FOI release

Freedom of Information request on COVID-19 Lateral Flow Tests and ethylene oxide (FOI 22/051)

Published 31 May 2022

FOI 22/051

7th February 2022

Dear,

Thank you for your information request, dated 11 January where you asked for “Please can you advise what the safe limit is for a human to be in contact with ethylene oxide on the lft swabs for COVID

Please can you advise what the toxic dose of ethylene oxide would be on the lateral flow tests for COVID.

How many swabs would you have to take to exceed the safe limit.

What long term studies have been done on the lft tests and their impact on human health.

How accurate are lft tests.

What unbiased and peer review evidence is there to prove taking a lft has had a reduction on transmission.

What long term studies have been conducted to prove they are safe over what period of time.

Is there any chance there could be lung damage similar to that of asbestosis following continued use of lft tests.

If so what is the risk?

Is there a risk of cancer from using the lft test.

Is there a chance you could damage the blood brain barrier.

If so what would the risks be?

If as a result damage to my body had occurred from these tests what proof is required  and who is liable.”

We are pleased to provide you the following information.

With regards to your questions related to the ethylene oxide, we would like to reassure you  that the MHRA is aware of concerns about the safety of using ethylene oxide (EO) to sterilise the swabs used in coronavirus testing kits (including lateral flow tests).

Ethylene oxide is a gas that is commonly used to sterilise many different types of medical devices, including swabs used in test kits.

The sterilisation process consists of a number of highly controlled and monitored stages, including removing ethylene oxide after treating the swabs. The amount of residual EO that is allowed has been set (by the international standard ISO 10993-7:2008) according to contact time of the medical device with the person. Contact time is divided into 3 categories: limited, prolonged, and permanent duration.

The swabs used in lateral flow test kits fall under the category of limited contact time. These limits are not further divided by body weight and therefore the limits set are also applicable for children.

These allowable limits were selected to ensure that any residual levels present on the medical device after sterilisation pose minimal risk.

The average time of contact for a single test (around 20 seconds) and the current testing regime (twice a week), means that each person is exposed to any residue on the swab for around 40 seconds per week. Calculating from the allowed residues, a person would need to be tested twice a week for over 40 years for the total contact time to be in a higher contact category. Therefore, the manufacturer’s original calculations that these swabs are in the ‘limited’ contact category are still valid for the current testing regime.

The manufacturer’s original calculations also remain valid for more intensive testing regimes required for some workplaces. Even with daily testing, the risk is still considered to be very low. This is because a person would need to be tested five times per week for over 17 years for the total contact time to be in a higher contact category.

Furthermore, due to the chemical nature of ethylene oxide, any residual amount left on the swab is likely to evaporate off once the packaging is opened.

In the highly unlikely event that a swab does contain a residual amount above the allowable limit, the risk to the user is still considered to be very low.

As part of the sterilisation process the manufacturer must confirm, and document, that the residual EO level on a medical device is below the specified allowable limit before the device is packaged ready for use. The whole process is overseen by an independent third-party organisations before a CE/CE UKNI/UKCA mark can be placed on the medical device. The identifying number of the third party can be found next to the CE/UKCA mark symbol on the packaging of the swab.

What long term studies have been done on the lft tests and their impact on human health.

Lateral Flow Devices are a type of testing device, there are many different LFDs on the market for COVID, manufactured by different companies.  DHSC have published lateral flow performance data concerning the devices they manufacturer and use, which can be found at Lateral flow device performance data - GOV.UK (www.gov.uk) .

How accurate are lft tests.

As above, the DHSC have published lateral flow performance data concerning the devices they manufacturer and use, which can be found at Lateral flow device performance data - GOV.UK (www.gov.uk).  Furthermore, there are several rolling systematic reviews ongoing at the moment, please see https://pubmed.ncbi.nlm.nih.gov/34383750/ and https://pubmed.ncbi.nlm.nih.gov/33760236/

What unbiased and peer review evidence is there to prove taking a lft has had a reduction on transmission.

The MHRA are aware of the following peer reviewed publications in this field:

• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8136027/
• https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)01908-5/fulltext

We also suggest that you consult the Scientific Advisory Group for Emergencies (SAGE) website (https://www.gov.uk/government/organisations/scientific-advisory-group-for-emergencies), which includes information supporting the governments’ decision making on the Covid-19 pandemic, including information on the isolation of the Covid-19 virus.

What long term studies have been conducted to prove they are safe over what period of time.

See our  response - DHSC have published lateral flow performance data which can be found at Lateral flow device performance data - GOV.UK (www.gov.uk)

If as a result damage to my body had occurred from these tests what proof is required  and who is liable.

Anyone who experiences any adverse event while using a COVID-19 testing product (test or sample collection kit) should report via the Coronavirus Yellow Card website .We strongly recommend you speak with your General Practitioner  ,If you  have concerns about your health while using the lateral Flow test .

Further information on covid-19 tests and tests kits which may be helpful can be found at: For patients, the public and professional users: a guide to COVID-19 tests and testing kits - GOV.UK (www.gov.uk

We hope you find the information useful .

If you have any queries, please reply to this email.

If you disagree with how we have interpreted the Freedom of Information Act 2000 in answering your request, you can ask for an internal review. Please reply to this email, within two months of this reply, specifying that you would like an Internal Review to be carried out.

Please remember to quote the reference number above in any future communications.

If you were to remain dissatisfied with the outcome of the internal review, you would have the right to apply directly to the Information Commissioner for a decision. Please bear in mind that the Information Commissioner will not normally review our handling of your request unless you have first contacted us to conduct an internal review. The Information Commissioner can be contacted at:

Information Commissioner’s Office
Wycliffe House
Water Lane
Wilmslow
Cheshire
SK9 5AF

Yours sincerely

MHRA Customer Experience Centre