1,1-Dimethylpiperidiniumchlorid

Pesticide -> EPA IRIS

Pesticides -> Plant Growth Regulators

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

Bulk density = 0.421 g/ml

Solubility in ethanol 162, chloroform 10.5, benzene, ethyl acetate, cyclohexane all <1.0 (all in g/kg at 20 °C)

Solubility in octanol - 0.95 g/100 ml; water - 52.9 g/100 ml; methanol - 5 g/100 ml

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

Danger

H301: Toxic if swallowed [Danger Acute toxicity, oral]

P261, P264, P270, P271, P273, P301+P316, P304+P340, P317, P321, P330, P405, and P501 (click each P-code to see the statement)

Warning

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

P261, P264, P270, P271, P273, P301+P317, P304+P340, P317, P330, and P501 (click each P-code to see the statement)

Chemical: Piperidinium, 1,1-dimethyl-, chloride

Commission Regulation (EC) No 1490/2002

PMN - indicates a commenced PMN (Pre-Manufacture Notices) substance.

Mepiquat Chloride is listed in the dataset of EPA Human Health Benchmarks for Pesticides under the Safe Drinking Water Act (40 eCFR 141)

Mepiquat chloride: Does not have an individual approval but may be used as a component in a product covered by a group standard. It is not approved for use as a chemical in its own right.

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]

Tolerances are established for residues of the plant growth regulator mepiquat (N,N-dimethylpiperidinium) in or on the following commodities: cattle, meat byproducts; cotton, gin byproducts; cottonseed; goat, meat byproducts; hog, meat byproducts; horse, meat byproducts; sheep, meat byproducts.

Tolerances are established for residues of the plant growth regulator mepiquat chloride (N,N-dimethylpiperidinium chloride) in or on the following commodities: cattle, fat; cattle, meat; goat, fat; goat, meat; grape; hog, fat; hog, meat; horse, fat; horse, meat; raisins; sheep, fat; sheep, meat.

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA '88 were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern and List D pesticides of less concern. Mepiquat chloride is found on List B. Case No: 2375; Pesticide type: herbicide; Case Status: RED Approved 9/96; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): N,N-dimethylpiperidinium chloride; Data Call-in (DCI) Date(s): 4/5/91, 1/10/94, 10/13/95; AI Status: RED Completed - OPP has completed a Reregistration Eligibility Decision (RED) document for the case/AI.

Acute Tox. 4 (100%)

Acute toxicity - category 4

Acute Tox. 3

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.

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.

Tolerances are established for residues of the plant growth regulator mepiquat (N,N-dimethylpiperidinium) in or on the following commodities: cattle, meat byproducts, 0.1 ppm; cotton, gin byproducts, 6.0 ppm; cottonseed, 2.0 ppm; goat, meat byproducts, 0.1 ppm; hog, meat byproducts, 0.1 ppm; horse, meat byproducts, 0.1 ppm; sheep, meat byproducts, 0.1 ppm. /Mepiquat/

Tolerances are established for residues of the plant growth regulator mepiquat chloride (N,N-dimethylpiperidinium chloride) in or on the following commodities: cattle, fat, 0.1 ppm; cattle, meat, 0.1 ppm; goat, fat, 0.1 ppm; goat, meat, 0.1 ppm; grape, 1.0 ppm; hog, fat, 0.1 ppm; hog, meat, 0.1 ppm; horse, fat, 0.1 ppm; horse, meat, 0.1 ppm; rasisins, 5.0 ppm; sheep, fat, 0.1 ppm; sheep, meat, 0.1 ppm.

LC50 Trout 4,300 mg/l/96 hr /Conditions of bioassay not specified/

EC50 Daphnia 68.5 mg/l/48 hr /Conditions of bioassay not specified/

LD50 Northern bobwhite quail (Colinus virginianus) >2,000mg/kg

LC50 /EC50, Eastern oyster (shell deposition or embryo larvae) (Crassostrea virginica) 12.6 ppm/96 hr (as a.i.; 54.6%) measured, flowthrough

LC50/EC50 Mysid (Americamysis bahia) >136 ppm/96 hr (as a.i; 54.6%) measured, static

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)

/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

Hematologic

3 x 10 ^-2 mg/kg-day

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.

Mepiquat chloride is fairly rapidly degraded in aerobic soil, at an initial concentration of 1 mg/l, to carbon dioxide with half- lives of 3 to 21 days for this process(1). In bare ground field studies (for cotton use) conducted in Mississippi, Texas, and California, half-lives of 3, 21, and 17 days, respectively, were reported(1). Bare ground field studies at higher application rates(for vineyard use) conducted in New York, Washington, and California provided half-lives of 6.5 to 87.2 days for the three sites(1). This compound is resistant to biodegradation under anaerobic conditions(1).

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).

Tolerances are established for residues of the plant growth regulator mepiquat (N,N-dimethylpiperidinium) in or on the following commodities: cattle, meat byproducts; cotton, gin byproducts; cottonseed; goat, meat byproducts; hog, meat byproducts; horse, meat byproducts; sheep, meat byproducts.

Tolerances are established for residues of the plant growth regulator mepiquat chloride (N,N-dimethylpiperidinium chloride) in or on the following commodities: cattle, fat; cattle, meat; goat, fat; goat, meat; grape; hog, fat; hog, meat; horse, fat; horse, meat; raisins; sheep, fat; sheep, meat.

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA '88 were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern and List D pesticides of less concern. Mepiquat chloride is found on List B. Case No: 2375; Pesticide type: herbicide; Case Status: RED Approved 9/96; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): N,N-dimethylpiperidinium chloride; Data Call-in (DCI) Date(s): 4/5/91, 1/10/94, 10/13/95; AI Status: RED Completed - OPP has completed a Reregistration Eligibility Decision (RED) document for the case/AI.

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.

Used as plant growth regulator; [Merck Index] Used exclusively on cotton to inhibit synthesis of gibberellic acid, a plant hormone; [Reference #1]

Farming (Pesticides) [Category: Industry]

Major use as a plant growth regulator for cotton.

Used on cotton to reduce vegetative growth & advance maturation of the bolls: & to inhibit sprouting in onions, garlic, and leeks. Used in combination with ethephon to prevent lodging (by shortening the stem & strengthening the stem wall) in cereals, grass seed crops, & flax.

For mepiquat chloride (USEPA/OPP Pesticide Code: 109101) ACTIVE products with label matches. /SRP: Registered for use in the U.S. but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./

This is a man-made compound that is used as a pesticide.

... Produced from N-methylpiperidine and chloromethane.

Prepn: B. Zeeh et al., DE 2207575; B. Zeeh et al., US 3905798 (1973, 1975 both to BASF).

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).