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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Glyphosate

= N-(Phosphonomethyl)glycine CAS[1071-83-6]

Trade name

Glyphosate (J, I, A, B): Roundup, Rodeo, Ortho Groundclear Total Vegetation Killer (5% glyphosate by mass (as isopropylamine salt)), TouchDown

Chemical formula

It is usually formulated as the isopropylamine salt and in case of the most common formulation Roundup Ultra combined with the surfactant polyoxyethylene amine (POEA) (Giesy et al., 2000). AMPA (amino-methyl-phosphonic acid) is degradation product. (ref. ID; 6751)

Chemical characteristics

Glyphosate (N-(phosphonomethyl)glycine): water solubility 10.5 g L-1 at 20 degrees C, log Pow -3.2 at 25 degrees C. (ref. ID; 6751)

Purpose for use

Non-selective, post-emergence herbicide. It is utilized for weed control, i.e. in agriculture, forestry, urban areas and even aquaculture. (ref. ID; 6751)

Toxicity

LD50 (oral): rat 4320 mg/kg.
The toxicity of technical-grade glyphosate to aquatic invertebrates is minor (LC50: >55 mg L-1 glyphosate, WHO, 1994). (ref. ID; 6751)
Glyphosate-containing herbicides are some of the most prevalently used agrochemicals in the world. In fact, many important food crops (wheat, corn, soybeans) have been genetically modified so they are resistant to these herbicides, providing weed control without crop damage. Glyphosate, glycine analogue and active ingredient in RoundUp and TouchDown, is relatively non-toxic (oral LD50=4320-5600 mg/kg) to rats (Committee 1979; Worthington 1983). For pesticide formulations, glyphosate is combined with additional chemicals, which are typically listed only as "inert ingredients" and whose toxicity may be unknown in combination with the active ingredient. For example, the commercial formation, but not glyphosate alone, significantly decreased the ADP/oxygen ratio at concentrations as low as 0.5 mM glyphosate (the lowest concentration tested), suggesting that exposure to the pesticide, but not the active ingredient alone, lead to mitochondrial dysfunction. (ref. ID; 7113)

Test organisms

Protozoa: Tetrahymena thermophila (ref. ID; 4500)
Oligochaeta: Aporrectodea caliginosa (ref. ID; 6072)
Oligochaeta: Eisenia fetida (ref. ID; 4582)
Oligochaeta: Lumbriculus variegatus (ref. ID; 6751)
Nematoda: Caenorhabditis elegans (ref. ID; 7113)