Assessment of Modeled Indoor Air Concentrations of Particulate Matter, Gaseous Pollutants, and Volatile Organic Compounds Emitted from Candles

ABSTRACT

Candle burning is regarded as an important source of airborne pollutants in indoor environments. Indoor concentrations of aldehydes, benzo(a)pyrene, sulphur dioxide (SO₂), nitrogen oxides (NO_x), and particulate matter (PM) produced from the burning of scented candles and raw materials with different melting point/oil content (50/1, 55/9, and 65/6) were predicted using a single compartment mass balance model and compared to regulatory or guideline limits. Scented candles may be responsible for indoor acrolein concentrations that could become relevant to health only in the case of chronic exposure. Indoor concentrations of fine PM and SO₂ emitted from 65/6 wax burning under worst-case environmental and behavioral conditions were greater than their respective acute guideline limits. However, other waxes had levels of PM and SO₂ well below the recommended values. Indoor concentrations of nitrogen dioxide emitted from raw wax burning should be further investigated. The degree of pureness of raw waxes significantly affected the predicted indoor concentrations of PM and SO₂. In particular, 65/6 wax was criticized for its high content of impurities.

Key Words:

• scented candles
• paraffin waxes
• risk assessment
• risk management
• mass balance modeling
• SO₂
• NO₂

ACKNOWLEDGMENTS

We thank anonymous reviewers for comments on earlier drafts of this article. The present work was funded by Associazione Cerai d’Italia and Cereria Lumen S.r.l.