Polyethoxylated tallow amine: Difference between revisions

 

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POEA strongly [[adsorbs]] so that it is bound to soil and other particulates, which reduces exposure to aquatic or soil-dwelling organisms.<ref name=”Rodríguez-Gil2021″>{{cite book |last1=Rodríguez-Gil |first1=Jose Luis |last2=Prosser |first2=Ryan S. |last3=Duke |first3=Stephen O. |last4=Solomon |first4=Keith. R. |title=Reviews of Environmental Contamination and Toxicology Volume 255: Glyphosate |date=2021 |publisher=Springer International Publishing |isbn=978-3-030-68483-9 |pages=129–205 |url=https://link.springer.com/chapter/10.1007/398_2020_56 |language=en |chapter=Ecotoxicology of Glyphosate, Its Formulants, and Environmental Degradation Products}}</ref> This also makes it difficult to measure POEA in the environment.<ref name=”Thompson2011″>{{cite book |title=Ecological Impacts of Toxic Chemicals |date=2011 |publisher=Bentham Science Publishers |location=Erscheinungsort nicht ermittelbar |isbn=978-1-60805-663-7 |url=https://edepot.wur.nl/192582 |language=en |chapter=Ecological Impacts of Major Forest-Use Pesticide|last=Thompson|first=Dean}}</ref><ref name=”Rodríguez-Gil2021″/> In laboratory experiments, POEA has a half-life in soils of less than 7 days. Washout from soil is minimal, and the estimated half-life in bodies of water is about 2 weeks. Field experiments have shown that the [[half-life]] of POEA in shallow waters is about 13 hours, “further supporting the concept that any potential direct effects of formulated products on organisms in natural waters are likely to occur very shortly post-treatment rather than as a result of chronic or delayed toxicity.”<ref name=Thompson2011/>{{rp|96}}

POEA strongly [[adsorbs]] so that it is bound to soil and other particulates, which reduces exposure to aquatic or soil-dwelling organisms.<ref name=”Rodríguez-Gil2021″>{{cite book |last1=Rodríguez-Gil |first1=Jose Luis |last2=Prosser |first2=Ryan S. |last3=Duke |first3=Stephen O. |last4=Solomon |first4=Keith. R. |title=Reviews of Environmental Contamination and Toxicology Volume 255: Glyphosate |date=2021 |publisher=Springer International Publishing |isbn=978-3-030-68483-9 |pages=129–205 |url=https://link.springer.com/chapter/10.1007/398_2020_56 |language=en |chapter=Ecotoxicology of Glyphosate, Its Formulants, and Environmental Degradation Products}}</ref> This also makes it difficult to measure POEA in the environment.<ref name=”Thompson2011″>{{cite book |title=Ecological Impacts of Toxic Chemicals |date=2011 |publisher=Bentham Science Publishers |location=Erscheinungsort nicht ermittelbar |isbn=978-1-60805-663-7 |url=https://edepot.wur.nl/192582 |language=en |chapter=Ecological Impacts of Major Forest-Use Pesticide|last=Thompson|first=Dean}}</ref><ref name=”Rodríguez-Gil2021″/> In laboratory experiments, POEA has a half-life in soils of less than 7 days. Washout from soil is minimal, and the estimated half-life in bodies of water is about 2 weeks. Field experiments have shown that the [[half-life]] of POEA in shallow waters is about 13 hours, “further supporting the concept that any potential direct effects of formulated products on organisms in natural waters are likely to occur very shortly post-treatment rather than as a result of chronic or delayed toxicity.”<ref name=Thompson2011/>{{rp|96}}

POEA is toxic to aquatic species like fish and amphibians. Like other surfactants, it can affect [[membrane transport]] and can often act as a general [[narcotic]].<ref name=Thompson2011/> In mixtures such as [[glyphosate-based herbicides]], the low aquatic toxicity of glyphosate results in surfactants like POEA having a higher relative toxicity than the active ingredient. In the US during the 1980s and 1990s, glyphosate formulations intended for aquatic use, such as Rodeo, discontinued use of POEA as surfactants are generally not needed for aquatic use and POEA concentrations in bodies of water would be close to increased risk levels for aquatic organisms.<ref name=”Rodríguez-Gil2021“/>

POEA toxic to aquatic species like fish and amphibians. Like other surfactants, it can affect [[membrane transport]] and can often act as a general [[narcotic]].<ref name=Thompson2011/> In mixtures such as [[glyphosate-based herbicides]], the low aquatic toxicity of glyphosate results in surfactants like POEA having a higher relative toxicity than the active ingredient. In the US during the 1980s and 1990s, glyphosate formulations intended for aquatic use, such as Rodeo, discontinued use of POEA generally not needed for aquatic use POEA in water to risk aquatic organisms.<ref name=””/>

==Human toxicity==

==Human toxicity==

Range of non-ionic surfactants derived from animal fats

Polyethoxylated tallow amine (also polyoxyethylene tallowamine, POE-tallowamine) refers to a range of non-ionic surfactants derived from animal fats, or tallow. They are a class of polyethoxylated amines (POEAs). The abbreviation ‘POEA’ is often erroneously used to refer to POE-tallowamine. They are used primarily as emulsifiers and wetting agents for agrochemical formulations, such as pesticides (e.g. glyphosate).

Animal fat is hydrolysed to give a mixture of free fatty acids, typically oleic (37–43%), palmitic (24–32%), stearic (20–25%), myristic (3–6%), and linoleic (2–3%). These are then converted to fatty amines via the nitrile process before being ethoxylated with ethylene oxide; this makes them water-soluble and amphiphilic. The length of the fatty tail and degree of exothylation will determine the overall properties of the surfactant.^{[citation needed]}

The polyethoxylated tallow amine used as a surfactant is referred to in the literature as MON 0139 or polyoxyethyleneamine (POEA). It is contained in the herbicide Roundup. An ethoxylated tallow amine (CAS No. 61791-26-2), is on the United States Environmental Protection Agency List 3 of Inert Ingredients of Pesticides.”^[1]: 14

Roundup Pro is a formulation of glyphosate that contains a “phosphate ester neutralized polyethoxylated tallow amine” surfactant; as of 1997 there was no published information regarding the chemical differences between the surfactant in Roundup and Roundup Pro.^[1]: 14

POEA concentrations range from <1% in ready-to-use glyphosate formulations to 21% in concentrates.^[2] POEA constitutes 15% of Roundup formulations and the phosphate ester neutralized polyethoxylated tallow amine surfactant constitutes 14.5% of Roundup Pro.^[1]: 14

Surfactants are added to glyphosate to allow effective uptake of water-soluble glyphosate across plant cuticles, which are hydrophobic, and reduces the amount of glyphosate washed off plants by rain.^[3]: 96

POEA strongly adsorbs so that it is bound to soil and other particulates, which reduces exposure to aquatic or soil-dwelling organisms.^[4] This also makes it difficult to measure POEA in the environment.^[3][4] In laboratory experiments, POEA has a half-life in soils of less than 7 days. Washout from soil is minimal, and the estimated half-life in bodies of water is about 2 weeks. Field experiments have shown that the half-life of POEA in shallow waters is about 13 hours, “further supporting the concept that any potential direct effects of formulated products on organisms in natural waters are likely to occur very shortly post-treatment rather than as a result of chronic or delayed toxicity.”^[3]: 96

POEA can be toxic to aquatic species like fish and amphibians. Like other surfactants, it can affect membrane transport and can often act as a general narcotic.^[3] In mixtures such as glyphosate-based herbicides, the low aquatic toxicity of glyphosate results in surfactants like POEA having a higher relative toxicity than the active ingredient. In the US during the 1980s and 1990s, glyphosate formulations intended for aquatic use, such as Rodeo, discontinued use of POEA. POEA-containing formulations at the time could result in potentially hazardous levels for aquatic organisms when applied to bodies of water, and surfactants generally are not needed for aquatic herbicide use.^[4] Aquatic organism exposure risk to terrestrial formulations with POEA may occur due to drift, agricultural runoff or temporary water pockets.^[5][6] While laboratory studies can show effects of glyphosate formulations with POEA on aquatic organisms, similar observations rarely occur in the field when instructions on the herbicide label are followed.^[7]

A review published in 2000 examining the toxicity of POEA and other components in glyphosate formulations found “no convincing evidence for direct DNA damage in vitro or in vivo, and it was concluded that Roundup and its components do not pose a risk for the production of heritable/somatic mutations in humans. …Glyphosate, AMPA, and POEA were not teratogenic or developmentally toxic. …Likewise there were no adverse effects in reproductive tissues from animals treated with glyphosate, AMPA, or POEA in chronic and/or subchronic studies.”^[8]

Another review, published in 2004,^[2] said that with respect to glyphosate formulations, “experimental studies suggest that the toxicity of the surfactant, polyoxyethyleneamine (POEA), is greater than the toxicity of glyphosate alone and commercial formulations alone. There is insufficient evidence to conclude that glyphosate preparations containing POEA are more toxic than those containing alternative surfactants. Although surfactants probably contribute to the acute toxicity of glyphosate formulations, the weight of evidence is against surfactants potentiating the toxicity of glyphosate.”