Covid-19 Testing Self -Test Kit , Sterilising using Ethylene Oxide
Approx 1 min. 40 sec. video
Summary updated December 2018.)
The major use of ethylene oxide is as a chemical intermediate in the manufacture of ethylene glycol. Ethylene oxide is also used as a sterilizing agent for medical equipment and a fumigating agent for spices. The acute (short-term) effects of ethylene oxide in humans consist mainly of central nervous system depression and irritation of the eyes and mucous membranes. Chronic (long-term) exposure to ethylene oxide in humans can cause irritation of the eyes, skin, nose, throat, and lungs, and damage to the brain and nervous system. There also is some evidence linking ethylene oxide exposure to reproductive effects. EPA has concluded that ethylene oxide is carcinogenic to humans by the inhalation route of exposure. Evidence in humans indicates that exposure to ethylene oxide increases the risk of lymphoid cancer and, for females, breast cancer.
'Dermal or ocular contact with solutions of ethylene oxide has caused irritation of the skin and eyes in humans.'
Guidance COVID-19: guidance on alternative swab types and transport media. , Updated 16 July 2020
Difficulties with supply chain for key virological testing components such as swabs and transport medium have led to local variations in practice with respect to sampling which may also impact on PCR diagnostic test performance.
What You Should Know About Medical Swab Sterilization
(https://blog.puritanmedproducts.com/what-you-should-know-about-medical-swab-sterilization- Dec 21 , 2015)
'Sterilization is an incredibly important part of any medical process—everybody knows that. But how medical tools are sterilized is much less common knowledge.
The Most Commonly Used Methods for Sterilizing Medical Equipment Are...
- ETO (ethylene oxide gas)
- Gamma irradiation
While there are other methods of sterilization—heat, dry heat, chemical, UV and others—these are the methods most commonly used on medical devices.
Autoclaves work, well, basically they work like pressure cookers. They blast medical devices with hot steam that kills germs and microbes. The added pressure inside the autoclave means that the water boils at a higher temperature, so the steam is a whopping 121-140° Celsius—hot enough to sterilize surgical instruments and other reusable medical equipment.
Ethylene oxide sterilization is used for more delicate instruments and devices that can't tolerate heat or moisture. The medical devices are treated with ethylene oxide gas, which disrupts the DNA of any microorganisms living on them and stops the organisms from reproducing.
Gamma rays are a form of electromagnetic radiation—like x-rays, but with higher energy. The rays pass through plastics and kill bacteria by breaking the covalent bonds of bacterial DNA. Gamma radiation is very penetrating, and is commonly used for sterilization of disposable medical equipment, such as syringes, needles, and IV sets.
OVERVIEW OF STERILIZATION TECHNOLOGY COMPARISON
Overview of products commonly treated with gamma irradiation
EO STERILIZATION VERSUS GAMMA STERILIZATION
(https://int-enviroguard.com/blog/eo-vs-gamma/ - Apr 6, 2019)
Sterilization is the removal of all life forms and agents from the surface of a material or from a fluid/compound.
Examples of such agents include:
EO Sterilization- Cons - Ethylene oxide may be harmful to people.
Gamma Vs Ethylene Oxide (EtO) Sterilisation
Let’s first take a look at gamma sterilisation and when it is used. This type of sterilisation is an irradiation process where the product is exposed to gamma rays. This type of method is efficient, effective and relatively simple. It is a common sterilisation process as it is predictable and is able to repeat time and time again with accuracy.
Ethylene Oxide (EtO or EO) Sterilisation
The other common sterilisation method is EtO sterilisation which is used for products that are sensitive to radiation. EtO is a type of gas and the process involves exposing the products to the gas at a specified temperature, relative humidity, and pressure for a controlled amount of time in order to ensure proper sterilisation has taken place.
As EtO is a toxic gas which is highly explosive, organisations must comply with strict usage guidelines.
Sterile Swabs for DNA Collection -The Importance of Choosing the Right One
Foam Sterile Swabs
The foam is highly absorbent, which is ideal for collecting and retaining saliva. Since they’re non-abrasive, they won’t cause any discomfort to the DNA donor.
Their gentle tip also makes it easy for nurses and medical professionals to rub the swab thoroughly in the cheek pocket and near the gum line, where saliva often accumulates.
Among all the types of sterile swabs, foam tip swabs have the highest particle collection capacity.
Flocked Sterile Swabs
Like foam tip swabs, flocked sterile swabs have superior collection and release characteristics. Although they aren’t as absorbent as the foam tip swabs.
Polyester flock swabs are commonly used in buccal cell collection, and due to their excellent absorption and elution capabilities, they are the go-to options for rapid diagnostic testing.
Cotton Sterlile Swabs
By nature, cotton is a bit more abrasive than the foam and flocked swabs described above. Yet, that can be an advantage for DNA collection – it provides ample friction for releasing buccal cells. It’s also still gentle enough to prevent any discomfort.
Cotton sterile swabs are also versatile because you can either elute the swab in a buffer or remove the tip and drop it into a vial. Like the varieties described above, cotton sterile swabs are available in a variety of sizes and quantities, and are packaged individually.
Choosing the Right Sterile Swab
Now that you’re familiar with the different swab options available for DNA collection, which will you choose? Here are some factors to consider before making your decision:
- Do you need an ample DNA size for your application, or will it suffice to have a small sample?
- How old are the donors from whom you’re collecting DNA?
- Will a professional be collecting the DNA, or will the donor themselves be performing the retrieval?
- Is the sterile swab going to be part of a kit?
- Will the samples be transported, or will the tests be performed on premises?
'The acute (short-term) effects of ethylene oxide in humans consist mainly of central nervous system depression and irritation of the eyes and mucous membranes. Chronic (long-term) exposure to ethylene oxide in humans can cause irritation of the eyes, skin, nose, throat, and lungs, and damage to the brain and nervous system.'
'Dermal or ocular contact with solutions of ethylene oxide has caused irritation of the skin and eyes in humans.'( See - Ethylene Oxide health hazard information ).
Covid-19 Testing Self -Test Kit uses Ethylene Oxide to sterlise the swabs.
Considering the delicate nature of the oral and nasopharyngeal mucosa and the proximity of important anatomical structures there is an urgent need for health and safety assessment of the oral medical tests and swabs especially their use in covid -19 testing as asymptomatic people are coerced into frequent , invasive , unnecessary and unjustified diagnostic testing.
( photo from-https://www.nhs.uk/conditions/nasopharyngeal-cancer/)