How to distinguish 75% alcohol from 95% alcohol What is the difference between 75% alcohol and 95% alcohol

Alcohol is a common disinfectant. It can kill viruses and bacteria and has a good disinfecting effect. Many people use alcohol for disinfection. There are 75% alcohol and 95% alcohol. So what is the difference between 75% alcohol and 95% alcohol? Let's take a closer look!

What is the difference between 75% alcohol and 95% alcohol?

Different sterilization effects

If used for disinfection, 70% to 75% is usually used. This is because too high a concentration of alcohol will form a protective film on the surface of the bacteria, preventing it from entering the bacteria, making it difficult to kill the bacteria completely. Therefore, 95-degree alcohol is generally not used for disinfection.

If the alcohol concentration is too low, although it can enter the bacteria, it cannot coagulate the protein in its body, nor can it completely kill the bacteria. Among them, 75% alcohol has the best disinfection effect.

Different uses

75% alcohol can be used for skin disinfection and thermometer disinfection, such as disinfection before injection or disinfection of the skin around wounds.

95% alcohol is used to wipe ultraviolet lamps. This alcohol is commonly used in hospitals, but in families it is only used to clean camera lenses.

In addition, 95% of alcohol is also used as fuel. For example, scientific research departments and medical units need to use this concentrated alcohol as alcohol stove, alcohol lamp fuel, and heating related chemical reagents for scientific research. It can also use alcohol flames to disinfect the surface of small medical equipment.

How to distinguish 75% alcohol from 95% alcohol

75% alcohol is medical ethanol, which is also known as medical alcohol. 95% alcohol is not ethanol but methanol. Methanol and ethanol are very different! Methanol not only cannot have the same disinfecting effect as ethanol, but also methanol is toxic! The way to distinguish 75% alcohol from 95% alcohol is to smell it. Methanol does not have the smell of alcohol!

Methanol and ethanol are two completely different substances. The molecular formula of methanol is CH3OH, which is a highly toxic chemical raw material. The molecular formula of ethanol is CH3CH2OH, commonly known as alcohol, which has one more methyl group than methanol. Experts say: "Methanol has a wide range of uses and is a basic organic chemical raw material and high-quality fuel. But methanol must not be used instead of alcohol for disinfection."

If you accidentally use 95% methanol alcohol, it will be ingested into the body through the respiratory tract and skin, and then become toxic. Short-term large-scale inhalation may cause mild eye and upper respiratory tract irritation symptoms. After a period of incubation, headaches, dizziness, fatigue, vertigo, drunkenness, confusion, delirium, and even coma may occur. Severe optic nerve and retinal damage may cause blindness! !

So when you buy alcohol, you must keep your eyes open and don't buy the wrong one. Using the wrong alcohol can be harmful to your body. If you accidentally use 95-degree alcohol and feel uncomfortable, you must go to the hospital for treatment in time!

Which one is better for disinfection, 75% alcohol or 95% alcohol

Studies have confirmed that 75% alcohol can have both protein coagulation and penetration effects, achieving a thorough sterilization function.

75% alcohol is suitable for disinfecting intact skin without wounds. For example, before giving an injection in the hospital, the nurse will always wipe the injection site with a cotton ball dipped in 75% alcohol. However, for skin with wounds, do not use 75% alcohol for disinfection, as it will cause a strong stinging sensation and will also affect the healing of the wound. It is recommended to use betadine or iodine tincture for disinfection.

95% medicinal alcohol is usually used to prepare Chinese medicine, or to make dishwashing liquid and cleaning agent. It can also be diluted to 75% alcohol for sterilization and disinfection. It can be diluted with distilled water or boiled tap water as needed, with a ratio of 3 parts 95% alcohol to 1 part water. When you dilute alcohol at home, as long as the final concentration is between 70% and 78%, you can achieve a 99% sterilization effect. It is not necessary to dilute it to a very high concentration to have a sterilization effect.

How much water to dilute 95% alcohol to 75%

About 27ml, it is best to dilute with distilled water, if not available you can also use boiled water.

The volume of water that needs to be added is 95/75-1=0.27 times of 95% alcohol. For example, the volume of water that needs to be added to 100 ml of 95% alcohol to make 75% alcohol is: 100×(95/75-1)=27 ml. If it is used for human body disinfection, it is best to use distilled water. In the absence of distilled water, it is also acceptable to use boiled water for emergency.

95% alcohol is mostly used as fuel. Medical units often need to use alcohol lamps and alcohol stoves, which are used to heat the preparation of test reagents or pharmaceutical preparations after being ignited. The flame can also be used to temporarily disinfect small medical equipment.