The chemical hydrogen peroxide is a common ingredient in many bleaches, dyes, cleansers, antiseptics, and disinfectants. This versatile liquid has many potential uses but also several safety concerns if people use it incorrectly.

Due to its availability and antiseptic properties, many people consider hydrogen peroxide a staple in their medicine cabinet and first aid kit.

Hydrogen peroxide may come in different strengths, or concentrations, depending on the intended use. Some common concentrations include:

  • 3%, the typical concentration for household products
  • 6–10%, the concentration in some hair dyes and teeth whitening products
  • 35%, the concentration of food-grade hydrogen peroxide — which, despite its name, a person should never consume
  • up to 90%, the concentration in industrial products not intended for home use

While a person may safely use weaker concentrations of hydrogen peroxide, it can still cause internal and external irritation and other complications. The risk of using hydrogen peroxide increases with higher concentrations, according to the Agency for Toxic Substances and Disease Registry (ATSDR).

This article discusses what hydrogen peroxide is and how a person can safely use it, as well as its risks and when to contact a doctor. The article also offers suggestions for alternatives products to hydrogen peroxide.

A person applying hydrogen peroxide to a wound.Share on Pinterest
Robert Przybysz/Shutterstock

Hydrogen peroxide (H2O2) is colorless liquid with a similar chemical formula to water (H2O). The extra oxygen molecule — from which hydrogen peroxide gets its name, as it features one hydrogen per oxygen — represents the main difference between the formulas.

This extra oxygen molecule allows hydrogen peroxide to act as a powerful oxidizing agent. This means it can accept electrons from other substances. This makes it a powerful disinfectant — it can oxidize the cell membrane of a microorganism, which results in a loss of structure and leads to the death of the pathogen.

Even though many people view hydrogen peroxide as a safe general disinfectant, the ATSDR notes that exposure can cause irritation of the:

  • eyes
  • throat
  • respiratory airway
  • skin

Drinking hydrogen peroxide may also result in severe gastrointestinal effects.

Due to its oxidizing properties, hydrogen peroxide acts as an effective disinfectant. People can use commercially available 3% hydrogen peroxide to disinfectant surfaces.

According to the Environmental Protection Agency, evidence also indicates that hydrogen peroxide works as an effective disinfectant against SARS-CoV-2, the virus that causes COVID-19.

While experts do not necessarily recommend this application, hydrogen peroxide can also act as an effective wound cleanser, particularly as it can help remove debris from the wound.

A person can generally use hydrogen peroxide safely as a mouth rinse as long as they use it correctly. It may cause harm if a person uses it too often or if the concentration is too strong.

A 2017 randomized controlled trial suggests hydrogen peroxide may help treat gum disease. It may also be beneficial for canker sores, according to University of Florida Health.

However, people should not use too strong a concentration, such as 35% food-grade hydrogen peroxide. If a person accidentally swallows this, it could lead to serious gastrointestinal problems.

Experts also advise that people to apply caution when mixing the solution or spitting it out to avoid inhalation or getting it in their eyes.

An individual may also consider using hydrogen peroxide to whiten their teeth. Many commercial teeth whitening solutions contain hydrogen peroxide as an ingredient, and a 2014 study suggests that products containing hydrogen peroxide may lighten tooth enamel.

However, a 2016 study suggests it may adversely affect tooth enamel. So, people should avoid leaving hydrogen peroxide solutions on their teeth for extended periods

While some people may still use hydrogen peroxide to clean wounds, experts recommend against this. It can irritate or damage the cells necessary for wound healing.

Due to its disinfecting and bleaching properties, some people may consider using hydrogen peroxide as part of their skin care routine.

However, to achieve these effects, people would likely need to use higher than the 3% concentration deemed safe in household products. At higher concentrations, the risk of severe burns and blistering greatly outweighs any potential skin benefit.

For example, people may use hydrogen peroxide to treat acne.

Some research, such as a 2016 randomized controlled trial, suggests it may have comparable results as other acne treatments. However, due to its potential to irritate the skin, people should use other acne treatments instead.

The medical term for earwax is “cerumen.” Hydrogen peroxide is a cerumenolytic, meaning it can dissolve earwax. For this reason, many ear drops contain hydrogen peroxide as a common ingredient to remove earwax.

However, people should apply caution when using hydrogen peroxide in their ear. According to a 2019 case study, side effects may include:

  • temporary loss of hearing
  • increased pain in the ear
  • ringing of the ears
  • temporary bubbling sensation
  • dizziness

People should avoid using a strong concentration of hydrogen peroxide or using it too frequently. This can irritate the ear and result in complications.

In addition, a person should not use ear drops if they have an ear infection or a damaged eardrum.

While household 3% hydrogen peroxide is generally safe, exposure to higher concentrations can come with risks.

Some marketers may promote stronger concentrations of hydrogen peroxide as an alternative treatment for various treatments. However, typically no scientific evidence supports such claims, which can result in severe injury or potentially life threatening situations, according to Poison Control.

People should still apply caution when using 3% hydrogen peroxide. It can be toxic if a person ingests, inhales, or gets it on their skin or in their eyes.

According to the ATSDR, complications may include:

  • vomiting
  • gastrointestinal irritation
  • gastric distention
  • gastric embolism
  • respiratory paralysis
  • pulmonary irritation
  • ocular irritation
  • pain
  • burns and blistering

If people wish to use alternative products to hydrogen peroxide, they can consider the following:

Wound cleaning

A 2019 study suggests that people can clean wounds with sterile water, such as bottled drinking water or water from a shower. A combination of clean water, ointments, and clean dressing usually suffices to allow most wounds to heal well.

Acne

Benzyl peroxide is an over-the-counter (OTC) product the Food and Drug Administration (FDA) has approved for acne treatment.

It has antibacterial properties, meaning it may act effectively against bacteria that can lead to acne. It can also reduce sebum, an oily substance that can result in acne.

Earwax

A 2020 study notes that a person can often use a soft washcloth to gently remove wax that comes out of the ear after showering. Other methods for safely removing earwax may include:

  • a rubber ball syringe
  • certain oils or glycerin
  • an OTC ear drop

Exposure to hydrogen peroxide may produce mild symptoms. However, whenever doubt exists about whether these symptoms warrant medical attention, an individual should call a healthcare professional.

They also should report to the doctor any symptoms of an allergic reaction, such as rash and itching.

If any symptoms seem serious, a person should go to the emergency room immediately. For example, according to Poison Control, life threatening symptoms of a gas embolism include:

  • chest pain
  • difficulty breathing
  • confusion

Hydrogen peroxide, a versatile and readily available chemical, is a common ingredient in many disinfectant and cleaning products, due to its properties as a powerful oxidizing agent.

While it may have a variety of potential uses, a person should generally use it only as a disinfectant and should use products containing a safe amount of hydrogen peroxide. An individual may also consider safer alternatives to use.

People should try to avoid exposure to strong concentrations of hydrogen peroxide. When using a 3% or lower concentration, they should ensure they do not ingest, inhale, or get the liquid on their skin or in their eyes.

If this does occur, it may result in adverse events, such as irritations of the lungs, stomach, skin, or eyes. If a person experiences any concerning symptoms, they should call a healthcare professional or visit an emergency room.