WHAT ARE MOSQUITO COILS?
A mosquito repelling incense
Made from pyrethrum powder - natural
insecticide made from the dried flower heads of
Chrysanthemum (C. cinerariifolium and C.
Shaped into a coil – burning begins from outer
end and moves into inner end producing
Typical coils 15cm from end to end, lasts 8
Actually a mixture of several compounds pyrethrins , cinerins.
Used to be made by grinding dried
chrysanthemum flowers into a powder.
Now solvent extraction is used.
In Asia 200 years ago, people discovered
that extracts from crushed crysanthemums
Used as ‘lice powder’ (famous usage by
Napoleon and his forces)
Relatively low toxicity - breaks down
Generally has low environmental impact
Mosquito coils were invented by Eiichiro Ueyama.
At first, he brought the pyrethrum seeds from America
to be planted and milled as a flea repellant (1885)
The flea repellant won Merit Prize in the 3rd National
Industrial Exhibition in Tokyo (1890)
After meeting an incense seller, he wanted to further
simplify the application of the powder – creating
Original production method
mix starch powder and dried mandarin orange skin
powder + pyrethrum powder,
knead it thoroughly,
put it into a wooden mortar,
then cut it into the form of stick incense (candle)
However, the starch-pyrethrum ‘candle’
mix burns too quickly (40 minutes).
Needs 2-3 candles for maximum effect
Wife, Yuki, proposed elongating and
thickening the candles and winding it
into a spiral (1895).
By 1920, a working prototype is
developed (after trial and error)
1957 – mass production, machine
HOW THEY ARE MADE
Starch (potato starch, corn starch, rice or wheat
Coconut flour mix
Dye (for colour)
Burning aids (sodium and potassium nitrate, sodium
0.5% mass of insecticide
HOW THEY ARE MADE
Dispersing from 16- 26% by weight on a dry basis potato starch in
water having a temperature of from 40- 60° C.;
Gelling the dispersed starch by adding sufficient water having a
temperature of from 80- 95° C. to the starch-water dispersion to raise
the temperature of the resulting mixture to above the gelling point of
Adding from 72- 83% by weight on a dry basis of a carrier, from 0.5-3% by weight on a dry basis of an insecticide and from 0- 2% by
weight on a dry basis of a burning aid to the gelled starch-water
Forming thin sheets from the carrier starch-water mixture;
Forming mosquito coils from the thin sheets;
Drying the formed mosquito coils with the provision that the ratio of
dry ingredients to water is within the range of from 1:1- 1:2.5.
Provides as much as 80% protection
Long term (8-10 hours) protection
Need no special equipment to be used
Chemically inert (unless ingested)
The odor and smoke – asthmatics threat
Although no flame, but sparks can be emitted
– fire hazard
Releases VOC (formaldehydes), PAHs and
particulate matter – hazardous to health
If used in badly ventilated area – indoor
pollution and discomfort
One coil – 75 to 150 times more smoke than
Osaka Foundation for Trade & Industry (2004). Eiichiro Ueyama ,
Developing and promoting insecticide together with pyrethrum.
Retrieved on 22 September 2010, from
Sumitomi Chemical Company, Limited (1973). Fumigant Insecticidal
Mixtures Of D-chrysanthemates. Retrieved on 22 September 2010, from
Weili, L., Junfeng, Z., Hashim, J.H., Jalaludin, J., Hashim, Z., Goldstein,
B. D. (2003). Mosquito Coil Emissions and Health Implications.
Environmental Health Perspectives 111 (12): 1454–1460
DAINIHON JOCHUGIKU Co.,Ltd. History of Kincho Corp. Retrieved on
27 September 2010 from
Histria Aromatica, 2005. The History of Pyrethrum. Retrieved in 27
September 2010 from