Technical
Contents
Testing Standards and Requirements
ISC Technology Readiness Level Scale
ISC is Innovative Solutions Canada They have a chart that defines the stages of development. Technology Readiness Levels (TRL) describe the different stages of pre-commercial development. Find TRL 1 to 9 definitions, descriptions and examples.
Currently 2020-4-17 at between levels 5.TRL and 6.TRL . Funding is looking for projects in the 7.TRL to 9.TRL
Standard Sizes
ISO Digital Headform Sizes
The National Personal Protective Technology Labratory (NPPTL) has NIOSH Anthropometric Data and ISO Digital Headforms available in .stl .ply and .igs format. The five nominal sizes are:
- Small
- Medium
- Large
- Long/Narrow
- Short/Wide
The headforms will be available from NIOSH for those who complete the data use agreements. To obtain the digital headforms or more information, please contact Dr. Ziqing Zhuang at ZZhuang1@cdc.gov .
This ISO standard is available for purchase ISO/TS 16976-2:2015(en) Respiratory protective devices — Human factors — Part 2: Anthropometrics
This ISO standard is available online and for free as part of the Covid19 response ISO/TS 16976-8:2013(en) Respiratory protective devices — Human factors — Part 8: Ergonomic factors
NIOSH Testing Procedure Head Classifaction Size
The Facepiece Fit Test procedure requires the participants to be classified by size and provides a chart and a procedure to classify the 10 different sizes. See pages 10 and 11 of the Determination of Qualitative Isoamyl Acetate (IAA) Facepiece Fit Test
Current Parametric Dimensions of Sizes
Using the Table 5 from ISO/TS 16976-2 for the Mean Sizes of the "5 defined headforms"
I made the following assumptions:
- Mask Width = 70% of Face Width
- Mask Height = Face Height - 40% of Nose Height - 70% of Mouth to Chin Height
- Mask Depth = 40% of Face Width
| # | Size | Face Height | Face Width | Mask Height | Mask Width | Half Width | Mask Depth | Connector Size | Connector Height |
|---|---|---|---|---|---|---|---|---|---|
| 21 | Small | 4.3" | 5.0" | 2.47" | 3.53" | 1.76" | 1.41" | 1.00" | 0.70" |
| 31 | Short Wide | 4.6 | 5.0" | 2.60" | 3.89" | 1.94" | 1.55" | ||
| 51 | Medium | 4.7" | 5.5" | 2.71" | 3.86" | 1.93" | 1.54" | 1.40" | 0.75" |
| 71 | Tall Narrow | 5.0" | 5.5" | 2.86" | 3.86" | 1.93" | 1.54" | ||
| 81 | Large | 5.0" | 5.7" | 2.92" | 4.02" | 2.01" | 1.61" |
Contact with Skin
The standard is available for free as part of the COVID response ISO 10993-1:2018 Biological Evaluation Of Medical Devices - Part 1: Evaluation And Testing Within A Risk Management Process
This document applies to evaluation of materials and medical devices that are expected to have direct or indirect contact with:
— the patient's body during intended use;
— the user's body, if the medical device is intended for protection (e.g., surgical gloves, masks and others).
Filter Requirements
N95 Specifications
The buyandsell.gc.ca website has the technical requirements for the N95 masks I created a screen capture of the table at this link
| N95 Spec | Typical |
|---|---|
| Filter Performance | >=95% |
| Test Agent | NaCl |
| Flow Rate | 85 l/min |
| Inward leakage | <=8% |
| Inhalation Resistance | <=343 Pa |
| Flow Rate | 85 l/min |
| Exhalation Resistance | <=245 Pa |
Suppliers
Freudenburg Filtration Technologies
649 Wilton Grove Rd, London, ON N6N 1N7 (519) 686-9888 https://www.freudenberg-filter.com/en/
Called on 2020-4-21 and left a message for engineering.
Dynamic Filtration Ltd
DYNAMIC FILTRATION, LTD. 55 Bathurst Dr., Waterloo Ontario, Canada N2V 1N2 Toll Free: 800.265.4544 Phone: 519.886.0749 Fax: 519.884.4390 http://www.dynamicfiltration.ca/
Sent a request a quote form on 2020-4-21 with a .pdf picture of Mask with cord with the following information.
Hello I have designed a mask filter holder and I am looking for a suitable filter material. The goal is to create a mask that can both trap a cough, or any water droplets coming out of the mouth and also prevent anything foreign from getting in the mouth or nose. I have a website that explains more about the project. Thank you for you time and any information you can provide. Your assistance is appreciated. Michael
Stephanie promptly replied with:
Hi Michael, Thanks for your email. Unfortunately this is not something we can be involved in or supply to you. We don't service any facet of the healthcare industry, nor do we have a media that would provide adequate capture for moisture droplets. I do wish you good luck in your search, this is definitely an admirable undertaking! Best, Stephanie Gaber General Manager
Dafco Filtration Group
5390 Ambler Dr Mississauga, ON L4W 1G9 Canada Contact: Kevin Cinel Phone: 1 888 628-3458 Email: KCINEL@FILTRATIONGROUP.COM
Hello Kevin I have designed a mask filter holder and I am looking for a supplier of suitable filter material. The goal is to create a mask that can both trap a cough, or any water droplets coming out of the mouth and also prevent anything foreign from getting in the mouth or nose. The goal is to thermoform these holders at a rate of 20,000 per 8 hour shift. Each filter uses about 1/4 sq.ft. so I will require bout 5000 sq.ft per day. I have a website that explains more about the project. www.mvrdesigns.ca/mask The N95 mask requirements are: (insert N95 Table) The current filter area is 10 sq.in. Do you have any materials that can achieve (or come close) to these specs? Thank you for you time and any information you can provide. Your assistance is appreciated. Michael
Face Fit Test Procedures
The CDC has Standard Respirator Testing Procedures has test procedures for:
- TEB-APR-STP-0005, 0005a, and 0006Cdc-pdf Determination of Qualitative Isoamyl Acetate (IAA) Facepiece Fit Test
- RCT-APR-STP-0067Cdc-pdf Particulate Respirator Qualitative Fit Test Utilizing Saccharin or Bitrex Solutions
Test in Cough Chamber
Found this article on web Scientists built 'cough chamber' to see how far droplets actually travel
What researchers at Western University, in collaboration with virologists from Toronto's Sunnybrook Hospital, found is that when someone coughs without covering their mouth, the germ-laden cloud of fine mist they release will not only travel two metres in three seconds, it will continue to travel beyond and even float in the air within that two-metre area for up to three minutes after being released.
Need to find out if they can test our masks.
