시듀론

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 POTW is acceptable only after review by the governing authority. 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 meet Hazardous Material Criteria for disposal.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure 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, aquatic, and plant life; and conformance with environmental and public health regulations.

Do not discharge effluent containing this product into lakes, streams, ponds, estuaries, oceans, or other waters unless in accordance with the requirements of a National Pollution Discharge Elimination System (NPDES) permit and the permitting authority has been notified in writing prior to discharge.

Burning: Small quantities of siduron should be burned and large quantities incinerated in a unit operting at 850 °C equipped with off gas scrubbing equipment. Recommendable method: Incineration. Not recommendable method: Hydrolysis. Peer review: Hydrolysis generates dimethylamine and aniline. (Peer- review conclusions of an IRPTC expert consultation (MAY 1985))

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. Quality assurance to ascertain the completeness of the cleaning procedures should be implemented before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at end of shift, but should remain at employee's place of work for cleaning.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

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.

Avoid breating dust or spray mist. Avoid contact with skin, eyes, and clothing.

For more Preventive Measures (Complete) data for SIDURON (15 total), please visit the HSDB record page.

All mixers, loaders, applicators and other handlers must wear: Long-sleeve shirt and long pants, Chemical-resistant gloves, Shoes plus socks. In addition, for chemigation: All mixers and loaders must wear: NIOSH-approved dust/mist filtering respirator with MSHA/NIOSH approval number prefix TC-21C or a NIOSH-approved respirator with any N, R, P, or HE filter.

LC50; Species: Anas platyrhynchos (Mallard duckling) diet >10,000 mg/kg for 8 day

LC50; Species: Colinus virginianus (Northern bobwhite, age 10 days) diet >5620 ppm for 8 days

LC50; Species: Colinus virginianus (Bobwhite quail) oral >10,000 mg/kg diet for 8 days

LD50; Species: Apis mellifera (Honey bee, worker) topical 120 ug/bee for 48 hr

For more Ecotoxicity Values (Complete) data for SIDURON (14 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), estimated Koc values from 330(SRC) determined from a log Kow of 3.80(3) and a structure estimation method(4) to 420(2), indicate that siduron is expected to have moderate mobility in soil(SRC). Volatilization of siduron from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 6.8X10-11 atm-cu m/mole(SRC) derived from its vapor pressure, 4.0X10-9(2), and water solubility, 18 mg/L(5). Siduron is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 4.0X10-9 mm Hg at 25 °C(2). Siduron is expected to undergo microbial degradation in soil with half-lives ranging from 90-150 days(3,6). Siduron is not expected to be decomposed by sunlight(3).

TERRESTRIAL FATE: No siduron metabolites were detected in barley after an 8-day adsorption period.

AQUATIC FATE: Based on a classification scheme(1), estimated Koc values from 330(SRC), determined from a log Kow of 3.80(3) and a structure estimation method(4), to 420(2) indicate that siduron may be expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(5) based upon an estimated Henry's Law constant of 6.8X10-11 atm-cu m/mole(6), derived from its vapor pressure, 4.0X10-9 mm Hg(2), and water solubility, 18 mg/L(7). According to a classification scheme(8), an estimated BCF of 150(SRC), from its log Kow and a regression-derived equation(9), suggests the potential for bioconcentration in aquatic organisms is high(SRC). Siduron is expected to undergo microbial degradation in water with a half-life ranging from 120-150 days(3). Hydrolysis may occur under acidic or alkaline conditions(10).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), siduron, which has a vapor pressure of 4.0X10-9 mm Hg at 25 °C(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase siduron may be removed from the air by wet or dry deposition(SRC). Siduron does not contain chromophores that absorb at wavelengths >290 nm(4) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

/AQUATIC SPECIES/ Substituted ureas and carbamates are mechanistic inhibitors of the soluble epoxide hydrolase (sEH). ... A set of chemicals containing these functionalities /were screened/ in larval fathead minnow (Pimphales promelas) and embryo/larval golden medaka (Oryzias latipes) models to evaluate the utility of these systems for investigating sEH inhibition in vivo. ... Low lethality was observed in either larval or embryonic fish exposed to diuron [N-(3,4-dichlorophenyl), N'-dimethyl urea], desmethyl diuron [N-(3,4-dichlorophenyl), N'-methyl urea], or siduron [N-(1-methylcyclohexyl), N'-phenyl urea]. Dose-dependent inhibition of sEH was a sublethal effect of substituted urea exposure with the potency of siduron < desmethyl diuron = diuron, differing from the observed in vitro sEH inhibition potency of siduron > desmethyl diuron > diuron. Further, siduron exposure synergized the toxicity of trans-stilbene oxide in fathead minnows. Medaka embryos exposed to diuron, desmethyl diuron, or siduron displayed dose-dependent delays in hatch, and elevated concentrations of diuron and desmethyl diuron produced developmental toxicity...

/PLANTS/ Bermuda grass and certain bent grasses may be injured when applied pre-emergence.

The Koc of siduron is predicted in one study to be 420(1). Using a log Kow of 3.80(2) and a structure estimation method based on molecular connectivity indices(3), the Koc is estimated as 330(SRC). According to a classification scheme(4), these Koc values suggest that siduron is expected to have moderate mobility in soil. A Pesticide Leaching Potential (PLP) Index of 53 for foliar application and 57 for soil application was calculated for siduron using commonly reported Koc, persistence (half-life), and rate of application values(5,6). PLP values of 0 and 100 indicate no leaching potential and maximum leaching potential, respectively(6). Siduron was classified as having low mobility using retention factors from soil TLC using Hagerstown silty clay loam soil plates(7).

Adsorption increases as clay or organic matter content increases, and as cation exchange capacity of clay increases. The amount adsorbed on Keyport silt loam in equilibrium with 1 ppm in soil solution at 22.5 °C is 2.5 ppm (average Koc is 420 mL/g). Siduron is moderately resistant to leaching. Movement is least in soils high in clay or organic matter and greatest in sand.

/SURVEILLANCE/ The OPP Incident Data System (IDS) listed ... reported incidents involving siduron submitted to OPP since 1992. One individual reported weakness, headache, and dizziness two hours after applying a siduron product, and this person was treated in an emergency room.

/SURVEILLANCE/ The OPP Incident Data System (IDS) listed ... reported incidents involving siduron submitted to OPP since 1992 ... an individual inhaled the product and reported nausea, loss of hand coordination, difficulty breathing, and slurred speech.

/SURVEILLANCE/ ...The National Poison Control Centers (PCC) /reported/ between 1993 and 2003: one case in the Occupational Class involving moderate symptoms of abdominal pain and bronchospasm; nine cases in the Non-Occupational Class were reported, but only one presented mild symptoms; and twenty-five cases were suspected of exposure in the Children's Group, where nine were followed and presented no symptoms.

/SURVEILLANCE/ One incident was reported to the California Department of Pesticide Regulation since 1982, where a grower applied the product by sprinkler irrigation and reported a red and painful left eye and blurred vision.

/GENOTOXICITY/ INZ1318-70 (Lot No. A060588-31, 6-88; purity = 99.9%), dissolved in DMSO; human lymphocytes cultured from a male and female donor were treated with 0 (DMSO), 0.01, 0.06, 0.10, and 0.12 mg/mL for 3 hr, with and without activation (Aroclor 1254-induced rat liver S9 fraction); two replicate cultures/dose level were tested with appropriate vehicle and positive (MMC, CP) controls; two trials; 100 metaphases/treatment level were examined; no adverse effects; no significant increases in frequency of chromosomal aberrations were observed; positive controls were functional.

AEROBIC: Microbial degradation has been reported to occur in soil using C14-labeled siduron(1). In water and soil, microbial degradation has been reported to occur with a half-life of approximately 120-150 days(2). Siduron has a measured field half-life of 90 days(3).

/Siduron is/ subject to microbial decomp under moist conditions in soil.

Primarily degraded by microbes. Certain soil microbes can utilize siduron as a sole carbon source. Two bacterial and one fungal species capable of metabolizing siduron have been isolated.

An estimated BCF of 150 was calculated in fish for siduron(SRC), using a log Kow of 3.80(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is high(SRC), provided the compound is not metabolized by the organism(SRC).

The Henry's Law constant for siduron is estimated as 6.8X10-11 atm-cu m/mole(SRC) derived from its vapor pressure, 4.0X10-9 mm Hg(1), and water solubility, 18 mg/L(2). This Henry's Law constant indicates that siduron is expected to be essentially nonvolatile from water(3) and moist soil surfaces(SRC). Siduron is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure of 4.0X10-9 mm Hg(1).

/LABORATORY ANIMALS: Acute Exposure/ In percutaneous tests on rabbits 5500 mg/kg (max feasible dose) applied to their intact or abraded skin caused no sign of toxicity.

/LABORATORY ANIMALS: Acute Exposure/ In skin tests with guinea pigs, application of 10% suspension in dimethylphthalate was not irritating; a 25% suspension was mildly irritating, while a 40% suspension was moderately to strongly irritating. It did not produce allergic contact dermatitis.

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ In 96 day feeding trials no nutritional or clinical sign of toxicity was observed in albino rats receiving 5000-7500 mg/kg diet.

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ ... Repeated- dose dermal toxicity studies with IN Z1318-70 in male rabbits /were/ conducted in two phases: Study I and Study II. Five animals in each group (4 control in Study I) were sampled (blood collected) following a 21- day recovery period. At the end of the exposure period 5 rabbits/ group were killed for general gross pathological and male reproductive organ histological examination. The remaining animals were killed following the 21- day recovery period and similarly evaluated ... In Study I, one animal in the 5 mg/kg group exhibited mild conjunctival redness of the right eye, and one animal in the 15 mg/kg group exhibited corneal opacity of the left eye. In both studies (I and II) the incidence and severity of dermal erythema (slight to severe) and edema (slight to moderate) increased with exposure concentration of IN Z1318-70. Only slight erythema was observed in the control groups. Superficial necrosis and/ or necrosis were observed predominantly in animals treated with 1500 mg/kg and were located either on or near the actual application site. The dermal effects (erythema, edema, necrosis, epidermal scaling) for the most part can be attributed to the mechanical effect resulting from a combination of a moist microenvironment, the granularity of the test material, the daily wrapping and unwrapping, and daily attempts to remove excess test material. Although the test material may have produced a concentration- dependent dermal irritation and/ or altered the integrity of the skin, the dermal effects were not toxicologically significant The LOAEL is 1500 mg/kg/day, based on the increased severity and duration occurrence of dermal effects (erythema, edema, necrosis, epidermal scaling) (it is noted that the dose is greater than the limit dose). The NOAEL is 50 mg/kg/day.

For more Non-Human Toxicity Excerpts (Complete) data for SIDURON (16 total), please visit the HSDB record page.

Siduron is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(1). Siduron does not contain chromophores that absorb at wavelengths >290 nm(1) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC). In soil, siduron is not decomposed by sunlight(2). Substituted ureas may undergo hydrolysis under acidic as well as alkaline conditions(3).

After exposure in a thin film to full sunlight for 56 days, Siduron caused injury to germinating crabgrass identical with that caused by a nonirradiated check sample. Chemical analysis also verified that Siduron was not decomposed by sunlight.

The Agency has previously identified and required the submission of the generic (i.e., active ingredient-specific) data required to support reregistration of products containing siduron as an active ingredient. The Agency has completed its review of these generic data, and has determined that the data are sufficient to support reregistration of all products containing siduron. The Agency has completed its assessment of the human health and ecological risks associated with the use of pesticide products containing siduron. The Agency has determined that siduron products are eligible for reregistration provided the risk mitigation measures outlined in ... /the Reregistration Eligibility Decisiion/ document are adopted and label amendments are made to implement these mitigation measures ... Should a registrant fail to implement any of the reregistration requirements identified in ... /the Reregistration Eligibility Decisiion/ document, the Agency may take regulatory action to address these concerns.

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 continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer saftey standards, such as those described in 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 than those on List C, and with List C containing pesticides of greater concern than those on List D. Siduron is found on List C. Case No: 3130; Pesticide type: Herbicide; Case Status: OPP is reviewing data from the pesticide's producers regarding its human health and/or environmental effects, or OPP is determining the pesticide's eligibility for reregistration and developing the Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): Siduron (1-(2-methylcyclohexyl)-3-phenylurea); Data Call-in (DCI) Date(s): 09/30/92, 03/03/95, 10/13/95; AI Status: The producers of the pesticide have made commitments to conduct the studies and pay the fees required for reregistration, and are meeting those commitments in a timely manner.

Used as pre-emergence herbicide for control of annual grass weeds in desirable grass species and turf (including sod farms); [HSDB]

Farming (Pesticides) [Category: Industry]

For siduron (USEPA/OPP Pesticide Code: 035509) 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./

Registered for use on golf courses, sod farms, and residential turf.

Used for preemergence control of annual grasses such as barnyardgrass, crabgrass, foxtail, in newly-seeded or established bentgrass (certain strains), bluegrass, orchardgrass, perennial ryegrass, redtop, smooth brome, zoysia.

Selective herbicide, absorbed by the roots, with translocation in the xylem. Used as preemergence control of Digitaria species and annual grass weeds in newly-seeded grass (at 2-6 kg a.i./ha) or established turf (at 8-12 kg/ha).

Siduron is produced by reaction of phenyl isocyanate with 2-methylcyclohexylamine.

Preparation: Luckenbaugh, BE 631289 (1963 to du Pont)

Granular formulations and wettable powder formulations only.

Also various dilute formulations including mixt with fertilizers for dry applications.

... 70% powder for manufacturing use. Various granulars.

Tupersan Weed Killer, wettable powder, 50% siduron

For more Formulations/Preparations (Complete) data for SIDURON (23 total), please visit the HSDB record page.

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

It is recommended for treatment of grass at 2-8 kg AI/ha for new seedlings, 8-12 kg/ha for established turf.