Mepiquat chloride

149.66200

149.09700

246-147-6

X0S7YUN0EP

DTXSID1024170

Colorless hygroscopic crystals

2933399090

0

-2.82 (LogP)|log Kow = -2.82 @ pH 7

1.187 g/cu cm (technical material, 20 deg C)

223 °C

106 °C

Solubility in acetone, 20,000 mg/l; chloroform, 10,500 mg/l; ethanol 162,000 mg/l

0-6ºC

<2.3X10-6 Torr @ 25.3 deg C

LD50 in mice, rats (mg/kg): 780, 464 orally; in rats (mg/kg): >2000 dermally (BASF Agric. Chem. Div.)

Slightly sweet, musty smell

Stable in aqueous media (7 d at pH 1-2 and pH 12-13, 95 °C); stable in artificial sunlight.

NONH for all modes of transport

2

R22; R52/53

S61

TN4939200

Xn

Stable in aqueous media (7 d at pH 1-2 and pH 12-13, 95 deg C); stable in artificial sunlight.

P273

H302-H412

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

USEPA/Office of Pesticide Programs; Reregistration Eligibility Decision Document - Mepiquat Chloride. EPA 738-R-96-019 March 1997. The RED summarizes the risk assessment conclusions and outlines any risk reduction measures necessary for the pesticide to continue to be registered in the U.S.[Available from, as of May 6, 2003: http://www.epa.gov/pesticides/reregistration/status.htm]

|Warning|H302: Harmful if swallowed [Warning Acute toxicity, oral]|P264, P270, P273, P301+P312, P330, and P501

Large liquid spillage should be dammed-off and pumped into containers; soak up remainder with absorbent material and dispose of in accordance with local regulations. Solid spillage should be picked up with an industrial vacumm cleaner and disposed of in accordance with local regulations.

LD50 Mouse oral 780 mg/kg|LD50 Rat (male and female) oral 464 mg/kg|LD50 Rat dermal >2000 mg/kg

/BIRDS and MAMMALS/ The LD50 of the technical product in Northern bobwhite quail (Colinus virginianus) is >2,000 mg/kg. Only one bird death was reported during the study (at 2,000 mg/kg). Therefore, mepiquat chloride is practically nontoxic to avian species 50 on an acute oral basis. The 5-day LC50 of the technical product in Northern bobwhite quail (Colinus virginianus) and Mallard duck (Anas platyrhynchos) is >4,600 ppm, therefore, mepiquat chloride is practically nontoxic to avian species 50 on a subacute dietary basis. Because the LD50 falls within the range of 51-500 mg/kg, mepiquat chloride is moderately toxic to small mammals on an acute oral basis. Chronic and subchronic studies indicate that mammals are affected at relatively high concentrations. /from tables/|/AQUATIC SPECIES/ The 96-hr LC50 in Rainbow trout (Oncorhynchus mykiss) (static) and Bluegill sunfish (Lepomis macrochirus) (static) for pure mepiquat chloride (99%) showed this substance to be slightly toxic; technical material (46%) was described as practically nontoxic. A Freshwater Aquatic Invertebrate Life-Cycle Toxicity (Static Renewal) test reported a 21-day NOEC/LOEC of 12.5/25 (nominal) ppm and a MATC of 18.8 ppm in Waterflea (Daphnia) based on mortality of adults for pure mepiquat chloride (99%). The 96-hr LC50 in Sheepshead minnow (Cyprinodon variegatus) of technical product (54.6%) was >151 ppm (measured), which was described as practically nontoxic. No chronic toxicity studies for estuarine and marine fish were available for review by EPA. However, supplemental chronic toxicity studies with freshwater fish and invertebrates suggest low chronic toxicity. /from tables/|/AQUATIC SPECIES/ ...Blue-green algae is the most sensitive nonvascular aquatic plant tested. For ...vegetative vigor cabbage, tomato and carrots are the most sensitive dicots. No monocot endpoints were significantly reduced.|/OTHER TERRESTRIAL SPECIES/ The LD50 of the technical product in Honey bee (Apis mellifera) is >100 ug/bee. The results indicate that mepiquat chloride is practically nontoxic to bees on an acute contact basis. /from tables/

Mepiquat chloride's production may result in its release to the environment through various waste streams; it's use as a growth regulator for crops(1) will result in its direct release to the environment(SRC).

TERRESTRIAL FATE: Mepiquat chloride is a salt and will exist in the cationic form in the environment. Based on a classification scheme(1), Kd values of 9.88 to 25.0(2), and Koc values ranging from 67 to 4685(3) indicate that mepiquat chloride is expected to generally have moderate to slight mobility in soil(SRC) A Kd of 0.22 in sand suggests that mobility may be high in this type of soil(2). Volatilization from moist soil surfaces is not expected to be an important fate process because this compound is a salt. Biodegradation in aerobic soils is a major transformation pathway; laboratory half-lives of 3 to 21 days have been measured(2). The only detected metabolite is carbon dioxide(2). Half-lives of 3, 17, and 21 days were measured in field studies although, at higher application rates, half-lives of 6.5 to 87.2 days were reported(2).|AQUATIC FATE: Mepiquat chloride is a salt and will exist in the cationic form in the environment. Based on a classification scheme(1), Kd values of 9.88 to 25.0(2), and Koc values ranging from 67 to 4685(3) indicate that mepiquat chloride is generally expected to adsorb to suspended solids and sediment(SRC). Dissociated mepiquat chloride will not volatilize from water surfaces. Based on a guideline study, mepiquat chloride is not expected to accumulate in fish(2). Neither hydrolysis or photolysis are expected to be important fate processes, baed upon protocol studies(2). Biodegradation data for mepiquat chloride in water are not available; however, it is fairly rapidly biodegraded to carbon dioxide in soil studies (half-lives of 3 to 21 days). Mepiquat chloride is resistant to anaerobic biodegradation(2).|ATMOSPHERIC FATE: Mepiquat chloride is a salt and will not volatilize. Particulate-phase mepiquat chloride may be removed from the air by wet and dry deposition. (SRC)

Less than 10% degradation at pH values of 3 to 9 was reported in a standardized hydrolysis test (USEPA guideline 161-1)(2). In a standardized aqueous photolysis test (USEPA guideline 161-2), mepiquat chloride was found to be stable to photolysis with recovery of the parent compound >95% at the end of the study(2).

Mepiquat chloride is a salt and will exist as the cation in the environment. Based on a guideline study, mepiquat chloride is not expected to accumulate in fish(1).

1.00e+06 L/kg|This compound, a salt, will exist in the dissociated form in the environment. Kd values of 9.88, 12.0, and 25.0, were reported for sandy loam, loam, and clay soils, respectively(1). A Kd of 0.22 was measured in sand(1). Koc values ranging from 67 to 4685 have also been reported(2). According to a classification scheme(3), these values suggest that mepiquat chloride is expected to have slight mobility in most soils although it may have high mobility in sand soils.

This compound, a salt, will exist in the dissociated form in the environment and therefore volatilization from moist soil and water surfaces is not expected to be an important fate process(SRC). Mepiquat chloride is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of <2.3X10-6 mm Hg(1).

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

In a metabolism study, mepiquat chloride, labeled with 14C in the 2,6-carbon atoms of the ring structure (radiochemical purity: 98%), was administered to young adult Sprague-Dawley rats (5/sex/group) either iv or orally. During the study, the rats received a standard diet (pellets) as follows: for body weight 150 g: 10% of body weight + 3 g; for body weight 150 g, 10% of body weight + 2 g. Water was provided ad libitum. Mepiquat chloride was absorbed rapidly from the stomach, distributed evenly in the intra and extracellular compartments of the blood, demonstrated high bioavailability via the oral route, was excreted mostly in urine, and did not accumulate in tissues. Other excretions of the administered radioactivity were as follows: feces, 2-15%; exhaled air, (14CO2 ), 0.20%; and bile, 0.23-0.31%. The bioavailability of mepiquat chloride appears to depend on the presence of food in the GI tract. In the two male rats used in the study of pulmonary elimination of mepiquat chloride as C-volatiles, which had access to food immediately after dosing, the bioavailability was much lower (58%) than that of a similar treatment group in which food was withheld until 4 hours after dosing (79%). Mepiquat chloride did not accumulate in tissues.|In a metabolism study, mepiquat chloride, labeled with 14C in the 2,6-carbon atoms of the ring structure (radiochemical purity: 98%), was administered to young adult Sprague-Dawley rats (5/sex/group) either iv or orally. ... Urine, feces and bile samples from various treatments were used for studies of the metabolic fate of mepiquat chloride. In all cases, only the unchanged compound could be detected. Therefore, there was no biotransformation of mepiquat chloride in vivo. The potential metabolites, such as 1-methylpiperidine or piperidine, were not detected.|The plant growth regulators chlormequat and/or mepiquat were investigated in cereals from the Danish harvest of 1999 where 83% of the samples contained chlormequat (n = 46) compared with 87% of the samples from the 1997 harvest (n = 52). The average concentration of chlormequat in 1999 was 0.32 mg/kg compared with 0.23 mg/kg in 1997. At 2.9 mg/kg, one sample of wheat bran was exceeding the MRL of 2 mg/kg for wheat. The intakes of the pesticides through the diet of cereals were estimated to comprise 1% of the ADI for chlormequat for an adult Dane.

Basic treatment: Establish a patent airway. 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 normal saline 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... . /Poison A and B/|Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in respiratory arrest. Positive pressure ventilation techniques with a bag valve mask device may be beneficial. Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start an IV with D5W /SRP: "To keep open", minimal flow rate/. Use lactated Ringer's if signs of hypovolemia are present. Watch for signs of fluid overload. Consider drug therapy for pulmonary edema ... . For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam (Valium) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poison A and B/

1,1-dimethylpipercl

77% of all mepiquat chloride consumed (1993-1995) in the United States was applied in the states of Texas, Mississippi, California, Arkansas, Louisiana and North Carolina.

Aqueous solution, soluble concentrate or ulta low volume concentrate.|USEPA/OPP Pesticide Code 109101; Trade Names: Pix; BAS 083 01 W; Terpal, component of (with 099801); Pix DF.|Trade names: Pix (BASF); mepiquat mixed with ethephon: Terpal (BASF).

Pesticide, fertilizer, and other agricultural chemical manufacturing|Piperidinium, 1,1-dimethyl-, chloride (1:1): ACTIVE|PMN - indicates a commenced PMN (Pre-Manufacture Notices) substance.