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CandlesFor centuries, candles have cast a light on man's progress. However, there is very little known about the origin of candles.It is the Romans who are credited with developing the wick candle, using it to aid travelers at dark, and lighting homes and places of worship at night.It was not until the Middle Ages when beeswax, a substance secreted by honey bees to make their honeycombs, was introduced. Beeswax candles were a marked improvement over those made with tallow, for they did not produce a smoky flame, or emit an acrid odor when burned. Instead, beeswax candles burned pure and clean. The growth of the whaling industry in the late 18th century brought the first major change in candlemaking since the Middle Ages, when spermaceti, a wax obtained by crystallizing sperm whale oil, became available in quantity. Like beeswax, the spermaceti wax did not elicit a repugnant odor when burned. Historians note that the first "standard candles" were made from spermaceti wax. Further developments in candlemaking occurred in 1850 with the production of paraffin wax made from oil and coal shales.Of greatest significance was its cost paraffin wax was more economical to produce than any preceding candle fuel developed. And while paraffin's low melting point may have posed a threat to its popularity, the discovery of stearic acid solved this problem.By this period, most candles being manufactured consisted of paraffin and stearic acid. While modern candle-making processes vary, most candles are made through the timeless process of placing a cotton wick into wax which is then molded, dipped, extruded, pressed, rolled, drawn or filled into a desired shape and size. A candle consists primarily of wax and a wick. Many candles also contain dyes or pigments for color and fragrances for scent as well as other minor ingredients.Although some candles reportedly contain lead wicks. When a candle with lead wick is lit, the whole house may be poisoned. It's been known for some time that burning candles with lead-treated wicks can release fine particles of the toxic metal into the air. However, adding lead to the wick stiffens it and gives a more even burn. Lead is particularly dangerous for children because it hampers brain development. Now researchers at the US Environmental Protection Agency (EPA) in Durham, North Carolina have found that burning a leaded-wick candle raises particulates to dangerous levels not just near the candle but throughout the house. Shirley Wasson and her team at the EPA measured particulate levels from eight brands of leaded-wick candles made in the Far East. They reported in a issue of The Science of the Total Environment that burning just one average leaded-wick candle for only four hours will raise the lead levels to 6.2 micrograms per cubic metre in the room with the candle and to 2 µg/m3 throughout the rest of the house. The US National Air Quality Standard for lead set by the EPA is 1.5 µig/m3. The researchers say the worst candle they tested would raise lead levels to more than 13 times the safe limit. So imagine how much worse it must be in a hut with just candles for lighting! There are safer alternatives for wicks such as zinc, but these are more expensive. Related topicsExternal links and referencesContributorsUser:Grant Ballard-Tremeer 25 August 2003 User:Dr Karabi Dutta 23 February 2004Comments | |
Page created:
25 August 2003; Last edited:
23 February 2004; Version: 1 | |
Pagename: Candle @HEDON: FCAA | |
