The Dark Side of Candles - Part One of a 2-part Report

I'm willing to bet there is hardly a household in America that doesn't contain at least one candle. Even Great-Grandma is likely to have a supply of utilitarian white emergency candles in her kitchen drawer. More than likely she also has a decent supply of lovely scented ones from Bath & Body Works, Home Interiors or at least Wal-Mart, thank you. They've been used from time eternal to light the darkness, and as an essential part of religious and secular ceremonies, birthdays, and prayer. Candles have exploded in popularity over the last several years. You can't beat them for "setting a mood." It's enticing to light a few around the room at the end hectic day, put one's feet up, and let them soothe our frazzled nerves.

In this first of a 2-part article, we'll explore how certain candles are a potential source of damage to the interior of homes in the form of black soot. Recent reports tell of damage to household interiors including walls, drapes, furniture and air conditioning equipment, oftentimes totaling in the thousands of dollars.

Getting that nice potent scent requires the addition of oil into the wax. The more oil added, the stronger the scent. But the addition of that oil can compromise the "clean" burning of the candles, and cause the excessive soot production. Candles also need the right amount of wax, air and wick to burn cleanly, so as not create any significant soot. Black soot residue is most noticeable inside glass jar candles. As the candle burns down deeper into the container, it can't get the proper amount of air it needs to maintain a clean flame, and a black ring is left behind.

David Krause is a Florida air quality manager who wrote a recent article for the RSES Journal, the official publication of the Refrigeration Service Engineers Society ( According to Krause, while carbon soot can have several potential sources in a residential setting besides candles, including fireplaces and natural gas stoves, these are either vented or carefully controlled to ensure a clean burn. In interviews with over 50 homeowners who have had problems with black soot deposits, he says "it became evident that candles are a common source of soot".

Krause reports that when the soot particles become air borne they collide and grow in size. They then become heavy enough to deposit due to gravity. He further explains that smaller airborne particles are minute enough is size to penetrate most air filters and migrate through a home's air conditioning system, blowing out of the supply vents. They often become electrostatically charged as a result, and are attracted to surfaces with a corresponding opposite charge, such as plastic surfaces. Plastic garbage cans, and the surfaces near the cans, for example, are prime attraction points for candle soot, as are the plastic surfaces of medicine cabinets. While very weak, this charge is sufficient to attract soot particles, according to Krause.

It doesn't stop there. Joe Frey, writing for, says once the candle soot settles, cleaning it off your walls, carpet, couch, and appliances can become impossible. You may have little choice but to replace the spoiled surfaces and items.

Mr. Frey also shares the account of Georgia contractor Chris Cole, whose client blamed extensive soot damage on an improperly installed heating system. Cole's insurance company paid for the woman's damage and Cole replaced the heating system and refinished the walls and ceilings. Two weeks after Cole's company replaced the customer's heating system, the walls were again covered in soot, and that's when Cole was able to attribute the damage to candle soot. In addition to burning numerous candles, she was also burning potpourri and incense. This woman "was just begging for problems".

This recent phenomena presents a dilemma with insurance companies, as this is relatively new territory not dealt with extensively in the past. Frey explains that insurers may or may not pay based on a policy's "named peril" provisions. That's the portion of a policy that spells out in clear terms what is and is not covered. Homeowner's policies also have what's called "sudden and accidental occurrence" provisions, which separates harmful events that happen overnight from those that develop over time.

So does all this mean we pitch out our coveted candle collections? Probably not. The amount of soot produced can be affected by wax and wick type, the quantity burned at any one time, and the length of burning time. In the meantime, here's a list of candle types to avoid from Mr. Krause to help candle lovers reduce that nasty black soot:

On the proactive side, there are ways to assure the cleaner burning of candles:

While physical damage to a home can be devastating, even more sinister may be the effect on our health. We'll explore that aspect of this "burning" issue next month.

- The Staff at Filter Solutions