Treading Lightly

is a regular column, written by Meg Murray-Bradshaw, and appears in our Nature Matters quarterly newsletter.

Winter, 2010: Healthy Candlelight

What could be better than candles burning on a cold winter’s night? I invite you to indulge yourself with soy or beeswax candles. But for indoor air quality, I suggest you avoid the easier-to-find paraffin variety. 

Fine Particulate Matter:

Fine particulate matter (PM) is a mixture of solid particles and liquid droplets in the air which are small enough to penetrate the respiratory system further than larger particles. Fuel combustion, including candle-burning, can create fine PM. The US EPA explains that a well-designed and maintained candle emits negligible fine PM because almost all the particles are consumed by the flame. But poor candle composition and design, wick length or drafty air can lead to smoldering, which can create PM beyond ambient air quality standards. In addition, blowing out candles can instantly create a large amount of PM. The EPA recommends extinguishing the flame with a wet cloth, scissors or a snuffer. 

Polycyclic aromatic hydrocarbons:

Polycyclic aromatic hydrocarbons (PHAs) are products of incomplete combustion. Indoor sources include candles and incense. A study by the Centers for Children’s Environmental Health and Disease Prevention Research found that five-year old children exposed to high levels of PHAs scored 4 points lower on standardized intelligence tests than less exposed children. 

Paraffin vs Soy or Beeswax:

Research at South Carolina State University in 2009 compared emissions from paraffin wax and soy candles, all of which were non-scented, non-pigmented and contained no dyes. Researchers explained that paraffin candles produced significantly more soot than others, and found that paraffin candles emitted sharp peaks of hazardous chemicals such as benzene and toluene. Soy and beeswax candles did not emit significant levels of these chemicals. 

Shopping:

Soy candles are easier to find these days, including at stores such as Target. Beeswax candles require a little more effort to find, but there are plenty of online sources. While beeswax candles tend to cost more than others, they burn much longer. And they emit a natural, warm honey smell. So, enjoy soy or beeswax candlelight tonight!