Skip to main content

Nano Spray Machine

Under COVID-19, people try their best to disinfect. Many tools appeared in the market for disinfection. In Hong Kong, atomizing spray guns are one of the most common in the market. Most of them are also marked as blue light nano spray, which advertises large fog volume, fine atomization, a long-range, and a wide range of uses. However, can any cleaners be used with the atomizing spray gun? In this project, I will figure out how the air quality changes after using an atomizing spray gun.

I tried experimenting with the most common cleaners to see how air quality changes, which included alcohol, 1:99 diluted household bleach, and chloroxylenol. 

Common cleaners

First of all, to figure out the effect of atomizing spray guns on changes in air quality. I made a box to simulate a sealed space for measurements.

Then, I add different cleaners to the atomizing spray gun and turn it on for 10 seconds.

Monitoring Air Quality in a confined space

Next, monitor changes in the air quality kit readings. Below are the results.

Alcohol

Air Quality Display for Alcohol - Screen 1

Air Quality Display for Alcohol - Screen 2

 

Normal

Peak

Difference

Peak to normal time

TVOC

100

373

273

15:47:00 - 15:55:00

PM1.0

4

196

192

15:47:00 - 16:09:30

PM2.5

4

244

240

15:47:00 - 16:09:30

PM4.0

5

275

270

15:47:00 - 16:09:30

PM10

5

289

284

15:47:00 - 16:09:30

1:99 diluted household bleach

Air Quality Display for Bleach - Screen 1

Air Quality Display for Bleach - Screen 2

 

Normal

Peak

Difference

Peak to normal time

TVOC

95

198

103

16:37:45 - 16:53:00

PM1.0

316

1814

1498

-

PM2.5

460

3825

3365

-

PM4.0

564

5406

4842

-

PM10

612

6141

5529

-

Chloroxylenol

Air Quality Display for Chloroxylenol - Screen 1

Air Quality Display for Chloroxylenol - Screen 2

 

Normal

Peak

Difference

Peak to normal time

Time needed

TVOC

100

454

354

15:47:45 - 16:00:00

12 mins. 15 sec.

PM1.0

1

1168

1167

15:47:45 - 18:30:00

2 hrs. 42 mins. 15 sec.

PM2.5

2

3378

3376

15:47:45 - 18:30:00

2 hrs. 42 mins. 15 sec.

PM4.0

2

5155

5153

15:47:45 - 18:30:00

2 hrs. 42 mins. 15 sec.

PM10

2

5981

5878

15:47:45 - 18:30:00

2 hrs. 42 mins. 15 sec.

 

Alcohol

   

1:99 diluted household bleach

   

Chloroxylenol

   
 

Normal

Peak

Difference

Normal

Peak

Difference

Normal

Peak

Difference

TVOC

100

373

273

95

198

103

100

454

354

PM1.0

4

196

192

316

1814

1498

1

1168

1167

PM2.5

4

244

240

460

3825

3365

2

3378

3376

PM4.0

5

275

270

564

5406

4842

2

5155

5153

PM10

5

289

284

612

6141

5529

2

5981

5878

Air Quality Change Graph

Before we move on to the result, let's take a look at what is TVOC and PM first.

Total volatile organic compounds (TVOC)

According to the "Indoor Air Quality Guidelines for selected Volatile Organic Compounds (VOCs) in the UK" - Total volatile organic compounds (TVOC) is the sum of the concentrations of the identified and unidentified volatile organic compounds, as specified in the Standard. VOCs are widely used in construction and building products (eg paints, varnishes, waxes, solvents), in household consumer products (detergents, cleaning products, air fresheners and personal care products) and are also emitted while using electronic devices such as photocopiers or printers. Health Organisations (eg The World Health Organization, The US Environmental Protection Agency, PHE) have assessed the evidence and listed the health impacts of VOCs, which include irritation of the eyes and respiratory tract, allergies and asthma, central nervous system symptoms, liver and kidney damage, as well as cancer risks.

(https://www.gov.uk/government/publications/air-quality-uk-guidelines-for-volatile-organic-compounds-in-indoor-spaces)

Index Category Index Value TVOC (ppb)
Good 0 - 50 0 - 220
Moderate 51 - 100 221 - 560
High 101 - 150 661 - 1430
Very High 151 - 200 1431 - 2200
Very High 201 - 300 2201 - 3300
Very High 301 - 500 3301 - 550

By Kaiterra (https://learn.kaiterra.com/en/resources/understanding-tvoc-volatile-organic-compounds)

Particulate matter (PM)

According to the UKGOV - Concentrations of particulate matter (PM10 and PM2.5), particulate matter (PM) is everything in the air that is not a gas and therefore consists of a huge variety of chemical compounds and materials, some of which can be toxic. Due to the small size of many of the particles that form PM some of these toxins may enter the bloodstream and be transported around the body, lodging in the heart, brain, and other organs. Therefore, exposure to PM can result in serious impacts on health, especially in vulnerable groups of people such as the young, elderly, and those with respiratory problems. As a result, particulates are classified according to size.

The Air Quality Standards Regulations 2010 require that concentrations of PM in the UK must not exceed:

  • An annual average of 40 µg/m3 for PM10;
  • A 24-hour average of 50 µg/m3 more than 35 times in a single year for PM10;
  • An annual average of 20 µg/m3 for PM2.5.

(https://www.gov.uk/government/statistics/air-quality-statistics/concentrations-of-particulate-matter-pm10-and-pm25)

In simple words, a high level of TVOC or PM level can result in serious impacts on health.

The above results show that the time needed for alcohol TVOC levels to go from peak levels to normal levels is the fastest (8 mins), followed by Chloroxylenol (12 mins. 15 sec.) and Bleach 1:99 (15 mins. 15 sec.).

We can see that, after we atomization the alcohol, the index increased to 373, which is a very high level. Although the alcohol TVOC levels only needed a short period of time to go from peak levels to normal levels, which definitely is not a suitable cleaner for atomization. For Chloroxylenol, the index of TVOC after it atomized also increased by 354, hence Chloroxylenol also isn’t a suitable cleaner for atomization. Although 1:99 diluted household bleach has a lower TVOC index than the other two because bleach is alkaline and can irritate the respiratory tract and skin cells if inhaled. Hence, diluted household bleach also isn’t a suitable cleaner for atomization. Therefore, we can see that all of the above cleaners are not suitable cleaners to atomized.

At the same time, we can see an interesting finding that PM levels are very low after alcohol atomization. This is because the alcohol is volatile, therefore the PM level of the alcohol is significantly lower than others.

So, when we are choosing the cleaner for atomization, we should carefully choose the ones marked atomization allowed. Then, we can use it more efficiently and safely.

JulianWong has not written a bio yet…