charge and positively charged protons. Atoms containing the same number of protons have identical chemical properties and are known as elements. Elements with a different number of neutrons are known as isotopes. There are 88 naturally occurring elements some examples of which are oxygen, iron, sulphur, uranium and radium etc.Some atoms have an excess of energy in their nucleus. They get rid of this energy by emitting some form of radiation. The process is called radioactive decay.

Most of these radiations emitted have enough energy to strip off one or more of the electrons orbiting a nucleus. This process is called ionization and, not surprisingly the sort of radiations that can produce it are called ionizing radiations. Ionizing radiation comes in four main forms: alpha particles, beta particles, gamma rays and X-rays. Each one behaves rather differently and can present different sorts of hazards. (X-rays are a particular form of ionizing radiation produced when high-speed electrons are stopped by heavy materials.)

Steritech uses gamma radiation for its sterilising process

Different parts of the body respond differently when exposed to radiation so we have to have a fairly complex way of describing radiation doses and their potential effect.

The unit used is called the Sievert (Sv) and it is based on 1 joule of energy per kilogram of whatever is being irradiated. This unit allows for a series of factors such as how penetrating is the radiation, what part of the body has been irradiated, how much energy has been deposited in the human tissues etc.

The sievert is a big unit and we usually talk in terms of millisieverts (mSv; one-thousandth of a Sievert or even microsieverts one millionth).

We have to think about the effects of exposure to radiation in two ways. What happens after a large radiation exposure and what may happen in the long-term after receiving a smaller dose.

A very large dose of radiation of more than 10 sievert will cause the death of the person irradiated within a few weeks. Smaller doses of 2 or 3 sievert may make the person nauseous but such a dose is not fatal in the short term.

Smaller doses would not have any immediate effect but may lead to cancer in later life. Even though no effects have been observed below about 50mSv in radiation protection, for maximum safety, it is assumed that any radiation exposure carries some small risk. A dose of 1mSv is considered to represent a risk of 1 in 20,000 (0.005%) of producing some form of cancer. (For comparison the 'natural' incidence of cancer in Australia is about 1 in 3 (0.33%) and about 1 in 6 people in this country will die from some form of cancer.)

No. Sterilization plants have been operating for nearly 50 years and their design and safety controls have developed a high degree of sophistication.

They consist of a deep pool of water to store and shield the radiation source when it is not in use. A cell with thick concrete walls shields the source when it is in use. There are two mazes within each cell. One contains a conveyor to move the product to be irradiated into and out of the cell. The other maze is for access by personnel when the source is in the shielded position. There are duplicated interlocks and several radiation monitoring devices to ensure employees cannot enter the irradiation cell when the source is exposed.

The company has to obtain State Government licences to operate the plants and they are inspected regularly by officers of the Radiation Safety Branches.

Steritech has over 45 years experience in operating sterilization plants in both Sydney and Melbourne. During that time there has not been one accident or incident that has lead to a radiation exposure of either Steritech employees or members of the public.

A surprisingly wide range of things. Perhaps the most important from a public safety point of view is the sterilisation of medical supplies including band-aids, syringes, wound dressings, operating theatre kits, etc. Packaging materials of all sorts are sterilised including wine corks. Animal feed is irradiated to ensure that strange bugs are not being introduced. This is particularly important with laboratory animals, which are kept under carefully controlled conditions. New Zealand for instance won't accept horse feed that hasn't been irradiated. Cosmetics are sterilised, as is packaging for pharmaceuticals. Beehives are irradiated to control American Foul Brood Pest a sort of foot and mouth of bees.

The Australian Quarantine and Inspection Service makes considerable use of Steritech's facilities to ensure that suspect items are irradiated and made safe before being used in Australia.

Yes, but nothing as effective. Steam/heat can be used for small items such as hospital gowns and sheets, however some things are severely damaged by heat. The gas ethylene oxide can be used especially for those things such as teflon which are damaged by large radiation doses. The gas is very toxic (it has to be to kill bugs) and requires very careful handling. Electron beam machines produce a form of less penetrating radiation which can have advantages for materials that are not bulky or are in film or sheet form. For most materials penetrating gamma radiation provides the best assurance that effective sterilisation has occurred

EtO is a gas fumigation - diffusion process. It started off as an insecticide in the 1920's and became widely used as a fumigant for agricultural produce. Like many other chemicals, EtO is a by-product of the petroleum refining process. A large part of the output is used in the medical, cosmetic and spice sterilisation but its most common use is in producing other chemicals such as Ethylene Glycol, the main ingredient in automotive antifreeze. It is also used in the production of detergents and cosmetics such as shampoos and soap.

The EtO molecule is made up of two carbon and four hydrogen atoms, joined to one oxygen atom. EtO has a very low boiling point and becomes highly active at room temperature. It vapourises and permeates rapidly through packaging, dissolving in substances such as plastic and rubber. Under normal atmospheric conditions EtO is deadly to all types of micro-organisms

Ethylene Oxide is well placed to deal with a wide range of products. For example, plastics which may not physically cope with other types of processing are well suited to Ethylene Oxide. Being an extremely small gas, EtO will penetrate most forms of packaging. Powders, timber and other solids are easily treatable as the gas will flow around irregular surfaces

There are many factors that the Steritech Sales Executive must take into consideration before giving a quote for treatment. These include:-


Length, width and depth of the goods (Steritech uses centimetres as a rule)

Weight (kg’s)

Dose required (for Irradiation)

Cycle Parameters (for EtO)

Volume being treated (cubic metres)


Speak to your local Sales Executive. Click here to go to contact detail

Your goods would only be ready for despatch once they had been released by Steritech’s QA Department and cost to treat the goods had been paid.

Receiving and Despatch are open Monday – Friday from 8.00am until 3.30pm

Receiving and Despatch are open Monday – Friday from 8.00am until 3.30pm

Steritech’s plants are operational 24 hours a day, 7 days a week.

Steritech currently has 3 plants operational within Australia:


Victoria

160 South Gippsland Highway

Dandenong Vic 3175

P.O. Box 4040

Dandenong South

Vic 3164, Australia



New South Wales

5 Widemere Road

Wetherill Park NSW 2164

P.O. Box 6632

Wetherill Park NSW 2164, Australia




Queensland


180-186 Potassium Street

Narangba QLD 4504

P.O. Box 376

Burpengary QLD 4505, Australia




Further contact details can be found on the Contact Us page