Chemicals that kill or slow the growth of germs

Key points about antiseptics

  • Antiseptics are chemicals that kill or slow the growth of germs or micro-organisms (bacteria, fungi and viruses).
  • They may be applied on different parts of your body such as on your skin and in your mouth and throat.
  • Find out how to use them safely.
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Antiseptics are not the same as disinfectants
Antiseptics are commonly used on the skin (as creams, medicated soaps, medicated powders)  or and in your mouth and throat (as gargles, sprays and lozenges). They are in such a low strength that they don't cause harm to your skin or body when used as directed. They do not treat infections – these need to be treated with antibiotics, antivirals or antifungals.

Disinfectants are strong chemicals that are used to clean surfaces where germs thrive and multiply, such as door handles, floors or bathrooms. Disinfectants are harmful to your body and should never be applied on human skin or ingested (swallowed or taken into your body in any way). Read more about disinfectants.

Antiseptics for the skin come as creams, ointments, solutions, medicated powders and medicated soaps. They may be put on:

  • some types of burns, to lessen the chance of infection
  • your skin before surgery, to reduce bacteria on the skin near the operation site. 

Antiseptics are also added to some hand cleansers, but plain soap is just as effective. Antiseptic hand sanitisers are useful when it is not possible to wash your hands using soap and water (the best way to clean your hands). Read more about hand washing.

Antiseptics are not very useful for minor skin infections, cuts and grazes. Cuts and grazes are best treated by cleaning the area with warm water and covering it with a clean plaster or bandage. Covering the wound prevents infections. There is no need to use an antiseptic as it may damage your skin and slow healing. Read more about cuts and grazes.

Do not use antiseptics:

  • to treat sunburn 
  • on wounds with particles that won’t wash away
  • on wounds caused by human or animal bites
  • on an eye injury.
Examples of antiseptics used on the skin
  • Hydrogen peroxide (Crystacide®, Crystaderm®)
  • Povidone iodine (Betadine®)
  • Chlorhexidine salts (Savlon®, Medipulv®)
  • Bepanthen First Aid®
  • Potassium permanganate (these may come as tablets but must not be swallowed)

Some antiseptics are quite strong and should be diluted before you use them on your skin. If used undiluted, they may cause chemical burns or severe skin irritation. Check with your pharmacist if the antiseptic you are using needs to be diluted. 

Do not use antiseptics for more than 1 week. If the affected area has not healed or improved, see your doctor.  

Antiseptics that are applied to your skin are mostly safe. However, sometimes they can cause irritation and allergic reactions. There have been reports of severe allergic reactions, including anaphylaxis from chlorhexidine. If you notice a rash or your skin becomes itchy and red, stop using the antiseptic and contact your pharmacist or doctor.

Yes, it is safe to use diluted bleach on your skin. Adding household bleach to your bath or tub with warm water is used as an antiseptic to decrease bacteria (bugs) on your skin. This can help improve eczema and prevent skin infections. This is commonly called bleach baths and it’s used no more than twice a week. If you have eczema and your doctor has recommended bleach baths, then they may be used but follow the instructions carefully.

Bleaches come in different strengths. When preparing a bleach bath, it is very important that the bleach is diluted in the correct amount of water. Do not apply undiluted bleach directly to the skin. This can cause severe burns and is very harmful. Household bleach comes in different strengths, Here is guidance on how to prepare a bleach bath(external link).

Make sure you keep the bleach in the original container in a safe place, out of reach and sight of children.

Antiseptic gargles are used for mild infections of your mouth and gums. Sometimes an antiseptic gargle may be used to rinse your mouth, instead of cleaning with a toothbrush, if brushing is painful or not possible.

Antiseptic lozenges and throat sprays are available to relieve a sore throat, but they may not be of benefit, and they can cause a sore tongue and sore lips. 

Examples of antiseptics used in the mouth and throat
  • Cepacol®
  • Savacol®
  • Rivacol® 
  • Thymol glycerine®
  • Listerine®
  • Difflam-C®

Using antiseptic gargles safely

When using antiseptics to rinse your mouth or gargle, it is important to spit it out – try not to swallow after use. Some antiseptic gargles need to be diluted with water before use and others can be used without diluting them. Always read the instructions on the package or check with your pharmacist about how to use your gargle.

Ask your pharmacist about:

  • whether your gargle or mouthwash needs to be diluted or not
  • how much liquid to gargle with
  • how many times a day you need to use the gargle or mouthwash.

For example, when using Savacol mouthwash, you must dilute 10–15 mL of mouthwash with 10–15 mL of warm water, then rinse your mouth or gargle for 1–2 minutes, then spit it out – try not to swallow. You can use the gargle up to 3 times daily after meals.


Bleach bath instructions

Starship, NZ, 2023

5 questions to ask about your medications

5 questions to ask about your medications

Health Quality and Safety Commission, NZ, 2019

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

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