New Delhi, Feb. 23 -- Aroma compounds released from the scented wax melts can react with ozone in indoor air to form potentially toxic particles, researchers have warned.

The study challenges the perception that scented wax melts are a safer alternative to combustion-based candles.

Previous research has shown that scented wax melts emit more airborne scent compounds than traditional candles.

The direct heating of the wax maximises its surface area, thereby releasing more fragrance - such as volatile organic compounds (VOCs) made of hydrocarbons - into the air, according to the study published in the ACS' Environmental Science & Technology Letters.

Researchers know that these chemicals can react with other compounds in the air to form ...