World Library  
Flag as Inappropriate
Email this Article

Methamidophos

Article Id: WHEBN0003586545
Reproduction Date:

Title: Methamidophos  
Author: World Heritage Encyclopedia
Language: English
Subject: Chlorpyrifos, Aldicarb, Food contaminant, Ethoprop, Methidathion
Collection: Anticholinesterases, Organophosphate Insecticides, Phosphoramidothioates
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Methamidophos

Methamidophos
Skeletal formula of methamidophos
Ball-and-stick model of the methamidophos molecule
Names
IUPAC name
O,S-Dimethyl phosphoramidothioate
Identifiers
 Y
ChEBI  N
ChEMBL  Y
ChemSpider  Y
Jmol-3D images Image
KEGG  Y
PubChem
Properties
C2H8NO2PS
Molar mass 141.1 g/mol
Density 1.31 g/cm³
Melting point 44.5 °C (112.1 °F; 317.7 K)
Boiling point thermally unstable
Hazards
R-phrases R20, R21
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 N  (: Y/N?)

Methamidophos, trade name "Monitor," is an insecticide.[1]

Crops grown with the use of methamidophos include potatoes[2] and some Latin American rice[3] Many nations have used methamidophos on crops, including developed nations such as Spain, United States, Japan, and Australia. Due to its toxicity, the use of pesticides that contain methamidophos is currently being phased out in Brazil. In 2009, all uses in the United States were voluntarily canceled.

Contents

  • Toxicity 1
  • Use 2
  • Use in poisoning 3
  • References 4
  • External Links 5

Toxicity

LD50 rates of 21 and 16 mg/kg for male and female rats, respectively. 10–30 mg/kg in rabbits, and dermal LD50 of 50 mg/kg in rats. It is rapidly absorbed through the stomach, lungs, and skin in humans, and eliminated primarily through urine.[4] It is a cholinesterase inhibitor.

Breakdown in soil is 6.1 days in sand, 309 days in water at pH 5.0, 27 days at pH 7.0, and 3 days at pH 9.0. Sunlight accelerates breakdown. It is uptaken through roots and leaves of plants.[4]

It is classified as a WHO Toxicity Class "Class 1b, Highly Hazardous", and its parent chemical, acephate, is "class III, Slightly Hazardous".

Use

Methamidophos is used in great quantities in ricefields in China.[5] Rice–fish culture is common in the southern parts of China as well as in many other rice-producing countries (e.g., Thailand, Malaysia, and the Philippines). Brown rice (unpolished) in this study contained double the concentration of polished rice. Both plants and animals did not degrade the pesticide well, and fish for human consumption in these cases contains methamidophos in concentrations roughly similar to brown rice.[5]

Use in poisoning

Methamidophos was found in dumplings (gyoza) manufactured in China for the Japanese market after a number of consumers became sick.[6]

References

  1. ^ http://www.alanwood.net/pesticides/class_insecticides.html
  2. ^ name="http://pmep.cce.cornell.edu/profiles/insect-mite/fenitrothion-methylpara/methamidophos/insect-prof-methamidophos.html"
  3. ^ Did Your Shopping List Kill A Songbird? Bridget Stutchbury, New York Times March 30, 2008
  4. ^ a b [2]
  5. ^ a b International Development Research Center
  6. ^ Japan Times http://www.japantoday.com/category/crime/view/china-launches-contaminated-dumplings-probe

External Links

  • Methamidophos in the Pesticide Properties DataBase (PPDB)


This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.