The Science

Fog Fan Solution is our brand name for the Flavobac concentrate which is produced by Citrox Biosciences Ltd, Cambridge, UK and has been on the UK market for nearly 20 years.

Fog Fan Solution inactivates 99.9% of pathogens (fungi, bacteria, viruses). These include coronaviruses, the common cold, influenza, rhinovirus, HIV and norovirus. Pathogens tested and relevant EN standards are shown below:

VIRUSES

  1. SARS-CoV-2 Coronavirus
    University of Utah (Salt Lake City, UT, USA), 2020
  2. Influenza Virus
    Retroscreen Virology Ltd and Biobest Laboratories Ltd (UK), 2009
  3. Norovirus
    Biological Solutions LLC (Sumter, SC, USA), 2006
  4. SARS Virus
    Retroscreen Virology Ltd, Barts & The LQMS (UK), 2004
  5. Human Influenza A Virus
    Retroscreen Virology Ltd, Barts & The LQMS (UK), 2004
  6. Human Rhinovirus-16
    Retroscreen Virology Ltd, Barts & The LQMS (UK), 2004

BACTERIA

  1. Campylobacter Jejuni - NCTC11322
    Abbott Analytical Ltd (Birkenhead, UK), 2020
  2. Clostridium difficile - ATCC11437 using EN13704
    Abbott Analytical Ltd (Birkenhead, UK), 2020
  3. Clostridium perfringens - EN13704
    Abbott Analytical Ltd (Birkenhead, UK), 2020
  4. Enterococcus Faecalis - NTC 8213
    Abbott Analytical Ltd (Birkenhead, UK), 2020
  5. Lactobacillus acidophilus - ATCC4356 using modified EN1276
    Abbott Analytical Ltd (Birkenhead, UK), 2020
  6. Legionella pneumophila - EN1276
    Abbott Analytical Ltd (Birkenhead, UK), 2020
  7. Listeria on surfaces using an Electrostatic sprayer giving 20 micron droplet size
    Abbott Analytical Ltd (Birkenhead, UK), 2020
  8. Penicillium digitatum - EN1650
    Abbott Analytical Ltd (Birkenhead, UK), 2020
  9. Mycobacterium fortuitum - EN1276
    Abbott Analytical Ltd (Birkenhead, UK), 2020
  10. Phytophthora ramorum - EN 1650
    Abbott Analytical Ltd (Birkenhead, UK), 2020
  11. Pseudonomas aeruginosa - ATCC15442 using BSEN1276
    Abbott Analytical Ltd (Birkenhead, UK), 2020
  12. Escherichia coli - NCTC10418 using BSEN1276
    Abbott Analytical Ltd (Birkenhead, UK), 2020
  13. Staphylococcus aureus - NCTC 6571 using BSEN 1276
    Abbott Analytical Ltd (Birkenhead, UK), 2020
  14. Enterococcus hirae - ATCC 8043 using BSEN1276
    Abbott Analytical Ltd (Birkenhead, UK), 2020
  15. Vibro parahaemolyticus using modified EN1276
    Abbott Analytical Ltd (Birkenhead, UK), 2020


FUNGI

  1. Quantitative suspension test for the evaluation of fungicidal or yeasticidal activity - EN13624
    Abbott Analytical Ltd (Birkenhead, UK), 2020

 

BACTERIA

See the table below which shows the time it takes Fog Fan Solution to inactivate different strains of bacteria.

“Log” is short for logarithm. A 1 Log reduction means a 10 fold (one decimal place) or 90% reduction. A 2 log reduction means a further 10 fold, for a total of 99%, and so on.

Bacteria

Required Time (mins) Log reduction

Campylobacter jejuni
NCTC 11322 under dirty conditions

5 mins 4

Clostridium difficile 
ATCC 11437 using EN 13704 under dirty conditions

30 mins 4

Clostridium perfringens
Using EN13704 under dirty conditions

30 mins 4

Enterococcus Faecalis
NTC 8213 under dirty conditions

5 mins 4

Lactobacillus acidophilus
ATCC 4356 using modified EN 1276 under dirty conditions

5 mins 5

Legionella pneumophila
using EN 1276

1 mins 5

Legionella pneumophila
using EN 1276

1 mins 5

Listeria
On surfaces using an Electrostatic sprayer giving 20 micron droplet size

5 mins 4

Penicillium digitatum
Using adaptation of EN 1650

5 mins 4

Mycobacterium fortuitum
Using EN 1276

1 mins 5

Phytophthora ramorum
Using adaptation of EN 1650

5 mins 4

Pseudomonas aeruginosa
ATCC 15442 using BSEN 1276 under dirty conditions

5 mins 5

Escherichia coli
NCTC 10418 using BSEN 1276 under dirty conditions

5 mins 5

Staphylococcus aureus
NCTC 6571 using BSEN 1276 under dirty conditions

5 mins 5

Enterococcus hirae
ATCC 8043 using BSEN 1276 under dirty conditions

5 mins 5

Vibro parahaemolyticus
using modified EN 1276 under dirty conditions

5 mins 5

  

Misting with Fog Fan Solution is effective against airborne viruses

Research was carried out by Aerosol Research Engineering, Inc (Olathe, KS, USA), in November 2020. FanFog Orange solution was misted into a 1 metre cube. At the same time MS2 Bacteriophage was introduced to the chamber. MS2 Bacteriophage surrogate is a small, non-enveloped, icosohedral virus considered harder to kill than SARS-CoV-2.

In the first test we ran a 3 minute burst. In total 10mls of Fog Fan concentrate solution was misted and fanned over the 3 minutes. The results were as follows:

  • Within 5 minutes there was a 57% reduction in MS2 Bacteriophage
  • By 30 minutes there was an 89% reduction MS2 Bacteriophage

In the second test we misted and fanned continuously for 60 minutes, a total of 200mls of FanFog Orange solution. The results were as follows:

  • By the 30 minute point there was a 99.9985% reduction in MS2 Bacteriophage.

 

The test chamber - before and after:

 

And here are the results:

 

Droplets size and airborne time

It is important to consider airborne time / settle time as both the smaller a virus the longer it will stay airborne. For example SARS-CoV-2 is particularly small at approximately 0.1micron diameter and studies show stays airborne for more than 5 hours all other factors being equal. See table below for some examples of droplet size and airborne time.

Droplet size (microns)

Airborne/Time to settle

Speech

12 – 21

8 – 14 minutes

SARS-CoV-2

0.06 - 0.14

3-12 hours

Fog Fan Solution

4 – 5

30 – 90 minutes

 

Humidity

We know from simulations run on the Fugaku supercomputer here how SARS-CoV-2 spreads in the air as a ‘plume’. Increasing the humidity reduces the spread as the water vapour aggregates with the viral particles and these heavier clumps fall to the floor more quickly. The water vapour essentially takes them out of the air. Increasing the humidity in a room from 30% to 60% alone reduces the spread of SARS-CoV-2 by 50%. The climate in the UK is Temperate Maritime & humidity varies by season. See table below.

HUMIDITY

Temperate Maritime - Winter

40-50 %

Temperate Maritime - Summer

50-60 %


Volume of water in air

Humidity is the volume of water held in air. It increases as temperature increases. For instance for 40% humidity at 20°C/68°(room temperature) there will be 6.9mls of water in each one cubic metre of air. To increase the humidity to 60% at the same temperature we would need to dissolve a furthers 3.5mls into each cubic metre of air. The table below shows this in more detail where EMT refers to the estimated misting time for 1ml of water from the table below. I.e. If we know it takes 12mins to dissolve 1ml of water into a 40m³ room it will take 3.5 times this amount to dissolve 3.5mls into 40m³ of air.

Temp C

Volume for 100% humidity (ml)/m³

Volume at 40% (ml)

Volume at 60% (ml)

Time to increase humidity from 40-60%

15

12.8

5.1

7.7

EMT x 2.6

20

17.3

6.9

10.4

EMT x 3.5


Estimated misting time

How long should you mist for? Here we need to consider the time it takes to fill the room with the necessary amount of Fog Fan Solution. We have based these calculations on increasing the water content of each cubic metre of air in the room by 1ml. This should be the minimum. The below calculations assumes the fan misting at 200mls per hour which is 3.33mls of Fog Fan Solution per minute.

 

Size – m³

Estimated misting time

Recommended no of Fog Fans

Average living room

40

12 mins

1

Hairdressing Salon

60

18 mins

1

Meeting room

80

24 mins

1

Classroom

150-200

22 - 30 mins

2

Restaurant

150-400

22 - 60 mins

2



Comparison of alternate systems

Fog Fan Solution has met the criteria for multiple EN and EPA standards for its ability to inactivate bacteria, viruses and fungi as described above. What sets it apart from other antimicrobials is its safety record. See table below for comparison of other room
sanitising products available on the market.

You can download the PDF version here.

NOTES:

(1) Hypochlorous Acid (HOCl) damages pathogens via oxidative stress caused by monovalent chlorine. By the same mechanism of oxidation it can also react with lung and skin molecules and lipids causing oxidative stress and contributing to inflammatory disease. It can react with unsaturated organic compounds producing chlorohydrins and reactive oxygen species, and finally it can react with molecules in the air causing toxic gases such as C12.

(2) Sodium Hypochlorite (NAOCl) solution, commonly known as bleach, is an irritant and is corrosive, necessitating the use of PPE.

(3) Ozone is a pollutant and respiratory hazard causing airway constriction. It cannot be stored or transported in vessels because it decomposes spontaneously in the presence of oxidisable impurities, humidity and solid surfaces. It is always generated in situ, for immediate use.

(4) UV-C light is unsafe for humans, plants and animals and only works in line of sight.

 

References

(1) https://www.scirp.org/(S(i43dyn45teexjx455qlt3d2q))/journal/paperinformation.aspx?paperid=68109

(2) https://www.medrxiv.org/content/10.1101/2020.05.12.20099630v1.full.pdf

(3) https://www.pnas.org/content/117/22/11875

(4) https://www.nejm.org/doi/full/10.1056/NEJMc2004973

(5) https://www.ncbi.nlm.nih.gov/books/NBK143281/

(6) https://www.nature.com/articles/sj.bdj.2010.1224

(7) https://pubmed.ncbi.nlm.nih.gov/11327319/