Metaldehyde

Metaldehyde
IUPAC name r-2, c-4, c-6, c-8-tetramethyl- 1,3,5,7-tetroxocane
Other names 2,4,6,8-tetramethyl-1,3,5,7- tetraoxocanemetacetaldehyde
Identifiers
CAS number	108-62-3 Y
KEGG	C18744 N
Jmol-3D images	Image 1
SMILES CC1OC(C)OC(C)OC(C)O1
Properties
Molecular formula	C8H16O4
Molar mass	176.212 g/mol
Density	1.27 g/cm³
Melting point	246°C
Boiling point	sublimes at 110-120 °C
N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Metaldehyde is an organic compound with the formula (CH₃CHO)₄. It is commonly used as a pesticide against slugs, snails, and other gastropods. It is the cyclic tetramer of acetaldehyde.^[1]

Production and properties

Metaldehyde is obtained in moderate yields by treatment of acetaldehyde with various acid catalysts, such as hydrogen bromide. The reaction is reversible, upon heating to about 80 °C, metaldehyde reverts to acetaldehyde. Metaldehyde exists as a mixture of stereoisomers, molecules that differ with respect to the relative orientation of the methyl groups on the 8-membered ring.

Uses

As a pesticide

It is sold under various trade names as a molluscicide, including Antimilice, Ariotox, Blitzem (in Australia), Cekumeta, Deadline, Halizan, Limatox, Limeol, Meta, Metason, Mifaslug, Namekil, Slug Fest Colloidel 25, and Slugit. Typically it is applied in the form of slug pellets, which normally include a wheat bait. Metaldehyde acts on the pest by contact or ingestion, and the aqueous environment inside the pest's cells readily hydrolyzes metaldehyde into acetaldehyde, the molecule associated with an alcohol hangover.

Metaldehyde-containing baits should be used with caution as they are toxic to dogs and cats.^[2]

Other uses

Metaldehyde is also used as a camping fuel. It may be purchased in a tablet form to be used in small stoves, and for preheating of Primus type stoves. It is sold under the trade name of "META" by Lonza Group of Switzerland.

Safety

Metaldehyde has a toxicity profile identical to that for acetaldehyde, being mildly toxic and irritatant to breathing at the 50 ppm level.

References

1. ^ Marc Eckert, Gerald Fleischmann, Reinhard Jira, Hermann M. Bolt, Klaus Golka “Acetaldehyde” in Ullmann's Encyclopedia of Industrial Chemistry, 2006, Wiley-VCH, Weinheim. doi:10.1002/14356007.a01_031.pub2.
2. ^ "Pests in Gardens and Landscapes". University of California, Davis. http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7427.html. Retrieved 2010-08-03. 

External links

• National Pesticide Information Center (NPIC) Information about pesticide-related topics.
  • Get Rid of Slugs and Snails, Not Puppy Tails! Case Profile - National Pesticide Information Center
  • Slugs and Snails - National Pesticide Information Center
• WHO/FAO Data sheet at inchem.org
• Solid Fuel Stoves - Metaldehyde mentioned
• Toxicology of metaldehyde

See also

• Slug controls (on Wikibooks)