The 3D-printable face shield is a reaction to the urgent demand for the protective equipment required by doctors and other professionals due to the spread of the Coronavirus (COVID-19). The shield is developed and consulted with the Czech Ministry of Health. All tests were performed by leading Czech laboratories and hospitals to ensure conclusive and reliable results.
PRUSA PRO Face Shield
More details about the PRUSA PRO Face Shield including the assembly manuals can be found here prusa3d.com/covid19
Before you start cleaning the shield, it is important to protect yourself. Use gloves, a facemask and if possible another face shield. For safety reasons, consider the shield you are about to clean contaminated at every possible surface and take appropriate measures!
In case the shield was contaminated directly by aerosol (e.g. cough) and you have another face shield(s) at your disposal, consider throwing this one into hazardous waste. If this is your only face shield, wash it thoroughly under running water first and make sure you have properly disinfected the sink, otherwise consider it contaminated and alert your colleagues.
Prepare your workplace, where you will clean the shield(s). Disinfect the surface of the desk properly before you start.
Don't clean multiple shields at once, separate them into several batches, avoid cross-contamination!
To ensure the shield is cleaned properly, we recommend disassembling it first:
You can use the Protected: How to assemble the PRUSA PRO face shield to learn more.
It is highly recommended to submerge (sink) the shield parts into disinfection solutions, this way you will ensure that the solution reaches 100 % of the surface. You can also use aerosol (spray) but apply the procedure at least twice to reach most of the surface.
Select one of the disinfecting methods from the table below, let the solution do its job. Most of the solutions will evaporate after several minutes. You can remove the remains using a paper towel, avoid using the same towel on multiple shields, avoid cross-contamination. Always wipe in one direction.
The methods listed below, seem to be the most promising to kill the virus and are currently being verified by the professionals. Hospitals and other medical workplaces can use their professional sterilizing equipment to properly sterilize (disinfect) the face shields before using them again. A test on a single shield is recommended to verify possible damage of the sterilization.
All tests were performed by leading Czech laboratories and hospitals to ensure conclusive and reliable results. Detailed info about the testing facility and conditions of the test are described between the tables.
The tests were conducted on the Prusa Face Shields printed from Prusament PETG Orange. The official design of the Face Shield is available at PrusaPrinters. We cannot guarantee the methods will work on a different design (geometry) or material due to different properties (e.g. PLA will melt if exposed to high temperatures).
|METHOD||CONDITIONS||EFFECTIVE AGAINST||VERIFICATION STATUS|
|Hot Air Dryer||65 °C (149 °F), 60 mins||bacteria, viruses||Verified by SYNLAB1|
|WHO Handrub disinfection*||75% IPA, 5 mins||bacteria, viruses||Verified by UCT2|
|Isopropanol (IPA)||96%, 5 mins||bacteria, viruses||Verified by UCT2|
|Isopropanol (IPA)||75%, 5 mins||bacteria, viruses||Verified by Labtech3|
|Sodium Hypochlorite (household bleach)||min. 0.01 % of hypochlorite (e.g. SAVO 1:10), 2 mins+||bacteria, viruses||Verified by Labtech3, SYNLAB1|
|UV-C||radiation, 30W, wavelength below 280 nm, 15 mins||bacteria, viruses||Verified by SYNLAB1|
|Ethanol||70-80% max**, 5 mins||bacteria, viruses||Verified by UCT2, Labtech3|
|Hydrogen Peroxide||25%, 5 mins||bacteria, viruses||Verified by ZUUSTI5|
*Tested on the WHO Handrub formulation 2
**Higher Ethanol concentration significantly decreases its effectivity
Czech based laboratory, a part of the international SYNLAB group. All the tests included:
One of the country's largest educational and research institutions focused on the chemical industry. All the tests included:
Accredited laboratory with almost 30 years of experience, also a producer of the testing equipment. All the tests included:
A national organization funded by the Ministry of Health, responsible for disease prevention and monitoring. All the tests included:
A public health organization coordinating its activities with the Ministry of Health, part of the system responsible for protecting public health. All the tests included:
The tests in the labs brought fairly good results for the combination of soap and warm water, but the ingredients in the soap may vary across the world. It is, however, highly advised to use the "recommended methods" instead (see the first table), as those methods have been properly verified. However, if no other disinfectant solution is around:
The methods listed below were tested and evaluated as not ideal for the disinfection process or causing structural damage to the shield.
|NOT RECOMMENDED METHODS|
|Autoclave (hot)||High temp. 120 °C+, pressure 200 kPa+||PETG material limit => shield deformation|
|Autoclave (cold)||60 °C, 60 mins||shield deformation (by SYNLAB1)|
|Ethylene oxide||ethylene oxide steam, elevated temp.||time-consuming, several hours|
|Steam sterilizer||80 °C, 60 mins||shield deformation (by UCT2, NIPH4)|
|Ethanol||81-100%||significantly decreased sterilizing effectivity|
|Hydrogen Peroxide Gas Plasma||58%, temp. max 55 °C||not recommended for porous materials, small chamber (e.g. Sterrad NX)|
This section is dedicated to disinfection solutions, which can be bought in the Czech stores or pharmacies. A similar product might be available at your local store. Each product has a link to the producer or reseller. The tests were performed in the Prachatice hospital (Czechia).
The tests included:
Note: these products might leave stains, use a wet towel afterward to clean the visor
|PRODUCT NAME||SMEAR TEST RESULT||LINK|
|Incidin Foam||Entire shield negative (no virus)||cs-cz.ecolab.com|
|Sekusept Plus||Entire shield negative (no virus)||cs-cz.ecolab.com|
|Desprej Sensitive||Entire shield negative (no virus)||www.schuelke.com/cz-cs|
|Eso Deterferri||Entire shield negative (no virus)||www.itravnik.cz|
|4Gel antibakterial||Entire shield negative (no virus)||www.4clean.cz|
|Anti-Covid dezinfekce||Entire shield negative (no virus)||www.auto-jamar.cz|
|Imagin||Entire shield negative (no virus)||www.myciprostredky.cz|
|ProFloor Mach||Entire shield negative (no virus)||www.profarm.cz|
|Skinsept F||Printed parts positive, visor negative||cs-cz.ecolab.com|
|Septoderm||Printed parts positive, visor negative||www.schuelke.com|