Aminopyralid

207.01

207.01

604-721-7

9S4EMJ60LF

DTXSID2034330

Off-white powder

2933399090

76.2

1.67

1.72 at 20 deg C/4 deg C

163.5 deg C

432.0±45.0 °C(Predicted)

215.1±28.7 °C

1.669

In water, 2.48 g/L (unbuffered, 18 deg C); 205 g/L (pH 7)

0-6°C

2.59X10-5 mPa /1.92X10-10 mmHg/ at 25 deg C

Odorless

Henry's Law constant = 1.74X10-12 atm-cu m/mol at 25 °C (est)

pKa = 2.56

NONH for all modes of transport

3

36

26

Xi

Stable at pH 5, 7 and 9 at 20 deg C for 31 days.

P305 + P351 + P338

H319

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

USEPA Office of Prevention, Pesticides and Toxic Substances, Pesticide Fact Sheet for Aminopyralid (August 10, 2005).[Available from, as of June 1, 2011: http://www.epa.gov/opprd001/factsheets/]

|Danger|H318 (85.39%): Causes serious eye damage [Danger Serious eye damage/eye irritation]|P264, P273, P280, P305+P351+P338, P310, P337+P313, P391, and P501|Aggregated GHS information provided by 267 companies from 6 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

For several good reasons, .... herbicides ... should be handled and applied only with full attention to safety measures that minimize personal contact. Many formulations contain adjuvants (stabilizers, penetrants, surfactants) that may have significant irritating and toxic effects. A number of premixed formulations contain two or more active ingredients; the companion pesticides may be more toxic than the principal herbicide. Good hygienic practice should not be disregarded just because a pesticide is reported to have a high LD50 in laboratory rodents. /Herbicides/

LD50 Rat oral >5000 mg/kg|LD50 Rat oral > 5000 mg/kg (equivalent to 1085 mg/kg bw expressed as aminopyralid) /Aminopyralid TIPA/|LD50 Rat dermal > 5000 mg/kg bw|LD50 Rat dermal > 5000 mg/kg (equivalent to 1085 mg/kg bw expressed as aminopyralid). /Aminopyralid TIPA/|LC50 Rat inhalation > 5.5 mg/L/ 4 hr

/BIRDS and MAMMALS/ /In an/ acute oral toxicity study conducted with northern bobwhite quail, ...the LD50 was greater than the highest dose tested , i.e., LD50 >292 mg a.e./kg bw. Clinical signs of toxicity (ruffled appearance, loss of coordination, lethargy, neck curl, prostrate posture, and/or lower limb weakness) were observed in oral treatments of 23 through 292 mg a.e./kg bw; therefore, the acute oral no-observed effect level is 14 mg a.e./kg bw. These effects were transitory, with time affected increasing with concentration. No treatment-related effects on body weight changes or feed consumption were observed.|/AQUATIC SPECIES/ Acute toxicity testing of estuarine/marine invertebrates was conducted using the mysid shrimp (Americamysis bahia) and Eastern oyster (Crassostrea virginica). In a 96-hr acute toxicity study of mysid shrimp, no mortality or sub-lethal effects were observed for aminopyralid-treated groups at up to the limit concentration of 100 mg a.e./L. The 96-hr LC50 value exceeds 100 mg a.e./L, and aminopyralid is classified as practically non-toxic to the estuarine/marine mysids on an acute exposure basis.|/AQUATIC SPECIES/ In the 96-hr acute shell deposition toxicity study of Eastern oysters, the EC50 value exceeds 89 mg a.e./L, and no mortality or sub-lethal effects were observed. Aminopyralid is classified as slightly toxic to the estuarine/marine mollusk on an acute exposure basis.|/AQUATIC SPECIES/ In the rainbow trout /96-hour acute/ test, partial loss of equilibrium was observed in 7% of the fish in the treatment group. In the test with bluegill sunfish, no mortality or sublethal effects were observed in the treatment group. For both species, the LC50 values are higher than 100 mg a.e./L, and aminopyralid is classified as practically non-toxic to freshwater fish on an acute exposure basis.|For more Ecotoxicity Excerpts (Complete) data for Aminopyralid (7 total), please visit the HSDB record page.

Aminopyralid's production may result in its release to the environment through various waste streams; its use as a herbicide(1) will result in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), a Koc range of 1.05 to 24.3(2), indicates that aminopyralid is expected to have very high mobility in soil(SRC). The pKa of aminopyralid is 2.56(2), indicating that this compound will partially exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(3). Volatilization of aminopyralid from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.7X10-12 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Aminopyralid is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.92X10-10 mm Hg at 25 °C(2). Biodegradation half-lives in soil ranging from 31.5 to 533.2 days(4) suggest that biodegradation is not an important environmental fate process in soil(SRC).|AQUATIC FATE: Based on a classification scheme(1), a Koc range of 1.05 to 24.3(2) indicates that aminopyralid is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 1.7X10-12 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). A pKa of 2.56(2) indicates aminopyralid will exist partially in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces is not expected to be an important fate process(SRC). According to a classification scheme(5), an estimated BCF of 3(SRC), from its log Kow of 0.201(2) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low(SRC). The compound readily photolyzed in water with a half-life of 0.6 days(7). In sediment-water systems, the biodegradation half-life range was 462 to 990 days(2), suggesting that biodegradation is not an important environmental fate process in water(SRC).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), aminopyralid, which has a vapor pressure of 1.92X10-10 mm Hg at 25 °C(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase aminopyralid may be removed from the air by wet or dry deposition(SRC). The compound readily photolyzed in water with a half-life of 0.6 days and weakly photolyzed on soil, with a half-life of 72 days reported(1); this suggests that the compound may be susceptible to direct photolysis in sunlight(SRC).

Aminopyralid is stable to hydrolysis in the environment(1); the compound was stable at pH 5, 7 and 9 and 20 °C for 31 days(2). The compound readily photolyzed in water with a half-life of 0.6 days and weakly photolyzed on soil, with a half-life of 72 days reported(1).

An estimated BCF of 3 was calculated in fish for aminopyralid(SRC), using a log Kow of 0.201(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Koc of aminopyralid ranges from 1.05 to 24.3 mL/g(1). A Koc range of 0.0 to 38.9 mL/g (mean 10.8 mL/g) has also been reported(3). According to a classification scheme(3), this Koc range suggests that aminopyralid is expected to have very high mobility in soil. The pKa of aminopyralid is 2.56(3), indicating that this compound will partially exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(4). Kd values ranging from 0.03 to 0.72 have been reported for aminopyralid(1).

The Henry's Law constant for aminopyralid is estimated as 1.7X10-12 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that aminopyralid is expected to be essentially nonvolatile from water and moist soil surfaces(2). Aminopyralid is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.92X10-10 mm Hg(3).

Occupational exposure to aminopyralid may occur through inhalation and dermal contact with this compound at workplaces where aminopyralid is produced or used. (SRC)

Aminopyralid (XDE-750) is rapidly absorbed, distributed and excreted following oral administration. Total 24-hour recoveries of the radioactivity were high for all groups ( about 41-59% and 33-43% of the administered dose in urine and feces, respectively). The absorption and excretion patterns of the (14)C moiety were similar among all groups. ... Tissue distribution and bioaccumulation of XDE-750 were minimal, with <0.73% of the administered dose being recovered in tissues 7 days after oral administration for all dosing groups. Highest levels of radioactivity were found in the skin and carcass. XDE-750 was excreted unchanged indicating an absence of metabolism. Of the total radioactivity in urine, parent accounted for about 96%, and of the total radioactivity in feces, parent accounted for 100%.|Four male Fischer 344 rats/group were dosed orally by gavage with (A) 50 mg/kg of (14)C-Aminopyralid (XDE-750-pyridine-2,6-(14)C) (radiochemical purity: 98.25%, specific activity: 28.6 mCi/mmole) or (B) 96 mg/kg of (14)C Aminopyralid-TIPA (triisopropanolamine) which was prepared from (14)C XDE-750-pyridine-2,6-(14)C with the appropriate amount of triisopropanolamine. Urine, fecal and plasma samples were collected for up to 120 hours post-dose. In the excretion profile, 42 to 46% (urine plus cage wash) and 51 to 54% of the administered dose was recovered in the urine and feces, respectively, for the two groups. The percentage of the administered dose recovered in the first 24 hours post-dose was 93 to 94%. The percentage of the administered dose recovered in the plasma was limited to 0.04 to 0.05% over the time course of sample collection. The peak plasma levels for both dosing regimens was within the first 15 minutes post-dose. ... /Triisopropanolamine salt/|The absorption, distribution, metabolism and excretion of aminopyralid were studied in three groups of three female New Zealand White (NZW) rabbits given single and multiple oral daily doses by gavage. Three non-pregnant animals received a single dose of radiolabelled test material at 371 mg/kg bw, three pregnant animals received a single dose of radiolabelled aminopyralid at 362 mg/kg bw on day 7 of gestation and another three pregnant animals received repeated daily doses of nonlabelled aminopyralid at 279 mg/kg bw from day 7 of gestation until day 21 of gestation, followed by a single dose of radiolabelled aminopyralid at 279 mg/kg bw on day 22 of gestation. The variation between doses administered was the consequence of inadvertently using different dose preparations, but this was judged not to affect the interpretation of the results. ...Additionally, plasma from rabbits that were not pregnant, from pregnant animals on day 7 of gestation and on day 22 of gestation and for comparison purposes from nonpregnant female Fischer 344 rats was used for studies of plasma protein binding with radiolabelled aminopyralid. ... The test material was 94.5% chemically and 98.25% radiochemically pure active ingredient and had a specific activity of 1.058 GBq/mmol. ...There was increased early renal excretion, shorter Tmax and higher plasma area under the curve of concentration-time (AUC) in pregnant rabbits given repeated doses, indicating more rapid and extensive absorption in these animals when compared with non-pregnant rabbit or pregnant rabbits given a single dose on day 7 of gestation. Plasma protein binding of aminopyralid was moderate, about 40-70%, and was greater in rats than in rabbits. In rabbits, it was slightly lower in pregnant animals on day 22 of gestation after pretreatment. In summary, the pharmacokinetic and plasma-protein-binding studies indicated a somewhat higher bioavailability in late-stage pregnant rabbits than in non-pregnant or early-stage pregnant rabbits, although the difference in terms of unbound compound was not more than twofold.|To compare the patterns of absorption, distribution, metabolism and excretion of aminopyralid and aminopyralid TIPA, two groups of four male Fischer 344 rats received single equimolar doses of either (14)C-aminopyralid at 50 mg/kg bw or (14)C-aminopyralid TIPA at 96 mg/kg bw by oral gavage. (14)C-aminopyralid TIPA was prepared using (14)C-aminopyralid by adding appropriate amounts of TIPA. The test material was 94.5% chemically and 98.25% radiochemically pure active ingredient. Both test materials had a specific activity of 1.058 GBq/mmol and were administered in 0.5% methylcellulose in distilled water. Dosing preparations containing aminopyralid (acid form) appeared to be much more like a suspension than did the TIPA salt, which was readily soluble. Aminopyralid was re-suspended before gavage by shaking by hand. Rats were fitted with indwelling jugular vein cannulae and blood samples (14) were taken at intervals until 120 hr after dosing. ... Throughout the study, the animals looked healthy and showed no changes in appearance or behavior. Calculated as the sum of renal excretion and remaining radioactivity in tissues and carcass, 46% and 43% of aminopyralid in the acid form and as the TIPA salt were absorbed, respectively. Fecal excretion amounted to about 50% for both compounds. Except for one male with 0.02% of the administered dose in the skin, no radioactivity at above the limit of quantitation of

XDE-750 was not metabolized to volatile compounds, including CO2.|Four male Fischer 344 rats/group were dosed once orally by gavage with 1000 (Group A) or 50 mg/kg (Group B) of (14)C Aminopyralid (XDE-750-pyr-2,6-(14)C) (radiochemical purity: 98.6%, specific activity: 27.4 mCi/mmol) or for 14 days with 50 mg/kg/day of Aminopyralid (purity: 99.5%), followed by a single dose of 50 mg/kg (Group C) of the radiolabeled compound. Urine and fecal samples were collected for up to 168 hours post-dose. ... In the urine, 96% of the administered dose was unmetabolized parent compound. In the feces, 100% of the administered dose was unmetabolized.

Four male Fischer 344 rats/group were dosed orally by gavage with (A) 50 mg/kg of (14)C-Aminopyralid (XDE-750-pyridine-2,6-(14)C) (radiochemical purity: 98.25%, specific activity: 28.6 mCi/mmole) or (B) 96 mg/kg of (14)C Aminopyralid-TIPA (triisopropanolamine) which was prepared from (14)C XDE-750-pyridine-2,6-(14)C with the appropriate amount of triisopropanolamine. Urine, fecal and plasma samples were collected for up to 120 hours post-dose. ... The plasma elimination half lives for the alpha phase were 0.338 and 0.509 hours for the A and B dosing regimens, respectively. For the beta phase elimination, the half lives for 8.84 and 13.0 hours for A and B, respectively. The urine elimination half lives for the alpha phase were 2.84 and 2.54 hours for A and B, respectively. For the beta phase, the half lives were 7.81 and 10.7 hours for A and B, respectively. ... /Triisopropanolamine salt/|The average alpha-phase elimination half-lives (T 1/2 alpha) of (14)C-XDE-750 equivalents were 2.85, 3.27, and 3.78 hours for the single low, repeated low, and single high dose groups, respectively. The average beta-phase urinary elimination half-lives (T 1/2 beta) of (14)C-XDE-750 equivalents were 10.23, 12.25, and 10.88 hours for the single low, repeated low, and single high dose groups, respectively.

/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/|/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/|/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/

aminopyralid

Emulsion, water in oil|Premix Partners: Fluroxypyr; Metsulfuron-methyl|Aminopyralid Technical (Dow Agrosciences LLC) Aminopyralid 95.3%|Cleanwave (Dow Agrosciences LLC) Aminopyralid 1.92%, Fluroxypyr meptyl 20.22%|Grazonnext HL (Dow Agrosciences LLC) Aminopyralid 8.24%, Dimethylamine 2,4-dichlorophenoxyacetate 41.26%

The WHO Recommended Classification of Pesticides by Hazard identifies aminopyralid as unlikely to present an acute hazard in normal use; Main Use: herbicide.

Adequate enforcement methodology, Liquid Chromatography/Mass Spectrometry/Mass Spectrometry (LC/ MS/MS), Method GRM 07.07, is available to enforce the tolerance expression.|For residues in soil and water, by LC/MS/MS.

Agrochemicals -> Herbicides|Herbicides