Personal insect repellents

Personal insect repellents can be applied to the body in the form of an aerosol, lotion, gel or wipe, or worn as a wearable device such as a band, patch or sticker. Care must be taken when choosing a personal insect repellent, as product efficacy varies greatly. 

Based on rigorous scientific evidence, the Western Australia (WA) Department of Health (the Department) currently recommends personal repellents in the form of a lotion, spray or gel that contain either diethyltoluamide (DEET) or picaridin as an active constituent. It may be useful to refer to the review of recommendations on the safe and effective use of topical mosquito repellents (external) for further information on product efficacy. 

In Australia, it is a legal requirement for all insect repellents to be registered with the Australian Pesticides and Veterinary Medicines Authority (APVMA) (external). To ensure a repellent product is registered, check the product label for an APVMA approval number or search for the product in the Public Chemical Registration Information System (PubCRIS) database (external).  

Diethyltoluamide

DEET has been widely used in insect repellents since the 1950s and remains a safe, effective active constituent when used according to the label instructions. 

Which DEET concentration is suitable?

Current repellents on the market contain anywhere between >10% through to 80% DEET. It is a common misconception that the concentration of active constituent affects repellent efficacy. DEET concentration alters only the length of time in which the repellent works for, not its ability to repel mosquitoes. As such, it is important to choose a concentration that best suits the length of time you will be exposed to mosquitoes for. This information is generally found on the product label.

Products containing up to 20% DEET

As a guide, products containing <10% DEET provide approximately 2 hours of protection, whilst 20% DEET can last approximately 4-6 hours. Products containing up to 20% DEET are suitable for individuals wanting to prevent mosquito bites during peak periods of activity around dawn or dusk. If you are going to exceed the length of time the repellent provides protection for, always refer to the label instructions for specific information on reapplication times. 

Products containing >20 - 80% DEET

Products containing 40-80% DEET provide 8-12 hours of protection. Application of high concentration DEET products in adults should be limited to times when mosquito exposure is lengthy (eg. extended fishing/camping trips, defence force training exercises etc). Take care to reapply the product according to the label instructions as skin irritation may occur if reapplied too frequently. Do not use high concentration DEET products on children. 

Note, if you require prolonged protection but do not wish to use a high concentration DEET product, you can achieve the same level of protection by reapplying a lower concentration product according to the product label.

Picaridin

Picaridin was developed in the 1990s and remains widely used as an effective active constituent in personal insect repellents. Products containing picaridin vary in concentration from <10% to 20% and provide between 2-6 hours of protection. Always refer to the label for application instructions and reapplication guidelines.

Oil of lemon eucalyptus

More recently, repellent products containing p-menthane-3,8-diol (PMD), also known as oil of lemon eucalyptus (OLE), lemon eucalyptus oil (LEO) or extract of lemon eucalyptus, have been registered in Australia. Preliminary evidence suggests that products containing PMD may provide an effective alternative to DEET and picaridin, although some field trials overseas have shown variable protection against mosquitoes. To date, there have been no published studies conducted in WA to determine whether the active constituent is effective against local mosquito species. Whilst there has been one efficacy study conducted in Australia (external), the species included in the trial (Aedes aegypti and Anopheles farauiti ) are of little relevance to WA.

It is important not to confuse products containing PMD/OLE with eucalyptus-based essential oil formulations, as the latter do not generally provide long periods of protection.

'Natural' botanical extracts

The Department does not recommend the use of ‘natural’ personal insect repellents containing botanical extracts as they provide limited protection against mosquitoes. Those botanical extracts that do repel biting insects, only do so for a short duration (<30 min) (external), and must be reapplied at an impractical frequency to provide protection comparable to DEET or picaridin. These products should not be relied upon to provide adequate or prolonged protection in regions where mosquito-borne disease is a risk.

The APVMA has also reported a growing number of unregistered, natural repellents on the market (external). Always check that a product has an APVMA approval number, to ensure it is registered and meets Australian safety standards.

Wearable devices

Wearable repellent devices (wristbands, patches and stickers), impregnated with active constituents such as DEET or botanical extracts, are becoming increasingly popular. These products are not recommended as their efficacy is limited. Research demonstrates that wristbands impregnated with botanical extracts fail to repel mosquitoes (external), whilst those impregnated with DEET only limit mosquito exposure around the device itself and do not protect exposed skin elsewhere on the body. Individuals should not rely on these products to provide adequate protection in regions where mosquito-borne disease is a risk.

General repellent application guidelines

It is important to apply a repellent containing DEET or picaridin appropriately, for it to be effective. The following guidelines will assist you in this process: 

  • Always apply the repellent according to the instructions on the label.
  • Apply repellent to all areas of exposed skin. Repellents will not work if you apply them sparingly.
  • For all areas (except face), apply repellent directly to skin and spread evenly with hands.
  • For face application, apply first to hands and then spread evenly on face, avoiding the mouth and eyes.
  • Do not apply repellent under clothing.
  • Choose a repellent concentration that best suits the length of time you will be exposed to mosquitoes. 
  • For prolonged periods outdoors, you may need to reapply repellent. Follow label instructions about how often you need to do this.
Repellent application in children

Where possible, avoid exposing your baby or child to mosquitoes. If in a mosquito-risk area, keep children inside at peak times of mosquito activity, dress them in long, loose-fitting protective clothing (including socks/shoes) and use a bed or pram net if appropriate.

If mosquito exposure is unavoidable and children cannot be protected through the above measures, refer to the following repellent application guidelines: 

  • Under 12 months – repellents containing DEET or picaridin are not recommended.
  • From 12 months – repellents containing up to 10% DEET or picaridin can be used.

When applying an insect repellent to a child, safety and efficacy can be maximised by following these guidelines:

  • Always apply the repellent according to the instructions on the label.
  • Do not allow children to apply repellent.
  • Apply repellent first to the hands of the carer and then spread evenly to exposed skin of child.
  • Avoid applying repellent to the child’s hands or feet, near the eyes or mouth.
  • Avoid applying repellent under clothing.
  • Rinse repellent off once mosquito exposure is no longer an issue. 
  • Wash any clothing that may have been exposed to the product.

Repellents are considered safe when applied correctly. However, if you experience a serious reaction, consult your GP or call the Poison Information Centre Australia on 13 11 26.

More information

• Medical Entomology
Phone: (08) 9285 5500 
Medical.entomology@health.wa.gov.au
Last reviewed: 17-02-2020