Soy wax is made from soybeans, while paraffin wax is made from petroleum (yes, the same petroleum used to make oil and gas). Discovered in 1850, paraffin wax is made by removing the waxy substance from crude oil. Soy wax was discovered in 1991 as an alternative to paraffin wax and is a hydrogenated form of soybean oil. Not only is soy wax all natural, it’s also sustainable since we can grow more soybeans. Paraffin wax is not sustainable because fossil fuels cannot be renewed.

All candles emit some amount of soot, but given the same conditions (length of the wick, presence of a draft, etc.), a paraffin candle will emit more soot than a soy candle. This soot can discolor the candle container and sometimes get on your walls, furniture and curtains as well, especially if you have a lot of air circulation that moves the soot around. If you light a soy candle and a paraffin candle next to each other, you’ll notice the difference in the soot.

Soot isn’t the only thing that paraffin wax emits. Burning or melting paraffin wax releases 11 known toxins—two of which are carcinogens—into the air. (A carcinogen is any substance or agent that promotes cancer.) Because soy wax is a biodegradable wax made from soybeans,  which we eat, it does not contain these toxins and carcinogens. Not only is soy wax better for the environment, it’s also better for you, your family members and your pets.

All things being equal, soy wax will burn anywhere between 30 percent to 50 percent longer than a paraffin candle. Again, this depends on the height and width of the candle, the length of the wick and other factors. To maximize how long your sox candle burns, you should trim the candle wick down to ⅛ - ¼ inch before relighting again. Don’t burn the candle for more than four hours, as this can cause the wax to overheat. Keep the candle away from drafts, and re-center the wick if it moves when the wax is melted.

Because of its large, defined crystal structure, paraffin wax has a higher melting point, between 120-160°F (49-71°C). Soy wax has a lower melting point than that, making it easier to burn in cooler environments or during colder seasons like winter. This lower point also lowers your risk of accidentally burning yourself if the candle gets knocked over or there’s some sort of accident. Soy wax can melt on its own if you live in a very hot area where temperatures rise into the lower end of that range. Because of the crystal structure, paraffin wax also tends to be harder and more brittle, while soy wax is softer and more pliable.

Due to the lack of soot and toxins released into the air, soy wax candles have a stronger scent profile than paraffin wax candles. The chemicals released by paraffin wax can interfere with the scent during burning, which kind of defeats the point of lighting a candle. Since you can’t add extra fragrances to candles (too much fragrance oil will compromise the wax), having a clean burn that really shows off the aroma is important. After all, you’re probably not burning the candle for light, but rather for its scent.