New Danish Research on Fine Particles from Candles Supports Candle Safety

Numerous media reports in past years claim that candles are a main source of fine particulate indoor air pollution and therefore present a health risk. New research from the Danish Environmental Protection Agency, Miljøstyrelsen refutes this.

The study's main objective was to scientifically determine the number and composition of particles and other substances emitted by candles during normal use. The study tested popular candles in Denmark and made the following conclusions: 

  • Candles do indeed emit a comparably high number of fine particles during burning. But as long as the candles are protected from drafts as instructed by the manufacturers, virtually all particles emitted by most candles consist of the salts used to treat the candle wicks. These salts dissolve easily in water, i.e., they are not persistent and can be excreted easily by the body.
  • The soot content of the particles is very low and much lower than in diesel exhaust for example.
  • Heavy metals, such as lead or nickel for example, could not be detected in the emissions.
  • The emission of volatile organic compounds (VOCs) was unremarkable and at very low levels.
  • Due to these significant differences, particles emitted by candles cannot be compared directly with those emitted by other sources, e.g., by car traffic.
  • It is recommended to purchase high-quality candles, protect them from drafts during burning and to trim the wick. 

Obtained from the National Candle Association.

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