Sylvia Knight sknight@gmavt.net 802-425-2068 March 2012

The herbicide mix used currently at electric substations in Vermont includes glyphosate, imazapic, isopropylamine, chlorsulfuron, sulfometuron methyl, spreading agent, drift retardant and unidentified ingredients. No studies exist regarding the toxicity of this chemical mixture, used without notification or permit from Vermont Pesticide Advisory Council.


* was found in over 1/3 of stream samples during USGS studies (2002) of Midwest streams (Cox, C,2004).

* was found in downstream of waste-water facilities in USGS studies across the country (Kolpin et al, 2005).

* breaks down to AMPA, more persistent in soil than glyphosate, remaining up to 900 days (Cox, C, 1998).

* causes injury to desirable plants more than 160 feet away at low amounts (Breeze, V, 1992).

* hinders desirable plants’ ability to resist disease (Levesque, CA.,1992).

* is toxic in combination with spreading agents to amphibians, especially tadpoles (Bidwell JR, 1995).

* is toxic to water fleas, earthworms and fish (Cox, C. 1998).

* killed bees in a municipal application in Netherlands. (http://www.i-sis.org.uk/SIS38lettersToTheEditor.php )

* can act as a phosphorous source and stimulate algae growth in waterways (Austin, AP, 1991).

* can cause human health effects including eye irritation; blurred vision; swollen eye, face, joints; burning sensation, blisters, rapid heartbeat; elevated blood pressure; headache; nausea (Cox, C. 1998).

* in its pesticide products, is known to be a skin sensitizer, carcinogen, reproductive toxin, neurotoxin & to damage kidney and liver (Beyond Pesticides, 2009), and to disrupt hormone function (Gasnier, C et al, 2009).

* in Roundup, alters male sexual development in test rats by inhibiting cell processes (R.M.Romano et al, 2009)


* remains active in soil and water for long periods and moves easily offsite to other areas;

* kills plants at extremely low concentrations, inhibiting action of enzyme needed for building amino acids;

* can be harmful through drift during treatments to nearby plant communities;

* needs more study on long-term and reproductive toxicity to birds, fish, aquatic organisms, and non-target plants (Maciorowski, AF 1995a).

* may present risks to bees since chronic ingestion was not part of 1987 study sponsored by manufacturer.

* presents risks to those with “pre-existing diseases” of the respiratory system, eyes or skin, and is “acutely harmful” for aquatic plants (BASF, 2008).

* may cause developmental toxicity in fetus without maternal toxicity (Thurston County Health Dept, 2009).

ISOPROPYLAMINE (“inert” ingredient combined with glyphosate and imazapic; disclosed by EPA, 2009)

* is toxic to aquatic life;

* is a severe irritant to eyes, skin and respiratory system;

* is highly flammable and attacks copper (International Programme on Chemical Safety, 2001) .

* may damage the copper grounding grid in substations needed for safety and reliability at substations.


* can damage desirable plants at about 10 parts-per-trillion, not detectable in normal laboratory procedures;

* are about 100 times more toxic to plants than older herbicides;

* are persistent and mobile in soil and water, and can easily move offsite;

* can prevent seed or fruit formation in desirable plants through toxic drift during treatments or drift of SU-contaminated soil dust carried off-site by wind, without visible damage to the plant;

* are inducing weed resistance in both SU and imidazolinone (imazapic) herbicides (Maciorowski, AF,1995b).

* are related chemically to sulfonylurea medicines used to control insulin function (endocrine system) in humans with diabetes, so they may affect hormone systems in animals, humans (Colborn, T & Short, P. 1999).

SPREADING AGENT: GROUNDED SURFACTANT (exempt from EPA registration process)

* contains mix of aliphatic hydrocarbons, alcohol ethoxylates and fatty acids (Helena Co. 2002).

* enables herbicide to penetrate plant’s natural coating and enter plant tissues (Helena Co., 2008).

* contains alcohol ethoxylates which are toxic to insects and aquatic life (Haller, WT & Stocker, RK, 2003).

* is a moderate skin irritant, can cause irritation to eyes, nose, throat from chronic exposure. (Helena Co. 2002)

DRIFT RETARDANTS - either polyacrylamide or silicone-based (exempt from EPA registration process)

* several products contain approximately 70% unidentified ingredients.

* polyacrylamide breaks down to acrylamide, highly water soluble and a nerve toxin. (Smith, EA, 1997)

* acrylamide is considered by State of California to be a carcinogen. (Sanitek, 1997 MSDS)

* silicone components can remain in soil up to a year after application, especially in colder climates, and be inhaled, but no level of toxicity has been established. (Singh, UB et al 2000)

PESTICIDES AND CHEMICALS IN MIXTURES often show higher toxicity to wildlife at lower concentrations experienced in the environment than do single pesticides (Christiansen S et al, 2009).

ENDOCRINE DISRUPTING COMPOUNDS (EDCs) cause long-term health problems from immune or nervous system damage or developmental and reproductive deformities due to exposure at critical periods of development or at other periods of life. Such chemicals work at very low concentrations, contrary to assumptions used by regulatory systems (Colborn T et al, 1996). Risk-based standards do not yet consider the complex and delayed effects from exposure to low concentrations of EDCs (Krimsky, S, 2000).


Austin, AP et al (1991). Bulletin of Environmental Contamination and Toxicology 47; 29-35.

BASF (2008). Plateau. Material Safety Data Sheet. http://www.cdms.net/LDat/mp2LP005.pdf (2/12/10)

Beyond Pesticides (2009). ChemWatch Factsheet: Glyphosate. http://www.beyondpesticides.org/gateway/pesticide/glyphosate.htm (2/14/10)

Bidwell, JR and JR Gorrie (1995). Acute Toxicity of a herbicide to selected frog species: final Report. Curtin Ecotoxicology Program. Prepared for Dept. of Environmental Protection. Perth, Western Australia.

Breeze, V et al (1992). Annals of Applied Biology 121:669-677.

Christiansen, S et al (2009). Environmental Health Perspectives. http://ehp.niehs.nih.gov/members/2009/0900689/0900689.pdf

Colborn, T, Dumanoski, D & Myers, JP (1996). Our Stolen Future: are we threatening our fertility, intelligence, and survival? (New York: Dutton/Penguin, 1996)

Colborn, T and Short, P (1999). Toxicology and Industrial Health 15; 241-276.

Cox, Carolyn. (2004). Journal of Pesticide Reform 24; 4; 10-15.

Cox, Carolyn. (1998). Journal of Pesticide Reform 18; 3; 3-16.

Gasnier, C et al (2009). Toxicology 2009: 262: 184-191. http://www.biosafety-info.net/article.php?aid=621

Haller, WT & Stocker, RK, (2003). Environmental Toxicology & Chemistry 22; 3; 615-619.

Hayes, T et al (2006). Environmental Health Perspectives. Supplement 1, 114.

Helena Co. (2002). Grounded. Material Safety Data Sheet. http://www.cdms.net/LDat/mp0K9004.pdf (viewed 2/12/10).

Helena Co. (2008). Grounded. Specimen Label. http://www.cdms.net/LDat/ld0K9001.pdf (viewed 2/12/10).

International Programme on Chemical Safety (2001). Isopropylamine. International Chemical Safety Card #0908. http://www.inchem.org/documents/icsc/icsc/eics0908.htm

Kolpin, DW et al (2005). Science of the Total Environment 354; 191-197.

Krimsky, Sheldon (2000). Hormonal Chaos. (Baltimore, MD: Johns Hopkins University Press, 2000).

Levesque, CA and JE Rahe (1992). Annual Review of Phytopathology 30; 579-602.

Maciorowski, Anthony F. (1995a). Risk assessment for use of imidazolinone… www.epa.gov/pesticides/foia/reviews/129041/129041-003.pdf

Maciorowski, Anthony F. (1995b). Qualitative assessment of sulfonylurea herbicides and other ALS inhibitors. Environmental Fate and Effects Division. EPA. March 24, 1995.

Romano, RM et al (2009). Archives of Toxicology 84; 4; 309-317. www.springerlink.com/content/a5148x61g942u021/

Sanitek (1997). Material Safety Data Sheet. 41-A Drift Retardant. http://www.cdms.net/LDat/mp251001.pdf (viewed 2/15/10)

Singh, UB et al (2000). Environmental Science & Technology 34; 2; 266-273.

Smith, EA (1997). Ecotoxicology & Environmental Safety 37; 76-91.

Thurston County Dept. of Health (2009). Imazapic. www.co.thurston.wa.us/health/ehipm/pdf_terr/terrestrial actives/Imazapic.pdf (viewed 2/15/10)