Washing your hands with soap is known to be even more effective than using a hand sanitizer but it is often impractical when you are not at home, especially when you don’t want to use a public toilet which can lead to the spread of infection. In such public settings, it is much more convenient and perhaps even safer to use a hand sanitizer. Because of this the demand and production of hand sanitizer has gone through the roof and hundreds and thousands of new bands of sanitizer have come into the market. Unfortunately all hands advertisers are not made to the same quality standard And numerous unscrupulous manufacturers are resorting to selling of standard hand sanitizers to increase their profit.
The main ingredient of the hand sanitizer and the main costs of manufacturing comes from the alcohol content of the product. The World Health Organisation recommends that hand sanitizer should contain 70% to 90% of alcohol for them to be effective against covid-19.
Greed is putting us all at risk!
Just to earn a little more money some sanitizer manufacturers are not adding the required amount of alcohol and some are given selling plain water with fragrance and some are even selling plain water with fragrance and thickener added to it.
What is the industrial method for testing alcohol content in sanitizer?
The recommended testing method for determining the quantity of alcohol in sanitizer is by gas chromatography, All manufacturers of Hand sanitizer are required to test each and every batch of their product for alcohol content by using this technique. Unfortunately, this requires a piece of sophisticated equipment which costs tens of thousands of dollars and most of the manufacturers don’t even have this equipment. Quality conscious and good manufacturers who do not have gas chromatography equipment work with contract testing labs where they send their product for testing to ensure the quality of the product.
Still, the testing of sanitizer is expensive and out of the reach of consumers and retailers who might be using just using a few bottles and the cost of testing will be more than the cost of the product. Just getting one sample tested can cost up to 300 Rupees (40 USD). Rampant sale of poor quality hand sanitizer has really worried me and I decided to work to develop simple tests which can be done at home very quickly and at almost no cost to the consumer. So now that we have enough background let’s jump into answering the question “How to test a hand sanitizer at home?”.
What material do you need for testing hand sanitizer at home?
For testing the hand sanitizer at home you need very commonly available items listed below –
- Roll of tissue paper (toilet paper)
- Ballpoint pen – please make sure that the ballpoint pen you use for conducting this test Is not water washable. We have tried with Reynolds and their pens work just fine and are readily available in most homes or offices. Please do not use a Gel pen or an ink pen.
- Anything with you can draw a nice small circle a coin or even the cap of your sanitizer bottle can work just fine.
- Half cup of wheat flour
- Some plates and bowls
- A hair dryer
With these commonly available items you can easily conduct all three tested detailed below –
The Tissue paper test or Toilet paper test for Hand Sanitizer
- Take a small piece of tissue paper and keep it on a flat surface like a table or kitchen counter. It is important that you do not make a thick wadd of the tissue paper as you want the sanitizer to defuse sideways only and not down into the tissue paper.
- Use a ballpoint pen and carefully draw a circle on the paper by outlining a coin or the cap of the hand sanitizer bottle. Make sure the line is continuous, thick and clear.
- Place a few drops of the hand sanitizer liquid or gel in the middle of the circle. Neither should you add too much of sanitizer that it overruns the line nor should it be too little that it doesn’t diffuse past the line.
- Let the hand sanitizer slowly diffuse and move out of the circle. The liquid sanitizer will diffuse almost instantly while the gel-based will take some time.
- You can also do repeat this with a little bit of water to see how a fake sanitizer without alcohol behaves.
If the sanitizer contains sufficient quantity of alcohol you will see that the line that you had drawn with the ballpoint pen will dissolve in the sanitizer and the colour starts to spread out. However if the sanitizer does not contain the required quantity of alcohol the line will not be dissolved and the sanitizer will just defuse past the line without any change.
This simple test is based on the principle of paper chromatography, The ink which is used in water resistant ballpoint pen does not dissolve in water but very quickly dissolves in alcohol. This causes the ink to move along the front of the diffusing sanitizer and spreading out. If the alcohol content is less the solubility of the ink is not sufficient and the line doesn’t move.
The Wheat Flour Dough Test for Hand Sanitizer
- Take one tablespoon of wheat flour on a plate. You can also take maize or other flr that quickly forms a dough with water.
- Add one tablespoon of the sanitizer you want to test. Do not add too much of the sanitizer as even real sanitizer contains 30% water which can make the dough if you add too much to the flour.
- Knead the flour and the sanitizer together to make a dough.
- If the sanitizer contains an excess amount of water the flour will quickly become sticky and eventually turn into a dough.
- If it contains the right amount of alcohol the flur will not become sticky and stay like a powder and eventually the sanitizer will dry up leaving behind the flour.
This test is based on the simple fact that flour needs water for the gluten and carbohydrates to swell and become sticky and turn into dough. Alcohol on the other hand competes with the gluten and carbohydrates for the water molecules and won’t let them hydrate and become sticky. This test is very sensitive and can easily detect samples with 60% or less of alcohol.
The Hair Dryer test for Hand Sanitizer
- Take one tablespoon of the sanitizer in a small bowl.
- In another bowl take some water
- Using a hair dryer dry the sanitizer for 30 seconds. Make sure to let the hair dryer heat up before you start.
- In the same way and at the same temperature dry the water.
- If the sanitizer has the required amount of alcohol it will dry up significantly compared to the water.
This test is based on the principle that alcohol has a much lower boiling (78 C) point compared to water (100 C).