QOTD 79: Insect repellents with 20% vs 40% DEET are equally effective. Find out why!!

DEET (aka. Diethyltoluamide) is a widely used ingredient in insect repellents. What does the concentration of DEET in insect repellents determine? *

Choose from one of the following

The strength of the insect repellent

The duration of protection of the insect repellent

The shelf life of the insect repellent

Answer: The duration of protection of the insect repellent

Further explanation along with participant’s submissions will be available here at 10pm Standard Melbourne Time. Thank you for your participation and feel free to make use of the comments section to ask questions or share useful insights that is relevant to this post.

Created by KW

Participants' Submissions

Answer: The duration of protection of the insect repellent

Ingredients

• Diethyltoluamide (DEET): Active ingredient
• N-Octyl bicycloheptene dicarboximide: Enhances the effectiveness of insect repellents
• Di-N-Propyl Isocinchomeronate: Fly repellent

Extra Information^{1, 2}

• The concentration of DEET in a product indicates how long the product will be effective. A higher concentration does not mean that the product will work better; It means that it will be effective for a longer period of time
• DEET concentrations over 50% provide no added protection
• High DEET concentrations can lead to side effects e.g. skin rashes, skin irritation, and blisters
• DEET may be used on adults, children, and infants older than 2 months of age
• To apply to face, first spray product onto hands, then rub onto face
• Use just enough repellent to cover exposed skin and/or clothing. Avoid over-application of the product
• Generally, repellent with DEET should not be applied more than once a day
• Use only when outdoors and wash skin with soap and water after coming indoors
• Avoid using a single product containing DEET and sunscreen because sunscreen needs to be reapplied frequently, while DEET should not be applied more than once a day

References

1. CDC (2018). Fight the Bite for Protection from Malaria Guidelines for DEET Insect Repellent Use. [online] Cdc.gov. Available at: https://www.cdc.gov/malaria/toolkit/DEET.pdf [Accessed 10 Nov. 2018].
2. KidsHealth (2018). Are Insect Repellents With DEET Safe for Kids?. [online] Kidshealth.org. Available at: https://kidshealth.org/en/parents/repellent.html [Accessed 10 Nov. 2018].