Fit Factor & Impact Calculator

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1	Mask/Respirator Fit Testing - Fit Factor & Impact Calculator
2	Created by:	Dr. Jeff Gilchrist
3	Last updated:	May 7, 2023
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5	Link to this calculator:	https://tinyurl.com/y442j3wm
6	Background information on quantitative fit testing:	https://twitter.com/jeffgilchrist/status/1652390822061527043
7	How do masks actually filter tiny particles like viruses?	https://twitter.com/jeffgilchrist/status/1602994049815908353
8	COVID-19 guides, useful info & 600+ scientific articles:	http://covid.gilchrist.ca/
9	For my daily COVID-19 related statistics and graphs:	http://covid.gilchrist.ca/Ottawa.html			http://covid.gilchrist.ca/Ontario.html
10	Fit testing video resources:	https://www.youtube.com/@FitTestThePlanet/videos				https://www.youtube.com/@gerardhughes/videos
11	Fit testing/respirator Twitter resources:	https://twitter.com/FitTestMyPlanet			https://twitter.com/ghhughes		https://twitter.com/sameo416
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13	NOTE: To change the values in this calculator you first need to make a copy by selecting "File -> Make a copy" within Google Sheets which will then let you edit the values.
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15	Overall Fit Factor (FF) score is the harmonic mean of the results which gives higher weight to lower scores. Since this is a safety application, you want to weigh the lower scores
16	more heavily to be more realistic than have the easier to pass test (normal breathing) artificially increase an average.
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18	Harmonic Mean calculation formula (where N is the # of tests): N / ((1/FF_Score1) + (1/FF_Score2) + ... + (1/FF_ScoreN))					(Video explanation: https://www.youtube.com/watch?v=wHNIgNoC9lw )
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20			Harmonic Mean Overall Fit Factor Calculator:
21	Exercise	Duration (sec)	Fit Factor (FF)
22	Normal Breathing	30	835
23	Deep Breathing	30	502
24	Turn Head Side To Side	30	559
25	Nod Head Up and Down	30	530
26	Talk Out Loud	30	245
27	Bending Over	30	679
28	Normal Breathing	30	724
29		Overall FF score (harmonic mean):	507
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31	* the sample results in the calculator are my respirator Fit Testing results using a 3M Aura 9205+.
32	Change the Fit Factor (FF) values for each test in the calculator to see the impact on overall FF results.
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35				Real-World Impact Calculator of Various Fit Factors:
36	Scenario: you are in a poorly ventilated location with sick people who are breathing enough infectious aerosols into the air
37	so that it would take an unmasked person X minutes to breathe in enough virus to become infected.
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39	Time to infection without a mask (minutes):	5
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41	Fit Factor (FF)	Time (minutes)	Time (hours)	Comments
42	2	10	0.2	Procedure mask "baggy blue" typical FF is 2-3
43	5	25	0.4	Ear loop masks typical FF is 2-10
44	10	50	0.8
45	15	75	1.3
46	25	125	2.1
47	50	250	4.2
48	75	375	6.3
49	100	500	8.3	Minimum FF to pass N95 fit test is 100
50	200	1000	16.7
51	400	2000	33.3
52	500	2500	41.7	My 3M Aura 9205+ overall FF score was 507
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54	* Time (minutes and hours) is the equivalent exposure time needed vs the time to exposure without a mask at the specified fit factor (FF).
55	Change the "Time to exposure without a mask (minutes)" value and "Fit Factor (FF)" values for the desired scenario you are interested in comparing.
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