Dimethomorph

Agrochemicals -> Pesticide active substances

Active substance -> EU Pesticides database: Not approved

Pesticides -> Fungicides

Fungicides

Pesticide (Dimethomorph) -> USDA PDB

Pesticide

In water (mg/L at 20 °C): 81.1 at pH 4; 49.2 at pH 7; 41.8 at pH 9

Solubility (g/L at 20 deg ): acetone 50; toluene 20; methanol 20; dichloromethane 500

Solubility in n-hexane 0.11; methanol 39; ethyl acetate 48.3; toluene 49.5; acetone 100; dichloromethane (all for E,Z, in g/L)

Solubility of z-isomer (g/L, 20-23 °C): acetone, 16.3; cyclohexanone, 27; dichloromethane, 315; dimethylformamide, 165; n-hexane, 0.036; methanol, 7.5; toluene, 10.5' ethyl acetate 8.4. Solublity of e-isomer: In acetone, 84.1; dimethylformamide, 272; n-hexane, 0.076; toluene 39.0; dichloromethane 296; ethyl acetate 39.9; methanol 31.5

127-148 °C

MP: 125-149 °C

0.00000001 [mmHg]

Vapor pressure: (E)-isomer 9.7X10-4 mPa; (Z) isomer 1.0X10-3 mPa (both at 25 °C)

7.39X10-6 mm Hg at 25 °C

Danger

H360F: May damage fertility [Danger Reproductive toxicity]

P203, P273, P280, P318, P391, P405, and P501 (click each P-code to see the statement)

Danger

H360F (40.8%): May damage fertility [Danger Reproductive toxicity]

P203, P273, P280, P318, P391, P405, and P501 (click each P-code to see the statement)

Hazard Traits - Reproductive Toxicity

Commission Regulation (EC) No 451/2000

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

07/25/EC, Reg. (EU) 2018/917, Reg. (EU) 2019/707, Reg. (EU) 2020/869, Reg. (EU) 2021/745, Reg. (EU) 2022/708, Reg. (EU) 2023/918, Reg. (EU) 2024/1207, Reg. (EU) No 540/2011

Status: No longer Valid Update: 15-12-2008 https://echa.europa.eu/registration-dossier/-/registered-dossier/8445

Dimethomorph: 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 Prevention, Pesticides and Toxic Substances, Pesticide Fact Sheet for Dimethomorph, Reason for Issuance: New Pesticide Registration (September 30, 1998).[Available from, as of October 11, 2012: http://iaspub.epa.gov/apex/pesticides/f?p=CHEMICALSEARCH:1]

Tolerances are established for the residues of the fungicide dimethomorph, (E,Z) 4-[3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl)-1-oxo-2-propenyl]morpholine, in or on the following commodities:[Table#6455]

Tolerances with regional registrations are established for residues of the fungicide dimethomorph, (E,Z) 4-[3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl)-1-oxo-2-propenyl]morpholine, in or on the following commodity: Bean, lima, succulent.

Tolerances are established for the indirect or inadvertent residues of the fungicide dimethomorph, in or on the commodities in the following table. Compliance with the following tolerance levels specified in the following table is to be determined by measuring only dimethomorph (E,Z)-4-[3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl)acryloyl]morpholine calculated in or on the following commodities:[Table#6456]

Aquatic Chronic 1 (100%)

Repr. 1B (40.8%)

Reproductive toxicity - category 1B

Hazardous to the aquatic environment (Acute) - Category 2

Reproductive toxicity - Category 1B

Repr. 1B

Store in secure, well ventilated building away from food and feed and out of reach of children.

Do not contaminate water, food or feed by storage or disposal. ... Store in a cool, well-ventilated area. Do not allow to become overheated in storage. Keep container closed when not in use. /Acrobat 50WP Fungicide/

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.

Container Disposal: Completely empty bag into application equipment. Then dispose of empty bag in a sanitary landfill or by incineration, or, if allowed by State and local authorities, by buming. If burned, stay out of smoke. /Acrobat 50WP Fungicide/

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

Avoid contact with skin, eyes, nose, and mouth. Wash all exposed skin before eating, drinking, smoking, or using the toilet.

Avoid raising a dust cloud. Fine dust clouds may be explosive mixtures with air.

Use this product only in accordance with its labeling and with the Worker Protection Standard. 40 CFR part 170. /Acrobat 50WP Fungicide/

Do not apply directly to water to areas where surface water is present or to intertidal areas below the mean high water mark. /Acrobat 50WP Fungicide/

For more Preventive Measures (Complete) data for DIMETHOMORPH (9 total), please visit the HSDB record page.

Tolerances are established for the residues of the fungicide dimethomorph, (E,Z) 4-[3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl)-1-oxo-2-propenyl]morpholine, in or on the following commodities:[Table#6453]

Tolerances with regional registrations are established for residues of the fungicide dimethomorph, (E,Z) 4-[3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl)-1-oxo-2-propenyl]morpholine, in or on the following commodities: Bean, lima, succulent, 0.60 ppm.

Tolerances are established for the indirect or inadvertent residues of the fungicide dimethomorph, in or on the commodities in the following table. Compliance with the following tolerance levels specified in the following table is to be determined by measuring only dimethomorph (E,Z)-4-[3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl)acryloyl]morpholine calculated in or on the following commodities:[Table#6454]

Chemical-resistant gloves. Long-sleeved shirt and long pants. Protective eyewear. Waterproof boots and hat.

Applicators and other handlers must wear: long-sleeved shirt and long pants; chemical resistant gloves made of any waterproof material, such as polyethylene or polyvinyl chloride; shoes plus socks. /Acrobat 50WP Fungicide/

Restricted entry interval (REI) of 12 hours. For early entry to treated areas that is permitted under the Worker Protection Standard and that involves contact with anything that has been treated, such as plants, soil or water, wear: coveralls; chemical resistant gloves made of any waterproof material, such as polyethylene or polyvinyl chloride; shoes plus socks. /Acrobat 50WP Fungicide/

LC50; Species: Colinus virginianus (Northern Bobwhite Quail) diet >5300 ppm for 8 days

LD50; Species: Colinus virginianus (Northern Bobwhite Quail) oral >2000 mg/kg bw /96.6% a.i./ /from table/

LC50; Species: Anas platyrhynchos (Mallard Duck) diet >5300 ppm for 8 days

LD50; Species: Anas platyrhynchos (Mallard Duck) oral via capsule >2000 mg/kg

For more Ecotoxicity Values (Complete) data for DIMETHOMORPH (8 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 5690(SRC), determined from a structure estimation method(2), indicates that dimethomorph is expected to be immobile in soil(SRC). Volatilization of dimethomorph from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.0X10-15 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Dimethomorph is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 7.39X10-9 mm Hg at 25 °C(4). Biodegradation data in soil were not available(SRC,2012).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 5690(SRC), determined from a structure estimation method(2), indicates that dimethomorph is 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 1.0X10-15 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of 27(SRC), from its log Kow of 2.68(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Dimethomorph is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(6). Biodegradation data in water were not available(SRC, 2012).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dimethomorph, which has a vapor pressure of 7.39X10-9 mm Hg at 25 °C(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase dimethomorph may be removed from the air by wet or dry deposition(SRC). Dimethomorph contains chromophores that absorb at wavelengths >290 nm(3) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of dimethomorph can be estimated to be 5690(SRC). According to a classification scheme(2), this estimated Koc value suggests that dimethomorph is expected to be immobile in soil.

/ENDOCRINE MODULATION/ We tested a combination of 8 AR antagonists that did not also possess AR agonist properties ("pure" antagonists; 8 mix: fludioxonil, fenhexamid, ortho-phenylphenol, imazalil, tebuconazole, dimethomorph, methiocarb, pirimiphos-methyl), a combination of 5 AR antagonists that also showed agonist activity (5 mix: cyprodinil, pyrimethanil, vinclozolin, chlorpropham, linuron), and all pesticides combined (13 mix) using the MDA-kb2 assay. Concentration addition (CA) and independent action (IA) were used to formulate additivity expectations and Schild-plot analyses were conducted to investigate competitive AR antagonism. Results: A good agreement between the effects of the mixture of 8 "pure" AR antagonists and the responses predicted by CA was observed. Schild plot analysis revealed that the 8 mix acted by competitive AR antagonism. However, the observed responses of the 5mix and the 13 mix fell between the prediction window defined by CA and IA. Schild plot analysis with these mixtures yielded anomalous responses incompatible with competitive receptor antagonism. ... /It was reported/ that a mixture of widely used pesticides can produce combined AR antagonist effects that exceed the responses elicited by the most potent component alone in a predictable manner.

/ENDOCRINE MODULATION/ /Investigators/ used estimated human exposure data to select pesticides to test for antiandrogenic activity, focusing on highest use pesticides. European databases /were used/ to select 134 candidate pesticides based on highest exposure, followed by a filtering step according to known or predicted receptor-mediated antiandrogenic potency, based on a previously published quantitative structure-activity relationship (QSAR) model. In total, 37 pesticides were tested for in vitro androgen receptor (AR) antagonism. Of these, 14 were previously reported to be AR antagonists ("active"), 4 were predicted AR antagonists using the QSAR, 6 were predicted to not be AR antagonists ("inactive"), and 13 had unknown activity, which were "out of domain" and therefore could not be classified with the QSAR ("unknown"). All 14 pesticides with previous evidence of AR antagonism were confirmed as antiandrogenic in our assay, and 9 previously untested pesticides were identified as antiandrogenic (dimethomorph, fenhexamid, quinoxyfen, cyprodinil, lamda-cyhalothrin, pyrimethanil, fludioxonil, azinphos-methyl, pirimiphos-methyl). In addition, we classified 7 compounds as androgenic.

/GENOTOXICITY/ Peripheral human lymphocytes in whole blood from a healthy male volunteer were cultured for 48 hr (0.4 mL blood in 5 mL medium) prior to exposure to test article (98.6% dimethomorph), -/+ S9, for 2 hr followed by incubation for 21-23 hr or for 45-47 hr. Cell division was arrested during the last 3 hr by 0.5 mg/mL colchicine and chromosome spreads were produced for analysis. Doses, based on 2 cytotoxicity screens for inhibition of mitotic index (with the total # of cells with aberrations (-gaps) per 200 metaphases expressed in parentheses) were 0 (0), 10 (1), 100 (2) and 333 (2) ug/mL (24-hr fixation) and 0 (6), 333 (2) and 422 (17) ug/mL (48-hr fixation) in the absence of S9, and 0 (2), 1 (3), 10 (3), 333 (0) and 422 (48; p<0.001) ug/mL (24-hr fixation) and 0 (1) and 422 (3) ug/mL (48-hr fixation). Duplicate cultures were used. 100 metaphase spreads/culture were examined for aberrations. The results indicate that the number of aberrations increases at 422 mg/mL in both the absence and presence of S9. Most of the increase is associated with chromatid or chromosome breaks, or chromosome exchanges. The increase may be associated with high toxicity (expressed as an inhibition of mitotic index greater than 50% compared to controls) in those experiments in which a rise in chromosome aberrations is detected. The evidence suggests that dimethomorph is clastogenic in this system, at least in the presence of high toxicity.

An estimated BCF of 27 was calculated in fish for dimethomorph(SRC), using a log Kow of 2.68(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 Henry's Law constant for dimethomorph is estimated as 1.0X10-15 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that dimethomorph is expected to be essentially nonvolatile from water and moist soil surfaces(2). Dimethomorph is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 7.39X10-9 mm Hg(3).

/LABORATORY ANIMALS: Acute Exposure/ The dermal sensitization potential of dimethomorph (purity, 98.0%) was investigated in male Crl (HA)BR guinea-pigs via the maximization test of Magnusson and Kligman. In two pre-test studies, four males received 0.1 mL of dimethomorph intradermally at a concentration of 1%, 5%, 10%, 15%, and 25% in mineral oil and another four males received dimethomorph topically at a concentration of 1%, 5%, 10%, and 25% in petrolatum occluded for 24 hr by patches. All guinea-pigs in both groups received all doses and were evaluated for skin irritation 24 hr and 48 hr after application. In the group treated by intradermal injection, all doses induced dose-dependent skin irritations that were moderate-intense at 5%. In the group treated by topical application, no irritation was observed at any dose. For the main study, the concentrations of 5% for intradermal injection and 25% for topical application were selected. Twenty males were induced intradermally with 5% dimethomorph in mineral oil and Freund complete adjuvant and then on day 9 topically with 25% dimethomorph in petrolatum. On day 23, the guinea-pigs were challenged by topical application of 25% dimethomorph in petrolatum. The negative-control group consisted of 20 males. ... No skin irritation was recorded in any of the challenged or control guinea-pigs. Dimethomorph had no skin sensitization potential /under the conditions assayed/.

/LABORATORY ANIMALS: Acute Exposure/ The dermal and ocular irritation potential of dimethomorph was investigated in New Zealand White (NZW) rabbits. The test compound was dimethomorph (purity, 98.5%; E :Z, 46:54). For dermal irritation, three rabbits (two males, one female) were exposed to 500 mg of test compound for 4 hr under semi-occlusive conditions and observed for another 72 hr after removal. For ocular irritation, three animals (one male, two females) were given 50 mg of test compound in a volume of 0.1 mL into the conjunctival sac of one eye. The eyes were not rinsed. ... In the test for dermal irritation, no signs of an irritating potential were recorded. In the test for ocular irritation, all rabbits showed reddened conjunctivae and slight chemosis. These signs resolved within 4 hr after dosing.

/LABORATORY ANIMALS: Acute Exposure/ Groups of five male and five female Wistar rats were exposed by inhalation to dimethomorph Z-isomer (purity, 98.7%) at a concentration of 4.24 mg/L (the highest concentration attainable) in a whole-body chamber for 4 hr. 56% of particles had a mean aerodynamic diameter of 5.5 um or less. Animals were then observed for 14 consecutive days. ... All rats survived till study termination. During the exposure, the rats showed changes in posture and respiratory patterns. Noticeable breathing was resolved after 5 days. Within the first 2-3 days, reduced feed intake and reduced body-weight gain was found. Therefore, the median lethal concentration (LC50) of the Z-isomer was greater than 4.24 mg/L for males and females. /Z-Isomer/

/LABORATORY ANIMALS: Acute Exposure/ Dermal toxicity was investigated in a study /with/ Fischer 344 rats. Groups of five males and five females exposed dermally to dimethomorph (purity, 98.5%; E :Z, 46:54) at a dose of 2000 mg/kg bw for 24 hr and then observed for 14 days. ... No signs of toxicity and no mortalities were observed. Therefore, the LD50 was greater than 2000 mg/kg bw in males and females.

For more Non-Human Toxicity Excerpts (Complete) data for DIMETHOMORPH (33 total), please visit the HSDB record page.

Tolerances are established for the residues of the fungicide dimethomorph, (E,Z) 4-[3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl)-1-oxo-2-propenyl]morpholine, in or on the following commodities:[Table#6455]

Tolerances with regional registrations are established for residues of the fungicide dimethomorph, (E,Z) 4-[3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl)-1-oxo-2-propenyl]morpholine, in or on the following commodity: Bean, lima, succulent.

Tolerances are established for the indirect or inadvertent residues of the fungicide dimethomorph, in or on the commodities in the following table. Compliance with the following tolerance levels specified in the following table is to be determined by measuring only dimethomorph (E,Z)-4-[3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl)acryloyl]morpholine calculated in or on the following commodities:[Table#6456]

Systemic fungicide with good protectant, curative and antisporulant activity. Inhibits the formation of the oomycete fungal cell wall. Only the Z-isomer is intrinsically active, but, because of rapid interconversion of isomers in the light, it has no advantage over the E-isomer in practice.

Rat Oral administration of dimethomorph (10 mg/kg single dose; 10 mg/kg 14-day repeated dose; 10 mg/kg 7-day repeated dose; 500 mg/kg single dose) results in rapid excretion into the urine and feces of rats. ...Biliary excretion exhibited first-order kinetics with a lowdose (10 mg/kg) half-life of approximately three hours and a high-dose (500 mg/kg) half-life of 11 hours for males and about 6 hours for females.

Rat Oral administration of dimethomorph (10 mg/kg single dose; 10 mg/kg 14-day repeated dose; 10 mg/kg 7-day repeated dose; 500 mg/kg single dose) results in rapid excretion into the urine and feces of rats. ... Urinary metabolites resulted from demethylation of the dimethoxyphenyl ring and oxidation of the morpholine ring. ...Biliary metabolites accounted for most of the fecal excretion following low-dose treatment. The major biliary metabolites were glucuronides of one and possibly two of the compounds produced by demethylation of the dimethoxyphenyl ring. The report provided a proposed metabolic pathway for dimethomorph.

In rats, the major route of metabolism is demethylation of one of the dimethoxy groups or by oxidation of one of the CH2 groups (ortho- or meta-position) of the morpholine ring.

Rat Oral administration of dimethomorph (10 mg/kg single dose; 10 mg/kg 14-day repeated dose; 10 mg/kg 7-day repeated dose; 500 mg/kg single dose) results in rapid excretion into the urine and feces of rats. For all treatment protocols, most (80-90%) of the radiolabel administered was excreted in the feces. A considerably smaller amount (6-16%) was excreted in the urine and only minimal levels (0.1-0.4%) were detected in the organs and tissues. Rapid absorption may be inferred by the rapid excretion of metabolites in the urine and bile. Saturation of absorption following single high doses (500 mg/kg) was indicated by large amounts (50%) of radioactivity in the feces being associated with parent compound. For low- or highdose treatment, urinary excretion in female rats tended to be greater (up to 2-fold in low-dose rats) than that of male rats. Retention of dimethomorph or (14)C-dimethomorph-derived radioactivity was generally 1% for most tissues although the liver exhibited slightly higher levels (1.4%) and higher levels in the gastrointestinal tract organs were due to radioactivity in the lumenal contents.

Used as agricultural fungicide; [Merck Index] Used as a systemic fungicide on potatoes; [Reference #1]

Farming (Pesticides) [Category: Industry]

For dimethomorph (USEPA/OPP Pesticide Code: 268800) 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./

Fungicide effective against Oomycetes, especially Peronosporaceae and Phytophthora spp. (but not Pythium spp.) in vines, potatoes and tomatoes. Used in combination with contact fungicides.

Fungicide

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

Dimethomorph is produced by Friedel-Crafts acylation of 1,2-dimethoxybenzene with 4-chlorobenzoyl chloride, followed by condensation with triethyl phosphonoacetate in the presence of a base such as sodium hydride in dimethoxyethane. The resulting ethyl cinnamate is then converted to the correspondingmorpholide.

Premix Partners: Ametoctradin; Chlorothalonil; Copper sulfate, tribasic; Folpet; Mancozeb.

Dispersible concentrate; suspension concentrate, wettable powder.

Composition: (E) isomer to (Z) isomer ratio is 1:1.

Acrobat(R) Fungicide Technical (BASF Corporation), Dimethomorph 98.98%.

For more Formulations/Preparations (Complete) data for DIMETHOMORPH (15 total), please visit the HSDB record page.

The WHO Recommended Classification of Pesticides by Hazard identifies dimethomorph (technical grade) as Class III: slightly hazardous; Main Use: fungicide, other than for seed treatment.

Fungicidal activity is primarily associated with the Z isomer.

Only the (Z)- isomer is intrinsically active, but, because of rapid interconversion of isomers in the light, it has no advantage over the (E)-isomer in practice.

Composition: (E) isomer to (Z) isomer ratio is 1:1.