Formation of formaldehyde from limonene in scented household products
BRUSSELS / STUTTGART (29 January 2016) ̶ In mid-January, BBC linked limonene in scented household products, including scented candles, to potential health hazards due to the formation of formaldehyde when the limonene reacts with ozone in their television program “Trust me I am a Doctor”.
The results of the underlying experiment were reported on BBC.com, and the story has been replicated on many websites inside and outside the U.K. since and unsettled consumers about the safe use of scented candles.
ECA would like to provide some perspective to address the misinterpretations contained in the programme and online article.
Limonene is a terpene (one of many) that occurs naturally and is used in fragrances both as a synthetically derived ingredient and also as part of many natural essential oils. The article suggested that scented cleaning products, air-fresheners and candles create undue levels of formaldehyde as a result of the emission of limonene and its subsequent reaction with ozone.
From a scientific point of view, the article left many questions unanswered. ECA therefore contacted Professor Alastair Lewis of the National Centre for Atmospheric Science (NCAS) at the University of York (U.K.) who supposedly performed the experiments for BBC. Prof. Lewis provided some helpful background information for a proper evaluation of the article:
In conclusion, the BBC programme and article (and the numerous follow-ups on other websites) are just some other scare-mongering stories with frighteningly little significance that willingly sacrifice sound science for getting higher ratings.
The safety of scented candles and their ingredients is of utmost importance to the European candle industry and has been part of decades of scientific research. Strict legal requirements and voluntary commitment on top of that make sure that consumers can use scented candles safely.