[ Back to main article ]

Avoiding mosquitoes and sunburn often go hand-in-hand. But so does improperly mixing sunscreen and DEET-based insect repellents, says a Canadian scientist.

"By using sunscreen and DEET together you can lose the protection they offer and increase your health risks," says Dr. Xiaochen Gu, a pharmacy researcher at the University of Manitoba.

His Canadian Institutes of Health Research-funded studies reveal that mixing sunscreen and insect repellent increases the amount and the rate at which the active chemicals in both products pass through skin into the body. DEET and sunscreen are designed to work on the skin surface. And Dr. Gu says there are concerns about the long-term health effects of DEET.

Here are Dr. Gu's top five tips for not getting bitten or burned when mixing sunscreen and DEET:

1. Avoid mixing DEET and sunscreen. Mixed together the active chemicals pass through the skin at least one-and-half times as fast. You lose their skin-surface protection. Apply DEET to clothing rather than on the skin.
2. Apply sunscreen first, then repellent. Sunscreen works best close to the skin, and blocks the action of DEET if applied on top of the repellent.
3. Choose liquid repellent instead of lotion. Lotion increases the amount of DEET absorbed by the skin.
4. Wash them off when you go inside. To avoid absorbing DEET and sunscreen, wash them off with soap and water.
5. Careful with kids and elderly. Seniors' older skin is more permeable to chemicals. To prevent ingesting it, kids shouldn't have DEET on hands or face.