| Literature DB >> 32363133 |
Leandro Pecchia1,2, Davide Piaggio1, Alessia Maccaro1, Claudio Formisano3, Ernesto Iadanza2,4.
Abstract
COVID-19 pandemic is plaguing the world and representing the most significant stress test for many national healthcare systems and services, since their foundation. The supply-chain disruption and the unprecedented request for intensive care unit (ICU) beds have created in Europe conditions typical of low-resources settings. This generated a remarkable race to find solutions for the prevention, treatment and management of this disease which is involving a large amount of people. Every day, new Do-It-Yourself (DIY) solutions regarding personal protective equipment and medical devices populate social media feeds. Many companies (e.g., automotive or textile) are converting their traditional production to manufacture the most needed equipment (e.g., respirators, face shields, ventilators etc.). In this chaotic scenario, policy makers, international and national standards bodies, along with the World Health Organization (WHO) and scientific societies are making a joint effort to increase global awareness and knowledge about the importance of respecting the relevant requirements to guarantee appropriate quality and safety for patients and healthcare workers. Nonetheless, ordinary procedures for testing and certification are currently questioned and empowered with fast-track pathways in order to speed-up the deployment of new solutions for COVID-19. This paper shares critical reflections on the current regulatory framework for the certification of personal protective equipment. We hope that these reflections may help readers in navigating the framework of regulations, norms and international standards relevant for key personal protective equipment, sharing a subset of tests that should be deemed essential even in a period of crisis.Entities:
Keywords: CE marking; COVID-19; Face-shields; International standards; Masks; Personal protective equipment; Visors
Year: 2020 PMID: 32363133 PMCID: PMC7195610 DOI: 10.1007/s12553-020-00429-2
Source DB: PubMed Journal: Health Technol (Berl) ISSN: 2190-7196
The subset of tests (EN 166) deemed essential to evaluate personal eye protection equipment for COVID-19
| Performance requirement | Test method clause | Requirement |
|---|---|---|
| General construction (Section 6.1 EN 166:2002) | Visual inspection and manufacturer’s certificates | Eye-protectors shall be free from projections, sharp edges or other defects which are likely to cause discomfort or injury during use. |
| Materials (6.2) | Visual inspection and manufacturer’s certificates | No parts of the eye-protector which are in contact with the wearer shall be made of materials which are known to cause any skin irritation. |
| Headbands (6.3) | By measuring | Headbands, when used as the principal means of retention, shall be at least 10 mm wide over any portion which may come into contact with the wearer’s head. Headbands shall be adjustable or self-adjusting. |
| Field of vision (7.1.1) | The size of the field of vision is defined in conjunction with the appropriate head-form described in clause 17 of EN 168:2001. The test shall be carried out in accordance with clause 18 of EN 168:2001. | Eye-protectors shall exhibit a minimum field of vision defined by the two ellipses when placed and centered at a distance of 25 mm from the surface of the eyes of the appropriate head-form. The horizontal axis shall be parallel to and 0,7 mm below the height of the line connecting the centres of the two eyes. |
| The horizontal length of the ellipses shall be of 22.0 mm, the vertical width of the ellipses shall be 20.0 mm. The centre distance of the two ellipses shall be d = c + 6 mm, where c is the pupillary distance. The pupillary distance is 64 mm for the medium head-form and 54 mm for the small head-form, if not specified differently by the manufacture. | ||
| Spherical, astigmatic and prismatic refractive powers (7.1.2.1) | The refractive powers of oculars shall be measured by the reference methods specified in clause 6 of EN ISO 18526-1:2020. If, during measurement using the telescope, a doubling or other aberration of the image is observed, then the test sample shall be subjected to further examination using the test method described in 6.3 of EN ISO 18526-1:2020 | The permissible tolerances for oculars without corrective effect are given in the Clause 7.1.2.1.2 of EN166. |
| Transmittance – oculars without filtering action (7.1.2.2–1) | Clause 6 of EN ISO 18526-2:2020 | Oculars intended to protect the eyes against mechanical or chemical hazards only, and cover plates, shall have a luminous transmittance greater than 74.4%. |
| Diffusion of light (7.1.2.3) | Clause 14 of EN ISO 18526-2:2020 | The max value of the reduced luminance factor shall be 0.50 cd/(m2*lx) for all the other oculars. |
| Quality of material and surface (7.1.3) | Clause 6.6 of EN ISO 18526-3:2020 | Except for a marginal area 5 mm wide, oculars shall be free from any significant defects likely to impair vision in use, such as bubbles, scratches, inclusions, dull spots, pitting, mould marks, scouring, grains, pocking, scaling and undulation. |
| Minimum robustness (7.1.4.1) | Clause 3.1 of EN 168:2001 | The 7.1.4.1 requires performing an impact test with a 22 mm nominal diameter steel ball, impacting with a force of (100 ± 2) N. |
| On so testing the following defects shall not occur: | ||
| a) ocular fracture: an ocular shall be considered to have fractured if it cracks through its entire thickness into two or more pieces, or if more than 5 mg of the ocular material becomes detached from the surface away from the one in contact with the ball, or if the ball passes through the ocular; | ||
| b) ocular deformation: an ocular shall be considered to have been deformed if a mark appears on the white paper on the opposite side to the one on which the force is applied. | ||
| Note: in period of crisis such as the COVID, this should be at least tested using realistic simulations | ||
| Resistance to corrosion (7.1.6) | Clause 6.9 of EN ISO 18526-3:2020 | After the test, all metal parts of the eye-protector shall display smooth surfaces, free from corrosion, when they are examined by a trained observer. |
| Note: This should be extended to plastic parts considering the sterilization processes and substances (e.g., after cleaning visibility should not be compromised) | ||
| Resistance to ignition (7.1.7) | Clause 6.10 of EN ISO 18526-3:2020 | Eye-protectors shall be considered to be satisfactory if no part of the eye-protector ignites or continues to glow after removal of the steel rod. |
| Protection against (droplets) and splashes of liquid (7.2.4) | Clause 12 of EN 168:2001 | Face-shields cover the eye-region rectangle of the appropriate head-form as described in 10.2.2.2 of EN 168:2001 as assessed in accordance with 10.2 of EN 168:2001. Additionally, face-shields for protection against splashes of liquids shall have a viewing area with a minimum vertical centre-line depth of 150 mm when mounted in the appropriate housing. |
| Lateral protection (7.2.8) | Clause 6.4 of EN ISO 18526-3:2020 | Eye-protectors claimed to provide lateral protection shall pass the lateral region coverage assessment |
| Resistance to fogging (7.3.2) | Clause 6.11 of EN ISO 18526-3:2020 | If oculars are described as resistant to fogging they shall remain free from fogging for a minimum of 8 s when tested. |
The subset of tests (EN 149:2001 + A1:2009) deemed essential to evaluate respiratory protective devices for COVID-19
| Performance requirement | Test method clause | Requirement |
|---|---|---|
| Visual inspection (Section 7.3 EN 149:2001 + A1:2009) | The visual inspection is carried out where appropriate by the test house prior to laboratory or practical performance tests (Clause 8.2). | |
| Packaging (7.4) | The visual inspection is carried out where appropriate by the test house prior to laboratory or practical performance tests (Clause 8.2). | Particle filtering half masks shall be offered for sale packaged in such a way that they are protected against mechanical damage and contamination before use. |
| Cleaning and disinfecting (7.6) | Testing shall be done in accordance with Clause 8.4 and Clause 8.5. With reference to 7.9.2, after cleaning and disinfecting the re-usable particle filtering half mask shall satisfy the penetration requirement of the relevant class. Testing shall be done in accordance with Clause 8.11. | After cleaning and disinfecting the re-usable particle filtering half mask shall satisfy the penetration requirement of the relevant class. |
| If the particle filtering half mask is designed to be re-usable, the materials used shall withstand the cleaning and disinfecting agents and procedures to be specified by the manufacturer. | ||
Practical performance (7.7) The particle filtering half mask shall undergo practical performance tests under realistic conditions. | 2 particle filtering half masks shall be tested as received in accordance with Clause 8.4. | During the tests the particle filtering half mask shall be subjectively assessed by the wearer and after the test, comments on the following shall be recorded: |
| a) head harness comfort; | ||
| These general tests serve the purpose of checking the equipment for imperfections that cannot be determined by the tests described elsewhere in this standard. | ||
| b) security of fastenings; | ||
| c) field of vision; | ||
| d) any other comments reported by the wearer on request. | ||
| Where practical performance tests show the apparatus has imperfections related to wearer’s acceptance, the test house shall provide full details of those parts of the practical performance tests which revealed these imperfections. | ||
Total inward leakage (7.9.1) The laboratory tests shall indicate that the particle filtering half mask can be used by the wearer to protect with high probability against the potential hazard to be expected. The total inward leakage consists of three components: face seal leakage, exhalation valve leakage (if exhalation valve fitted) and filter penetration. | At least 5 specimens shall be tested as received in accordance with Clause 8.5. | All samples must achieve the specifics. |
| All individual exercise results tests shall be not greater than 11% (FFP2) (5% for FPP3) and, in addition, all arithmetic means for the total inward leakage shall be not greater than 8% (FFP2) (2% for FFP3). | ||
| Penetration of filter material (7.9.2) | At least 3 samples shall be tested as received for NaCl and paraffin oil (PO) for 3 min in accordance with Clause 8.11. | The maximum penetration of test aerosol shall be: • 6% for both PO and NaCl for FFP2 • 1% for both PO and NaCl for FFP3 |
| Carbon dioxide content of the inhalation air (7.12) | At least 3 particle filtering half masks shall be tested in accordance with Clause 8.7. | The carbon dioxide content of the inhalation air (dead space) shall not exceed an average of 1.0% (by volume). |
| Head harness (7.13) | Testing shall be done in accordance with Clause 8.4 and 8.5. | The head harness shall be designed so that the particle filtering half mask can be donned and removed easily. The head harness shall be adjustable or self-adjusting and shall be sufficiently robust to hold the particle filtering half mask firmly in position and be capable of maintaining total inward leakage requirements for the device. |
| Field of vision (7.14) | Testing shall be done in accordance with Clause 8.4. | The field of vision is acceptable if determined so in practical performance tests. |
| Breathing resistance (7.16) | At least 3 samples shall be tested as received in accordance with Clause 8.9. | The maximum permitted resistances per volumetric flow rate for FFP2 are: |
| • 30 l/min – 0.7 mbar (inhale) | ||
| • 95 l/min – 2.4 mbar (inhale) | ||
| • 160 l/min – 3.0 mbar (exhale) | ||
| For FFP3 are: | ||
| • 30 l/min – 1.0 mbar (inhale) | ||
| • 95 l/min – 3.0 mbar (inhale) | ||
| • 160 l/min – 3.0 mbar (exhale) |