CATEGORY: Pyrethrins (natural) and pyrethroids (synthetic)
Trade or other Names:
BOTANICAL: pyrethrin
SYNTHETIC: allethrin, cypermethrin, decamethrin, flucythrinate, prothrin, resmethrin
(ENVCHEM). Buhach, Anerin I or II, Insect Powder, Dalmation insect flowers, Jasmolin I or II, Trieste flowers
(NJDOH) Chrysanthemum Cinerariaefolium, Ofirmotox, Firmotox, Parexan and NA 9184 (Extoxnet).
Agricultural: Ingredient of insecticidal sprays for use in households, food-storage warehouses, animal facilities and factories and on domestic and farm animals; garden and indoor plant sprays; control of insects in fruit, vegetable, field crop, and vine cultivation (ENVCHEM).
Poison experimentally by ingestion, intraperitoneal, and intravenous route. Moderately toxic to humans by ingestion (Sax & Lewis, 1989). Pyrethroids are nerve poisons and affect the central and peripheral nervous system. Inhalation is probably the main route of occupational exposure to pyrethrins. Other ingredients in pyrethrin formulations such as solvents (petroleum distillates) may cause toxic effects. Acute exposure effects include dermatitis, diarrhea, headache, irritability, peripheral vascular collapse, tremors, vomiting and disturbance of liver enzymes. Allergic reaction have resulted in the following effects, fever, anaphylaxis (extreme hypersensitivity to a foreign protein or drug), hypersensitivity pneumonia, pallor, nasal congestion, sweating, swelling of the face, eyelids, lips and mucous membranes (ENVCHEM), (Worksafe).
No reports of chronic health effects. Animal data supports this. There are reports of acute allergic, anaphylactic and asthmatic reactions following exposure to unrefined pyrethrum dust. There are many reports of severe dermatitis from contact with unrefined pyrethrum (ENVCHEM). Sax & Lewis (1989) report that chronic exposure can cause liver damage.
Carcinogenic: No human data available and no detailed animal studies have been reported. Some pyrethroid products (Fenvalerate, Permethrin, Tetramethrin) are suspected carcinogens (ENVCHEM). Mutagenic: No human data or laboratory testing (ENVCHEM) Teratogenic: Reproductive effects: Based on animal tests, no teratogenic or embryotoxic effects are expected, but insufficient information (ENVCHEM).
Deltamethrin is resistant to breakdown by sunlight and air (ENVCHEM). Pyrethrins have little residual effect. In stored grain, 50% or more of the applied pyrethrins disappear during the first three or four months of storage. Pyrethrum compounds are broken down in water to non-toxic products. Pyrethrins are inactivated and decomposed by exposure to light and air (Extoxnet).
A wide range of LD50 values have been reported.
LD50 (oral, rat): 200-1500 mg/kg
Range may reflect differing purities.
LD50 (dermal, rat): greater than 1350 mg/kg (ENVCHEM)
Pyrethrin is extremely toxic to aquatic life, such as bluegill and lake
trout while it is slightly toxic to bird species, such as mallards (Extoxnet).
Two pyrethroid synthetic insecticides, permethrin and cypermethrin, break down in plants to produce a variety of products (Extoxnet).
ENVCHEM. ftp://alternatives.com/library/envchem/pyrethro.txt,
ftp://alternatives.com/library/envchem/pyrethri.txt
Extoxnet. http://ace.orst.edu/cgi-bin/mfs/01/pips/pyrethri.p34
New Jersey Department of Health. (Requires Adobe Acrobat Reader).
http://www.state.nj.us/health/eoh/rtkweb/1623.pdf
Sax, N.I. & Lewis, R.J. (1989) Dangerous Properties of Industrial Materials. 7th edition. Van Nostrand Reinhold, Melbourne.
Worksafe. http://www.worksafe.gov.au/worksafe/FULLTEXT/DOCS/h4/462.htm