GasDocUnit® FAQ

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Initiative Transparent Animal Testing

Which standards does the GasDocUnit® comply with?

CE-Conformity, AVMA Guidelines 2020, German Animal Welfare Act (TierSchG), Ordinance on the Protection of Laboratory Animals (TierSchVersV) and Directive 2010/63/EU

Why a new euthanasia solution – Is there a need compared to the existing systems?

YES: There is a need for a euthanasia solution that is humane.

And in order to fully support the quality management of research institutions, the GasDocUnit® is fully automated, user‐independent and tamper proof, with no knobs, screens or other controls that allow for manual changes by the users.

And in terms of employee leadership assistance, the employees feel more comfortable using such device because it takes away the burden of a correct execution. Therefore, alternatives to the GasDocUnit® should always be examined:

❤:  If they are developed and tested by a scientific institution

❤:  If they allow for euthanasia in the home cage/IVC

❤:  If the IVC lid needs to be lifted or even replaced by a new lid

❤:  If the operator can really see every cage/IVC within the euthanasia “chamber”

❤:  If they need flow meters, flow restrictors or further additional devices which are error-prone

❤:  If they can guarantee for a homogeneous distribution of CO2

❤:  If they allow for manual adjustments to the settings (for example the flow‐rate) which create the risk of misuse and human error

❤:  If they can be operated anywhere within the lab or if they need to be operated under a hood

❤:  If they need active scavenging or even active disposal of the CO2

❤:  If they really need heated components to prevent “Tank Freeze Ups”, given that freezing starts at a usage of 20 L/min.

❤:  If they really guarantee for a minimum time spent, since the overall consumed time of any euthanasia process is as well determined by the testing for occurred death and documentation after the euthanasia itself

Is a centralized euthanasia process with large chambers claiming to have “a higher throughput” better?

NO: Centralized euthanasia with large chambers, claiming to have “a higher throughput”:

 may be problematic for the animals:

  • if the CO2 is not distributed gradientless
  • in terms of the possibility to observe every cage/IVC within large chambers (conformity with the laws and guidelines?)

❤  it takes its toll on the employees (imagine killing > 200 mice in a row before going into the weekend… emotional consequences?)

 is more expensive because:

  • the cages/IVCs need to be brought to that central location and there the animals are cared for each day until “D‐day” (3 mice IVC ≈ 6 EUR/day)
  • more cages/IVCs are needed in total
  • the large chambers themselves are more expensive
  • the large chambers consume more CO2
  • if these large chambers have a breakdown, servicing and repairing is more expensive
  • if guidelines change, the large chambers need to be serviced which most likely has an impact on the institutions processes

What are the newest developments within the GasDocUnit® ?

The newest version has a variable CO2 inlet pressure range of 1 to 10 bar (dyn.). It no longer requires external filters and it has an intelligent CO2+air control as well as an automatic “purge mode” that removes residual CO2 from the unit.

How is the GasDocUnit® tested & by whom?

We are developing and continuously advancing the GasDocUnit® together with the Cologne Cluster of Excellence – “CECAD” at the University of Cologne. This means that all tests are performed by independent bodies, independent researchers, independent veterinarians and independent animal technicians.

What about hygienic matters with the GasDocUnit®?

In the initial development, the CECAD conducted hygiene tests (wipe tests) with the GasDocUnit® for more than two years. It is hygienically safe and even maintenance-free. The operators can leave the entire enrichment in the IVC during its operation. The GasDocUnit® can be surface cleaned with water or non-abrasive and solvent free cleaning agents and can be disinfected with Bacillol 30 Foam® or Dismozon pur® . The GasDocUnit® is not dishwasher safe and not autoclavable.

Where is it allowed to use the GasDocUnit®?

Generally, this is to decide by each institution and by the officer for safety and health protection. Assisting this decision, we can state that all IVCs have leaks and small amounts of CO2 will leak from the IVC during the operation of the GasDocUnit®. However, the GasDocUnit® will always remain below the values defined as maximum levels by: the “IFA Report 1/2021 List of Hazardous Substances 2021 Hazardous Substances in the Workplace” and the “COMMISSION DIRECTIVE 2006/15/EC of 7 February 2006” establishing a second list of indicative occupational exposure limit values in implementation of “Council Directive 98/24/EC” and amending “Directives 91/322/EEC and 2000/39/EC”. The Maximum Occupational Concentration (“MAK” value) of CO2 of 9000 mg/m3 is not exceeded. Such small quantities of CO2 are used that it may be operated everywhere within the laboratory. Therefore, we may say that the product can be safely used anywhere in the laboratory without the need to operate it under a hood. And the GasDocUnit® does not need an extraction system (“active scavenging”) for the CO2.


Maintenance, upgrades/updates and changes in laws and guidelines

Generally, the GasDocUnit®   is maintenance free. Of course, we can also offer our customers a maintenance plan, if e. g. their quality management requires this. The customers then would send us his units (in bulk or successively – for non-interrupting the customers processes) and we would do the check-up and maintenance. Besides we can offer to sell maintenance tools (or tell the customer which ones to buy) so that customers even can do the maintenance by themselves. Of course, our customers can ask for upgrades/updates at any time and we will be happy to assist. Changes in laws and guidelines will be adopted by us for new versions of the GasDocUnit®  and can also be acquired by existing customers through upgrades/updates. For example, the changes of the AVMA guidelines 2013 to 2020: many of our customers sent us their older units successively for upgrading them to comply with the AVMA guidelines 2020. Besides this upgrade we updated all units with all of the newest features whenever possible (and without extra costs for the customers). Ecology is very important to us, which is why we offer it this way, even if the economy “suffers” from it.

Why not one single GasDocUnit® for all different IVCs? 

During the development and testing phase of the GasDocUnit®, feedback and results clearly denied a “one for all” solution. To the contrary, a solution that is:

  humane, focusing on a truly gradientless distribution of the CO2-O2 mixture,

  as simple as possible and

  which is able to avoid any misuse and human error,

became one of the main targets. Secondly: Our experience and the experience of researchers within different institutions showed that adaptors always are missing, when they are needed the most.

Why is the operator of a GasDocUnit® able to interrupt the euthanasia at any stage?

The IVCs can be undocked at any time from the GasDocUnit®. Depending on when the cycle is interrupted, the animals may not be euthanized and the operator has to take appropriate, humane measures. The option of stopping the cycle at any time was specifically requested by veterinarians. A necessary intervention must always be possible for the operators, in case of an acute condition of the animals. In addition, the operators must remain independent and responsible in their obligation of a proper euthanasia. Besides, in our opinion systems which do not allow the operator to stop the process at any time will cause problems with the risk assessment (as an integral part of the CE/conformity declaration).

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