Is It Safe to Use Mosquito Repellents All Night? Doctors Warn of Health Risks in Closed Rooms

Mosquito repellents are a common household item in India, especially during the warmer months when diseases like dengue and malaria are a major concern. While they do protect against mosquito bites, doctors warn that using them all night—especially in closed, poorly ventilated rooms—can have serious health risks.

What’s Inside Mosquito Repellents?

Most commercial mosquito repellents use synthetic chemicals that either repel or kill mosquitoes. Two common ingredients are:

• Allethrin: A synthetic version of pyrethrins (naturally found in chrysanthemum flowers), commonly used in coils and vaporizers. While effective, prolonged exposure—especially in small or closed rooms—can cause headaches, throat irritation, eye discomfort, or even breathing issues.
• DEET (N,N-diethyl-meta-toluamide): Found in creams, sprays, and roll-ons. DEET is powerful but should be used cautiously. High concentrations can irritate skin and aren’t recommended for babies under two months. For children, only use repellents with up to 30% DEET, as advised by the American Academy of Pediatrics.

Are Creams and Roll-ons Safer?

Creams and roll-ons offer direct protection and may seem like a safer choice, but regular use can still cause skin irritation, allergic reactions, or long-term effects—especially for people with sensitive skin or allergies.

The Health Risks of Overnight Use

Doctors strongly caution against using mosquito coils and vaporizers overnight in closed spaces. The fumes from coils, in particular, are harmful when inhaled for long periods. In fact, one mosquito coil can release as much smoke as dozens of cigarettes, increasing the risk of headaches, throat irritation, coughing, and worsening of asthma or other respiratory conditions.

Safe Use Tips

To reduce health risks, follow these precautions:

• Keep coils or vaporizers 2–3 meters away from the bed.
• Avoid placing them above or next to your pillow.
• Keep a window slightly open to allow for better air circulation.
• Turn off the repellent after a few hours if possible, once mosquitoes are cleared.

Safer Alternatives to Chemical Repellents

Looking to avoid chemical exposure altogether? Try these safer options:

• Mosquito nets: A reliable, chemical-free barrier.
• Natural repellents: Oils like citronella, neem, or eucalyptus can be effective and gentler on the body.
• Electric mosquito zappers: These kill mosquitoes using light without releasing any fumes.