As of early April 2020, the world is stricken by the recent pandemic outbreak  of a new strain of Coronavirus, previously unknown to mankind, denominated Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2). This virus is part of the family of the coronaviruses, which are viruses commonly affecting mammals and birds. Although the respiratory tract infections on humans caused by this family of viruses are usually common colds (Human Coronavirus 229E, Human Coronavirus NL63, Human Coronavirus OC43, and Human Coronavirus HKU1), sometimes they beget viral pneumonia and rarely they can be the cause of a severe acute respiratory syndrome (SARS) (SARS-CoV, MERS-CoV, and SARS-CoV-2) . SARS-CoV-2 causes a disease, better known as COVID-19 (CO for Corona, VI for Virus, D for disease and 19 for the year in which it was identified), with symptoms spanning from mild (e.g., fever, tiredness, dry and continuous cough, and shortness of breath, diarrhoea, and sore throat [3, 4]) to serious (e.g., viral pneumonia and multi-organ failure [5, 6]). SARS-CoV-2, similarly to other viruses , seems to have spilled over to humans from wild animals . As a consequence, the human immune system, having never been in contact with such a virus, lacks the ability to fight against the pathogen , which can have particularly dangerous effects on subjects with already weak immune systems, or immunosuppressed or elderly subjects with existing preconditions. Based on the current information, the virus has been classed as a Hazard Group 3 (HG3) pathogen  and the World Health Organization (WHO) has stated that laboratory tests and practices should follow biosafety level 3 guidelines .
The COVID19 outbreak impact on European countries was twofold. First, the supply chain of personal protective equipment (PPE), medical devices (MDs), consumables and spare parts revealed its frailty in its dependence on China’s capability to produce them, severally hindered by the lockdown since January 2020. Second, this world pandemic has been causing an unprecedented demand of hospitalizations, especially in intensive care units (ICUs), since its early stages. This set off a chain reaction affecting a number of other routine hospitalizations (e.g., elective surgeries), which were postponed giving priority to ICU beds in terms of resources (spaces, personnel, equipment) Moreover, healthcare staff is highly exposed to the risk of catching COVID-19 themselves, due to the inner nature of their daily routine, which exposes them to physical contact with patients. The combination of these factors has created in Europe de facto conditions that are usually typical of ‘low-resource settings’, generating havoc among all the countries, independently from their wealth level.
The combination of a frail supply-chain and an unprecedented demand of ICU beds demonstrated the extent to which countries were not prepared to tackle global disasters, such as the current pandemic.
This is particularly evident in Europe, where many healthcare systems (e.g., France, Italy, Spain and the UK), being rated among the best ones in the world , are being heavily overburdened by the ever-increasing number of patients needing hospitalization or intensive care [12,13,14,15]. The national health systems, in fact, lack essential resourcesFootnote 1 for dealing with COVID-19, including MDs (e.g. surgical masks, ventilators, infusion pumps), PPEs  and healthcare personnel (who is being reduced by the disease itself).
For the first time after decades, the progressive scarcity of devices, equipment and resources has raised also in high-income countries the problem of resource allocation and prioritisation. The latter could expose a part of the population, probably the most disadvantaged individuals, to further difficulties in accessing healthcare services .
The urgent need for equipment directly affects the role of clinical engineers, professionals who are in charge of verifying that all the medical and electro-medical devices are compliant with the essential requirements imposed by the national laws, before authorising their use in hospital settings. In Europe, this means compliance with the European framework of directives and regulations certified by the presence of the CE mark. Strictly following international standards is the regular path chosen by the manufacturers in order to guarantee the compliance of their products to the above-mentioned requirements, in terms of performances and safety. The current situation has highlighted the flaws of the regulations. For instance, the non-universality of regulations, norms and international standards is clearly evident in these situations of emergency. The problem of non-universality of technical norms is well-known in the context of low-resources settings, especially in the context of Low- and Middle-Income Countries (LMICs) as highlighted by the authors of this paper who have been extensively acting to overcome this issue [18, 19]. The COVID19 pandemic, is dramatically demonstrating that this limit is paramount also in high-income countries during emergencies. The international standards, indeed, proved to be often too generic and demanding, resulting difficult to be implemented in many countries, in terms of time, costs and overall effort required, thus jeopardizing a prompt response to emergencies. This is everyday evidence in lower-income countries, and it is becoming now clear also in high-income ones.
In this critical context, we have joined our efforts to write this manuscript in order to share our considerations on the necessity of identifying a set of minimum requirements to test PPEs for use in hospitals during the COVID19 pandemic. We hope this contribution may be relevant for the readers, helping them navigating the variegated context of PPEs regulatory framework. The proposed approach reflects a minimum set of tests that should always be considered despite the waivers issued by several states. This discussion should then be continued, once this crisis will be over, especially with regard to lower-income countries, where the inadequacy of international norms is clear also in everyday conditions.