What a wick is made of

Pick up any candle and look at the wick. You cannot tell what is inside it. And the law still allows it to contain lead.

So how would you know?

You might trust the law. In 2003 the US Consumer Product Safety Commission banned lead-cored wicks. But the rule set a limit, not a zero. A wick's metal core can still contain up to 0.06 percent lead by weight and be sold legally today.

You might trust the industry. But the industry already made that promise once. In 1974, candle makers agreed among themselves to stop using lead-cored wicks, and some went back to them. When a survey checked candles for sale around Washington, DC in 1999, about 30 percent had metal-cored wicks, and about one in ten of those had lead in the wick.

You might trust a wick that is not lead at all. Metal cores are there to keep a soft braided wick standing upright in melted wax, and when the ban was written, practically every metal-cored wick made in the US was zinc. Those zinc cores carried trace lead of their own, about 0.01 percent. A zinc wick can be perfectly legal and still not be free of lead.

And whatever is in the wick does not stay there. It burns. In 2000, researchers at the University of Michigan burned candles with metal-core wicks from 14 brands and measured what came off them. Zinc left the wicks at up to 124 micrograms an hour.

So there is one sure way to know what your wick is putting into the room: choose a wick with no metal in it at all.

That is the wick we chose. Our candles burn on three cotton wicks with no core inside. No lead, no zinc, no tin. To keep them standing straight, we coat them in soy wax instead.

Look at our wick. What you see is what there is: cotton, and a coat of soy wax.

See all four candles

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Sources

• The 2003 ban; the 0.06 percent limit; the 1974 voluntary agreement; the 1999 Washington, DC survey; zinc cores and their trace lead. Consumer Product Safety Commission, "Metal-Cored Candlewicks Containing Lead and Candles With Such Wicks," final rule, Federal Register 68, no. 75 (April 18, 2003): 19142–19148, 16 CFR Part 1500. https://www.govinfo.gov/content/pkg/FR-2003-04-18/html/03-9255.htm
• Braided wicks and their core materials. National Candle Association, "Elements of a Candle: Wicks." https://candles.org/elements-of-a-candle-wicks/
• Zinc released from metal-core wicks. Nriagu, J. O., and Kim, M.-J. "Emissions of lead and zinc from candles with metal-core wicks." Science of the Total Environment 250, no. 1–3 (2000): 37–41. PubMed 10811249. https://pubmed.ncbi.nlm.nih.gov/10811249/
• Our wicks. Glow Guardian product specification: three cotton wicks, lead-free, no core, pre-waxed in soy wax.