Potential Sources of Indoor Air Pollution
Market Analysis and LiteratureReview


The report summarizes available in-formation on candles and incense aspotential sources of indoor air pollution.It covers market information and a re-view of the scientific literature. Themarket information collected focuseson production and sales data, typicaluses in the U.S., and data on the sourcesand quantities of imported products. Theestimated total sales of candles in 1999varied between $968 million and $2.3billion, while imports were $486 million.The U.S. imports and exports of incensein 1999 were $12.4 and 4.6 million, re-spectively. The scientific literature re-view gathered information regarding theemission of various contaminants gen-erated when burning candles and in-cense, as well as the potential healtheffects associated with exposure tothese contaminants. Burning candlesand incense can be sources of particu-late matter. Burning candles with lead-core wicks may result in indoor airconcentration of lead above EPA-rec-ommended thresholds. Exposure to in-cense smoke has been linked withseveral illnesses, and certain brands ofincense also contain chemicals sus-pected of causing skin irritation.This Project Summary was developedby the National Risk Management Re-search Laboratory’s Air Pollution Pre-vention and Control Division, ResearchTriangle Park, NC, to announce key find-ings of the research project that is fullydocumented in a separate report of thesame title (see Project Report orderinginformation at back).

Background and Approach The potential indoor air impacts of burn-ing candles and incense have drawn in-creased attention in recent years. Thereare three particular areas of concern.Candles with lead-core wicks have beenfound on the market and have beenshown to be a source of airborne leadwhen burned. Metal cores are used tostiffen wicks so they will not fall over andextinguish themselves as the surround-ing wax melts. Lead was commonly usedas a core material until 1974 when theU.S. candle manufacturing industry vol-untarily agreed to discontinue use of leadin wicks. However, candles with leadwicks have been found on the market byan academic as well as a consumer pro-tection group study. Most of the candlesfound that contained lead wicks were imported. Secondly, under imperfect combustionconditions, candles emit soot and cancause property damage by blackeningwalls, ceilings, and carpets. There havebeen an increasing number of complaints regarding black soot deposition in homesin the last decade. Candles are one source of soot. With candles, sooting occurs as a result of incomplete combustion. Candle composition, wick length, anddrafty conditions can all affect candle com-bustion. The amount of soot producedcan vary greatly depending on the type ofcandle. One type of candle can produceas much as 100 times more soot than another.Thirdly, incense smoke can be a major source of particulate emissions in indoor air.

The particulates produced when burn-ing incense can deposit in the respiratorytract. These emissions may contain con-taminants that can cause a variety ofhealth effects, including mutagenic effectsand airborne dermatitis.EPA is currently testing emissions fromcandles and incense to generate data.To support this effort, the report collectsand presents two types of data: (1) mar-ket information, and (2) literature on thepotential impacts of burning candles andincense on indoor air quality.The market information collected fo-cuses on production and sales data, typi-cal uses in the U.S., and data on thesources and quantities of imported prod-ucts. In addition, the report summarizesthe results of a scientific literature review.It reports the findings in the scientific lit-erature regarding the emission rates ofthe various contaminants generated whenburning candles and incense, as well asthe potential health effects associated withexposure to these contaminants.Market InformationPublicly available sources of data,mostly from the U.S. Bureau of the Census, as well as private market studiesand trade literature were consulted to pro-duce this summary of economic informa-tion regarding the candle and incensemarkets. Dialog Information Service and Internet searches were performed to iden-tify market and related information.

TheU.S. Bureau of Census was contacted toobtain import and export data. The Na-tional Candle Association was contacted to obtain industry data.The Census Bureau reports 107 manu-facturing establishments; however, indus-try estimates range from 160 to over 200 manufacturers. Many manufacturers are very small. Candle sales have been grow-ing rapidly in the last 10 years (10 to 15% per year), fueled by consumer interest in aromatherapy and increased demand for home fragrance products in general.There is a wide range in estimates of candle sales in the U.S. The Census Bu-reau reports a total value of shipments in1997 of $968 million; industry estimates put 1999 sales at $1.3 billion just for scented candles, and up to $2.3 billionfor all candles. The majority of candle imports are from China. A large portion of imports come from Hong Kong, Mexico,and Canada as well. There are no public data on incense manufacturers; private data show at least 26 manufacturers. Limited discussions with industry representatives indicate that there are probably many more very small incense manufacturers. The majority of incense imports are from India, China,and Thailand.

Potential Indoor Air Quality Impacts

Scientific literature, consumer interest group reports, and trade and industry stud-ies were consulted for this summary. Re-sources were identified through Medline,Toxline, a database of on-line journals,the National Candle Association, and ex-tensive web searches. The studies were diverse in origin; many of the incense studies were performed in Asia, where incense is commonly burned.Candles According to the literature reviewed, burning candles containing lead-corewicks can result in indoor air concentra-tions of lead above EPA-recommended thresholds.

All three of the scientific stud-ies, found analyzing indoor air concen-trations resulting from burning candleswith lead-core wicks, indicated that thisindoor air threshold was exceeded. Re-garding candles with non-lead metalcores, the literature did not indicate thatwicks made with zinc and tin emitted thesemetals at concentrations that would raisehealth concerns when burned indoors.In addition to lead, consumers are ex-posed to concentrations of organic chemi-cals, such as formaldehyde, acetaldehyde,and acrolein. One study showed worst-case scenario candle emissions contain-ing levels of these three chemicals thatexceeded EPA-recommended thresholds.Other studies indicated no health hazards. Sooting can occur when combustion conditions are impaired when burning candles. Scented candles are more likely to produce soot than unscented candles. Sooting can cause property damage byblackening surfaces. Although soot par-ticles are very small and can potentiallypenetrate the deepest areas of the lungs,studies regarding potential human healtheffects associated with soot from candleswere not found in the literature search.IncenseLarge quantities of particulate matterare generated when burning incense.Studies that examined the emissions ofspecific contaminants from incense smokeindicated that benzene and carbon mon-oxide may be emitted at concentrationsthat could pose human health risks. Sev-eral studies indicated links between exposure to incense smoke and health effects, such as cancer, asthma, and contact dermatitis. Some studies indicated possible mutagenic and genotoxic effects.

    So this is why you should not buy, in my opinion, scented candles or incense sticks that are sold everywhere and produced all over the world, and made of polyaromatic polycyclic substances and mineral formulas derived from petroleum, 100 % synthetic. Hand made incense sticks are really rare nowadays.

    Industry tries to copy nature sinthetically and it's attempt to make money out of inorganic minerals rather than organic living plants, introduces a risk factor that we should take care of. The best way to behave ( when legislations do not take care of public health for some reason or another ), is not to buy a product that contains such substances.

    Incense grains, ritual incenses, and herbs, together with wood and roots, are 100% organic, and if youcan find them "not transformed" or "genetically improved", ( or "cultivated without hormons ") and "without additives" they should be safe. "Bio" already stands for "New" in most of the cases, so don't take care of this word, that has already shown too many times to be a "selling word" rather than a control, which is most of the times carried out by the same firm that makes the product!!!

    Incense sticks and candles, that have had a market expansion of 15% every year in the last decade, and have been "considered by industry" as a way to make a lot of money, are the kind of unnecessay items I would avoid.

  to be continued....work in progress...

jedi simon