Toxic candles are made from paraffin wax, synthetic
fragrance and metal wicks with lead. Scented paraffin candles release a large
number of chemicals into the air both before lighting and when lit. And some of
these chemicals are toxic.
The smoke emitted by paraffin wax contains carcinogens like acetaldehyde, formaldehyde, acrolein, phenol, benzene, toluene, xylene and unburned/partially burned hydrocarbons like polycyclic aromatic hydrocarbons (PAH) which are well known for their cancer-causing potency.
Burning candles can also release nanosize particles and soot into your air. Sooting occurs when combustion conditions are impaired when burning candles. Scented candles and are more likely to produce soot than unscented candles.
Also, candles in glass containers produce more soot because the container causes unsteady air flow and disturbs the flame shape.
Non Toxic candles are made of beeswax, soy or coconut wax. They should be unscented with cotton or paper wicks.
If you can’t live without scented candles, choose ones made with essential oils. Keep in mind that essential oils will emit chemicals into your air. And burning even non toxic candles may emit soot and particles.
To reduce soot and particles, avoid glass containers, keep candles away from drafts, and extinguish candles by cutting the wick.