Table of Contents


The Soaps and Experiment Process

The Problem and Hypothesis


The Conclusion

The Application

Photo Gallery





© 2010 Conary Coyne and Brandon Rocco

The Experimental Process

Materials Needed:

The materials needed for this project include hand sanitizer, Ivory soap, bar soap, antibacterial liquid soap, a black light, camera, stopwatch, Handi-Glo® lotion that acts as remaining dirt and glows under the black light. The Lotion looks and feels like moisturizer or a hand cream, but it has a special ingredient that glows a whitish-blue under the ultra-violet rays of the black light. So, if you apply this lotion to your hands and try to wash it off, you can see where you did not wash when you put your hands under the Ultra Violet light.

Experiment Step by Step Process:

Step 1: Collect all materials needed for experiment (Hand sanitizer, Ivory soap, bar soap, liquid soap, black light, camera, stopwatch, and lotion that acts as remaining dirt and glows under the black light.

Step 2: Gather all possible information about each soap and hand sanitizer, i.e. ingredients, or which one has worked best in other studies, so we can create a hypothesis and prediction about the experiment.

Step 3: We will test multiple subjects, each subject will be required to wash their hands for 1½ minutes with the four different types of soap. They will stop every fifteen seconds, and we will take a photo of their hand under the black light, with the lotion on. The glowing spots will show where they did not wash well. In total we will have taken 24 photos of each subject’s hands under a black light.

Step 4: We will analyze each photo, then estimate what percentage  of the hand and wrist surface area is still glowing, or covered in dirt. We will graph the results and draw up a conclusion based on the results of the experiment.

Soaps Used

Ivory Soap:

Ivory soap is a light, flakey type of bar soap made with Sodium tallowate, sodium cocoate or sodium palm kernelate, water, sodium chloride, sodium silicate, magnesium sulfate, and fragrance. Classic Ivory Soap is a simple, pure formula that cleanses your skin by removing dirt and oils which can clog pores. The classic, 99 44/100% pure formula contains no heavy perfumes or lotions so it leaves your skin feeling naturally clean with a light, Ivory-clean smell. Ivory has been the leading pure soap on the market for decades.

Bar Soap:

There are either three or four basic ingredients in soap, plus or minus the essential oils, perfume and dyes. The first main ingredient in soap is fat or oil. Oils and fats contain acids. Solid fats like coconut oil, palm oil, tallow (rendered beef fat), or lard (rendered pork fat), are used to form bars of soap that stay hard and resist dissolving in the water left in the soap dish.  The next main ingredient is usually lye or potash. The final ingredient is optional, and it can be an emulsifier and/or natural skin-care ingredient that does not have an acidic base, such as aloe. Palmolive traditionally claimed to make its soap using palm and olive acidic-based fats. Bar soap rubs off the top layers of dirt from the cracks  and pores in your skin, but is ineffective with the deep layers of dirt. When washing with bar soap, you should wash for a longer amount of time than liquid soap, so the water and soap has enough time to wash every part of your hand.

Liquid Soap:

Antibacterial liquid soap is a form of liquid soap which includes ingredients which are designed to fight bacteria. The efficacy of the soap can vary, depending on the ingredients and how it is used, with some killing up to 99% of bacteria, while others tend to be less robust. People use antibacterial liquid soap on their hands and bodies because they are concerned about the spread of bacteria, or because they want to prevent bacterial infections. In the case of hand washing, the soap reduces the number of bacteria on the hands, making it difficult to spread bacteria through direct contact or the handling of shared objects like doorknobs. Through other test, it has been proven that liquid soap most effective because the liquid is easier to apply and use because liquid can run in between the pores and the ridges of the skin flushing out any of the dirt and germs on the hand while killing them effectively.

Hand Sanitizer:

A hand sanitizer is a supplement or alternative to hand washing with soap and water. Various preparations are available, including gel, foam, and liquid solutions. The active ingredient in hand sanitizers may be isopropanol, ethanol, or n-propanol. Inactive ingredients in alcohol rubs typically include a thickening agent such as polyacrylic acid for alcohol gels humectants such as glycerin for liquid rubs, propylene glycol, and essential oils of plants. Alcohol based hand sanitizers are more effective at killing germs than soaps and do not dry out hands as much as most soaps. Hand sanitizer works by killing cells—not human cells. It kills microbial cells. It’s based on the use of 70 per cent isopropanol alcohol, which is rubbing alcohol.  That’s the concentration of rubbing alcohol that is most effective in killing germs—it’s even more effective than 100 per cent. Because it has a little bit of water in it, it improves penetration. For a virus, sanitizers work by disrupting the virus’s outer coat. For a bacterium, they work by disrupting its cell membrane. However hand sanitizer doesn’t remove dirt, so even after you use it, at least 85% of your hand’s surface area will still be covered with dirt.