Glyphosate:
Commercially Available Options
Prepared for Auckland Council
June 2017
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Contents
Executive Summary ................................................................................................................................. 2
1.
Introduction .................................................................................................................................... 3
2.
Scope of the review ........................................................................................................................ 3
3.
Glyphosate ...................................................................................................................................... 3
4.
Commercially available products .................................................................................................... 4
5.
Additives ......................................................................................................................................... 5
5.1
Toxicity Information ................................................................................................................ 5
5.2
Toxicity Information ................................................................................................................ 6
5.3
Hazard Ratings ........................................................................................................................ 7
5.4
Assessing Products .................................................................................................................. 7
6. Recommendations......................................................................................................................... 12
References ............................................................................................................................................ 12
Appendix A: Glyphosate Products in NZ ............................................................................................... 13
Executive Summary
A review of commercially available glyphosate products in New Zealand has identified at least 30
formulations from 11 different suppliers/manufacturers, that may be considered as options for
Auckland Council (AC) contractors to use. In many cases, the publically available information failed
to identify whether there was an additive present or what that additive might be. In these
circumstances, the supplier was contacted directly and many did provide details of the class of
surfactant although often this was supplied on a confidential basis.
The products were assessed for relative toxicity and human health hazards on the basis of the
additives. Consideration of the human health hazard ratings were important to ensure that Council is
cognizant of the health and safety implications for its contractors, who handle and mix these
products.
The products were grouped:
RED: contains POEA or another toxic surfactant and/or has a corrosive rating,
ORANGE: POEA unconfirmed and/or had eye/skin irritation hazards, and
GREEN: no POEA and no human health hazard ratings.
While most glyphosate products in NZ still contain the tallow amine ethoxylate (POEA), there is a
growing list of products that contain less toxic surfactants. At present there are two suppliers in NZ
who supply two “green” glyphosate formulations each, and a third supplierS 7(2)(b)(ii)
3rd Party Commhas
confirmed
that they are working on a new POEA free glyphosate formulation.
This review recommends that Council consider the use of the least toxic glyphosate products for
contract maintenance works in areas that are accessible by the general public.
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1. Introduction
Auckland Council has responsibility for weed control within parks, reserves, sports grounds, gardens
and restoration areas. This work is undertaken using a variety of weed control methods, including
the use of agrichemicals and glyphosate. Internationally, the recent European assessment of
glyphosate has identified potential concerns around the toxicity of the additives, namely, the
surfactant (or surface active agent).
Auckland Council is keen to understand the formulations of the commercially available glyphosate
products in New Zealand, with a view to ensuring the least toxic formulations are used for Council
works where possible.
The review has identified more than 11 manufacturers in NZ with a long list of different
formulations, suitable for different purposes. The primary purpose of glyphosate manufactured in
NZ appears to be related to weed control in agricultural environments and pasture. Thirty one
different products were reviewed for the purposes of this report, with those products clearly
containing more toxic components being excluded.
2. Scope of the review
The scope of this review was to:
Research the current commercially available glyphosate preparations to establish a list of
products.
Identify the components and additives of each product, contacting the
suppliers/manufacturers for further information if required.
Prepare a brief report listing the available products, the chemical components and a
discussion on the relative toxicity and hazard associated with each product (based on available
information).
The information on each product was taken from the publically available Safety Data Sheet (SDS)
(previously called a Material Safety Data Sheet) and from verbal discussions with the manufacturers
where additional information or clarification was sought. At times the product information did not
identify the additives and in some cases the suppliers provided commercially sensitive information.
The suppliers contacted are identified with * in the summary table in Appendix A.
3. Glyphosate
Glyphosate exists in different forms (as salts with different counter ions) and it is the glyphosate acid
that is the active component. The concentration of the active ingredient present in the different
products is often confusing, with suppliers quoting the salt concentration and others the acid
concentration on the labels. Traditionally the acid is quoted and the form or salt then identified,
such as 360g/L glyphosate as the isopropylamine (IPA) salt. This actually refers to glyphosate acid at
360g/L with the IPA salt present at a concentration of 486 g/L. See Table 1 for the acid equivalence
of the salts. Some suppliers will sell this product as Glyphosate 480 giving the impression that it is a
more concentrated formulation.
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S 7(2)(b)(ii) 3rd Party Commercial Position
5. Additives
All of the glyphosate products reviewed contained one or more additives, as glyphosate typically
needs to be applied with a surfactant or wetting agent to be effective. The wetting agent enables the
large glyphosate molecule to pass through the cuticle or outer membrane of the foliage. Additional
surfactant may be tank-mixed with the glyphosate product as required to achieve the required
wetting, depending on the foliage being treated. Auckland Council contractors may add a further
surfactant to increase the uptake/effectiveness if rain is imminent or the weeds are particularly
dusty.
There are a number of classes of surfactants and these are based around the molecular structure of
the compound. These ingredients are often misleadingly labelled as non-hazardous or inert as the
SDS reporting rules do not necessarily require these additives to be identified if they have been
considered non-hazardous. With the recent focus internationally on the license renewal of
glyphosate in Europe, the toxicity of the additives is now being scrutinised more closely.
Commercially available formulations of glyphosate are known to often be more acutely toxic than
pure glyphosate.
Below is a quick summary of some of the surfactants commonly added to glyphosate formulations.
The additives in the commercial products reviewed for this report are shown in Table 4. While many
of the products specifically identify the additives, there are quite a number that identify the
additives only as “surfactant” or “inert or non-hazardous ingredient”. In this instance the NZ supplier
was contacted directly and asked for further information. In some cases, the supplier provided
details of the additives on a confidential basis, in others, the suppliers declined to respond or
provide further information. Three of the products did not identify any additives but the hazard
ratings indicated more than just glyphosate present in the formulation.
5.1 Toxicity Information
The standard surfactant traditionally added to glyphosate is polyethoxylated tallow amine (POEA) –
a non-ionic surfactant. The POEA surfactant (tallow is a mixture of fats with different chain lengths)
has typically provided good wetting qualities and is easily mixed with glyphosate. Recent
assessments of POEA however, have identified that the surfactant is more toxic than the glyphosate
active ingredient.
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5.3 Hazard Ratings
Safety Data Sheets (SDS) identify the health or environmental hazards associated with each product.
SDS documents must be updated regularly to ensure the sheets are not greater than 5 years old. The
ratings are assigned by the Environmental Protection Agency (EPA) at the time of product
registration. The ratings assist with identification of the less hazardous products; however, the
ratings are not updated over time to reflect new information, even though the SDS date is. This
means that the rating information on the latest SDS for a product registered 10 years ago might be
inconsistent with the ratings that the EPA might assign this product if it was being registered for the
first time this year. For this reason, the date of product registration has also been included in the
spreadsheet of reviewed products (see Appendix A).
The hazard ratings are allocated to human health and environmental categories and are ranked from
A to D or E depending on the severity of the effect, with A being the most acute and E being the
least. No hazard rating means that product does not cause a hazard in this category. All products
reviewed had a rating for environmental hazards, with the most common being 9.1B (ecotoxic in
aquatic environment) or 9.1D (slightly harmful to aquatic environment). Other environmental ratings
included: 9.1A (very ecotoxic in aquatic environment), 9.2B (ecotoxic in soil), and 9.3C (harmful to
terrestrial vertebrates).
The human health ratings included:
6.1 D and E (acutely toxic – harmful or may be harmful as aspiration hazard)
6.3 A and B (irritating to skin or mildly irritating to skin)
6.4 A (irritating to eye)
6.8 B (suspected human reproductive or developmental toxicant)
6.9 B (toxic to human target organs or sys)
8.2 B corrosive to dermal tissue
8.3 A corrosive to ocular tissue.
5.4 Assessing Products
The objective of this review was to identify the least toxic formulations of glyphosate commercially
available in NZ and understand the relative toxicity of the additives. POEA has been identified
internationally and through a recent MSc study for the Department of Conservation, as more toxic to
lizards and other species than glyphosate. On this basis products containing POEA were flagged as
“red”. The presence of other toxic surfactants (although not necessarily identified) also resulted in a
“red” rating. All other products that have category 8 corrosive hazard ratings have also been flagged
as “red” due to the potential health and safety issues for contractors’ handling/mixing/diluting these
products. A list of the products is shown in Table 4.
Products identified as “green”, with the lowest toxicity, identified only aquatic hazards, with no
human health ratings noted. These products were confirmed as not containing POEA. While other
products (in particular, the Monsanto ones) also only identify the 9.1 B hazard rating, the supplier
did not respond and/or confirm that no POEA was included in the formulation.S 7(2)(b)(ii) 3rd Party Commercial Position
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Products identified as “orange” either:
The supplier did not respond or confirm that no POEA was included, or
The product SDS included human health hazard ratings.
S 7(2)(b)(ii) 3rd Party Commercial Position
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S 7(2)(b)(ii) 3rd Party Commercial Position
9
S 7(2)(b)(ii) 3rd Party Commercial Position
10
S 7(2)(b)(ii) 3rd Party Commercial Position
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6. Recommendations
The review of commercially available glyphosate products in New Zealand has identified at least 30
formulations from 11 different suppliers/manufacturers. In many cases, the publically available
information failed to identify whether there was an additive present or what that additive might be.
In these circumstances, the supplier was contacted directly and given the opportunity to provide
further information. Many did provide details of the class of surfactant although this was often
supplied on a confidential basis.
The products were assessed for relative toxicity and human health hazards on the basis of the
additives. Consideration of the human health hazard ratings were important to ensure that Council is
cognizant of the health and safety implications for its contractors, who handle and mix these
products.
The products were grouped to reflect:
RED: contains POEA or another toxic surfactant and/or has a corrosive rating,
ORANGE: POEA unconfirmed and/or had eye/skin irritation hazards, and
GREEN: no POEA and no human health hazard ratings.
While most glyphosate products in NZ still contain the tallow amine ethoxylate (POEA), there is a
growing list of products that contain less toxic surfactants. At present there are two suppliers in NZ
who supply two “green” glyphosate formulations each, and a third supplierS 7(2)(b)(ii) 3rd Party Commhas
confirmed
that they are working on a new POEA free glyphosate formulation.
This review recommends that Council consider the use of the least toxic glyphosate products for
contract maintenance works in areas that are accessible by the general public.
References
Carpenter, J. K. (2013). Evaluating the effect of glyphosate formulations on the New Zealand
common skink (Oligosoma polychroma) (Honours thesis). Victoria University of Wellington,
Wellington.
Armstrong, J. and Lancaster, S. Herbicide How-to: Maximising Glyphosate Activity. Oklahoma
Cooperative Extension Service Fact Sheet PSS-2783. 2pp.
Castro, M.J.L, Ojeda, C. and Cirelli, A.F. (2014). Advances in surfactants for agrochemicals. Environ.
Chem. Lett. 12:85-95.
Diamond, G.L. and Durkin, P.R. (1997). Effects of Surfactants on the toxicity of glyphosate, with
specific reference to RODEO. SERA Technical Report SERA TR 97-206-1b. 32pp.
Safety Data Sheets for the products reviewed.
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S 7(2)(b)(ii) 3rd Party Commercial Position
13
S 7(2)(b)(ii) 3rd Party Commercial Position
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