시마진

Pesticides

Pesticide -> EPA IRIS

Herbicides

Active substance -> EU Pesticides database: Not approved

Pesticides -> Herbicides, Triazine

Herbicides

log Kow = 2.18

2.1

2.1

1.302 at 68 °F (NTP, 1992) - Denser than water; will sink

1.33 at 22 °C /as per source/

1.3 g/cm³

1.302

White solid

Colorless powder

Crystals from ethanol or methyl Cellosolve

less than 1 mg/mL at 72 °F (NTP, 1992)

400 PPM IN METHANOL @ 20 °C

3.0 ppm in n-pentane at 25 °C

Slightly sol in ethyl cellosolve, dioxane

In water, 6.2 mg/L (pH 7, 20 °C)

In ethanol 570, acetone 1500, toluene 130, n-octanol 390, n-hexane 3.1 (all in mg/L, 25 °C).

When heated to decomposition it emits very toxic fumes of /hydrogen chloride/ and nitrous oxides.

225-227 °C

437 to 441 °F (NTP, 1992)

225 to 227 °C (decomp)

437-441 °F

6.1e-09 mmHg at 68 °F (NTP, 1992)

0.00000002 [mmHg]

2.2X10-8 mm Hg at 25 °C

Vapor pressure, Pa at 20 °C: 8.1x10

6.1x10(-9)

Simazine is a white to off-white crystalline powder. (NTP, 1992)

Colorless to white crystals; [EXTOXNET]

WHITE CRYSTALLINE POWDER.

White to off-white crystalline powder.

VERY STABLE OVER SEVERAL YR OF SHELF LIFE, & ONLY SLIGHTLY SENSITIVE TO NATURAL LIGHT & EXTREME TEMPERATURES WHICH WOULD OCCUR NORMALLY.

Aquazine, Princep 4G, Princep 4L, Princep 80W, Princep Caliber 90 /have a/ half life of at least 3 to 5 yr when stored in a dry place.

Warning

H351: Suspected of causing cancer [Warning Carcinogenicity]

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

Warning

H302 (51.7%): Harmful if swallowed [Warning Acute toxicity, oral]

P203, P264, P264+P265, P270, P273, P280, P301+P317, P305+P351+P338, P318, P330, P337+P317, P391, P405, and P501 (click each P-code to see the statement)

Hazard Traits - Developmental Toxicity; Other Toxicological Hazard Traits; Reproductive Toxicity

Regulation (EC) No 1107/2009 (amended)

04/247/EC

Status: Active Update: 15-02-2018 https://echa.europa.eu/registration-dossier/-/registered-dossier/22368

Simazine: HSNO Approval: HSR003354 Approved with controls

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

Literature sources indicate that this chemical is nonflammable. (NTP, 1992)

Combustible. Gives off irritating or toxic fumes (or gases) in a fire. Finely dispersed particles form explosive mixtures in air.

Simazine is slightly to practically nontoxic. Damage to the liver and other organs is observed in high-dose feeding studies of experimental animals. [EXTOXNET] The following herbicides have an oral LD50 of >1 gm/kg and have little or no acute toxicity in humans: Alachlor, Amitrole, Ammonium sulfamate, Atrazine, Dalapon, Dicamba, Glyphosphate, Monuron, Oryzalin, Picloram, Propanil, Simazine, etc. [LaDou, p. 613] For the triazine herbicides, systemic toxicity unlikely unless large amounts are ingested; May cause irritation; [EPA Pesticides, p. 121] Not acutely toxic; TLV Basis: hematologic effects; In female rats, depression in red blood cell count, hemoglobin and hematocrit and elevations in mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) and white blood cell count were seen at both the mid and high doses and the NOEL for these effects was 10 ppm or 0.52 mg/kg/day. Dermatitis has been reported, but a repeated patch insult test with 50 human subjects showed the 80% wettable powder formulation of simazine was not a primary irritant, defatting agent, or sensitizer. [ACGIH]

The major hazards encountered in the use and handling of simazine stem from its toxicologic properties. Toxic by all routes (ie, inhalation, ingestion, dermal contact), exposure to this colorless to white powder may occur from its manufacture, formulation, and use as an herbicide. Effects from exposure may include eye and dermal irritation, shortness of breath, muscle spasms, ataxia, and anorexia. In activities and situations where over exposure may occur, wear a self-contained breathing apparatus and personal protective clothing. If contact should occur, immediately flush affected skin or eyes with running water for at least 15 minutes. Remove contaminated clothing and shoes at the site. While simazine does not ignite easily, it may burn with the production of irritating and poisonous gases. For fires involving simazine, extinguish with dry chemical, CO2, Halon, water spray, fog, or standard foam. Simazine may be shipped domestically via air, rail, road, and water, in containers bearing the label "Poison". Simazine should be stored in its original container, in dark, well-ventilated areas, away from heat, sparks, and other sources of ignition. Small dry spills of simazine may be placed into a clean, dry, covered container for later disposal (liquid solutions are first absorbed in sand or other noncombustible absorbent). Large liquid spills should be diked far ahead to prevent simazine from entering water sources and sewers. Before implementing land disposal of simazine, consult with regulatory agencies for guidance.

USEPA/Office of Pesticide Programs; Reregistration Eligibility Decision Document - Simazine. 267 p. EPA 738-R-06-008 (April 2006) This document presents EPA's revised human health and environmental fate and effects risk assessments, its progress toward tolerance reassessment, and the reregistration eligibility decision for simazine. The document consists of six sections. Section I contains the regulatory framework for reregistration and tolerance reassessment. Section II provides a description of the chemical and a profile of the use and usage of the chemical. Section III provides a summary of the human health and ecological risk assessments which have been revised based on data, public comments, and other information received in response to the preliminary risk assessments. Section IV presents the Agency's risk management, reregistration eligibility, and tolerance reassessment decisions. Section V summarizes the data requirements necessary to confirm the reregistration eligibility decision as well as label changes and language necessary to implement the risk mitigation measures outlined in Section IV. Section VI, the Appendices, provides related information and supporting documents. The preliminary and revised risk assessments for simazine are available in the public docket EPA-HQ-OPP-2005-0151 located on-line in FDMS, http://www.regulations.gov.

US EPA/Office of Pesticides Programs, Health Effects Division; Cumulative Risk from Triazine Pesticides. 65 p. (March 2006). As part of the tolerance reassessment process under the Food Quality Protection Act (FQPA) of 1996, EPA must consider available information concerning the cumulative effects on human health resulting from exposure to multiple chemicals that have a common mechanism of toxicity. Based on use patterns and the likelihood of exposure to atrazine, simazine, and propazine, only atrazine and simazine and their common metabolites (DEA, DIA and DACT) have been included in the the triazine cumulative risk assessment.

European Chemicals Bureau; IUCLID Dataset, Simazine (CAS No. 122-34-9) (2000 CD-ROM edition). Available from the Database Query page at: http://ecb.jrc.it/esis/esis.php as of June 6, 2007. Information on usage patterns, toxicity, and ecotoxicity reported to the European Union by industry is described.

Venkat JA etal; Environ Mol Mutagen 25 (1): 67-76 1995. Relative genotoxic activities of pesticides evaluated by a modified SOS microplate assay.

Mersch-Sundermann V et al; Mutagenesis 9 (3): 205-24 May 1994. SOS induction in Escherichia coli and Salmonella mutagenicity: a comparison using 330 compounds.

Tolerances are established for residues of the herbicide simazine (2-chloro-4,6-bis(ethylamino)-s-triazine) in or on the following raw agricultural commodities: [Table#3555]

Tolerances are established for the combined residues of the herbicide simazine (2-chloro-4,6-bis(ethylamino)-s-triazine) and its metabolites 2-amino-4-chloro-6-ethylamino-s-triazine and 2,4-diamino-6-chloro-s-triazine in or on raw agricultural commodities as follows: [Table#3556]

The Agency has completed its assessment of the dietary (both food and drinking water), residential, occupational, and ecological risks associated with the use of pesticide products containing the active ingredient simazine. Based on a review of these data and on public comments on the Agency's assessments for the active ingredient simazine, the Agency has sufficient information on the human health and ecological effects of simazine to make decisions as part of the tolerance reassessment process under FFDCA and reregistration process under FIFRA, as amended by FQPA. The Agency has determined that products containing simazine are eligible for reregistration provided that the risk mitigation measures outlined in this document are adopted and label amendments are made to reflect these measures.

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. Simazine is found on List A, which contains most food use pesticides and consists of the 194 chemical cases (or 350 individual active ingredients) for which EPA issued registration standards prior to FIFRA, as amended in 1988. Case No: 0070; Pesticide type: herbicide; Registration Standard Date: 03/01/84; 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): Simazine; Data Call-in (DCI) Date(s): 09/11/91, 03/03/95, 10/13/95; AI Status: The producers of the pesticide has made commitments to conduct the studies and pay the fees required for reregistration, and are meeting those commitments in a timely manner.

Fires involving this material can be controlled with a dry chemical, carbon dioxide or Halon extinguisher. (NTP, 1992)

Use water spray, foam, powder, carbon dioxide.

Fresh air, rest.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Give one or two glasses of water to drink. Rest. Refer for medical attention .

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

This chemical is a combustible liquid. Use dry chemical, carbon dioxide, water spray, or alcohol foam extinguishers. Poisonous gases are produced in fire. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Notify local health and fire officials and pollution control agencies. From a secure, explosion-proof location, use water spray to cool exposed containers. If cooling streams are ineffective (venting sound increases in volume and pitch, tank discolors, or shows any signs of deforming), withdraw immediately to a secure position. If employees are expected to fight fires, they must be trained and equipped in OSHA 1910.156.

Extinguish fire using agent suitable for type of surrounding fire. ... Use water in flooding quantities as fog. Use "alcohol foam", dry chemical or carbon dioxide. Wear positive pressure self contained breathing apparatus when fighting fires involving this material. /Triazine pesticide, solid, not otherwise specified (compounds and preparations), (agricultural insecticides, not elsewhere classified, other than liquid)/

Avoid breathing dusts & fumes from burning material. Keep upwind. /Triazine pesticide, solid, not otherwise specified (compounds and preparations), (agricultural insecticides, not elsewhere classified, other than liquid)/

Product must be stored in its sealed original containers, in well aired, fresh & dry storehouses or in shaded & possibly well aired places. It is recommended that the product be kept away from sources of heat, free flames or spark generating equipment.

Storage stability is three years at room temperature under dry conditions.

Evacuate persons not wearing protective equipment from area of spill or leak until clean-up is complete. Remove all ignition sources. Collect powdered material in the most convenient and safe manner and deposit in sealed containers. Ventilate area after clean-up is complete. It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Contact your Department of Environmental Protection or your regional office of the federal EPA for specific recommendations. If employees are required to clean-up spills, they must be properly trained and equipped. OSHA 1910.120(q) may be applicable.

SMALL SPILLS AND LEAKAGE: Should a spill occur while you are handling this chemical, FIRST REMOVE ALL SOURCES OF IGNITION, then you should dampen the solid spill material with 60-70% ethanol and transfer the dampened material to a suitable container. Use absorbent paper dampened with 60-70% ethanol to pick up any remaining material. Seal the absorbent paper, and any of your clothes, which may be contaminated, in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with 60-70% ethanol followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

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.

This pesticide is toxic to aquatic invertebrate. 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 Policies Discharge Elimination System (NPDES) permit and the permitting authority has been notified in writing prior to discharge.

This pesticide is toxic to aquatic invertebrates. Except when following the Directions for Use for applications to aquariums and outdoor ponds when permitted on the label, do not apply directly to water, to areas where surface water is present, or to intertidal areas below the mean high water mark. Runoff and drift from treated areas may be hazardous to aquatic organisms in neighboring areas. Do not contaminate water when disposing of equipment wash water. For aquatic use in aquariums or ornamental ponds: Do not apply to or allow discharge to lakes, flowing water, or ponds with outflow. Do not contaminate domestic livestock or irrigation water supplies."

Strong acid or alkaline hydrolysis leads to complete degradation of simazine. However, large quantities of simazine should be incinerated in a unit operating at 850 °C equipped with off-gas scrubbing equipment. In accordance with 40CFR 165 recommendations for the disposal of pesticides and pesticide containers. Must be disposed of properly by the following package label directions or by contacting your state pesticide or environmental control agency or by contacting your regional EPA office.

For more Disposal Methods (Complete) data for SIMAZINE (11 total), please visit the HSDB record page.

Personal protection: chemical protection suit including self-contained breathing apparatus. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.

Follow manufacturer's instructions for cleaning/maintaining PPE. If no such instructions for washables exist, use detergent and hot water. Keep and wash separately from other laundry. Discard clothing and other absorbent materials that have been drenched or heavily contaminated with this product's concentrate. Do not reuse them.

Users should wash hands before eating, drinking, chewing gum, using tobacco, or using the toilet. Users should remove clothing/PPE immediately if pesticide gets inside. Then wash thoroughly and put on clean clothing. Users should remove PPE immediately after handling this product. Wash the outside of gloves before removing. As soon as possible, wash thoroughly and change into clean clothing.

For Christmas trees, do not enter or allow worker entry into treated areas during restricted-entry interval (REI) of 48 hours. For all other crops and use-patterns, do not enter or allow worker entry into treated areas during the REI of 12 hours.

Product must not be mixed or loaded within 50 feet of intermittent streams and rivers, natural or impounded lakes and reservoirs. Product must not be applied within 66 feet of points where field surface water runoff enters perennial or intermittent streams and rivers or within 200 feet of natural or impounded lakes and reservoirs. If this product is applied to highly erodible land, the 66 foot buffer or setback from runoff entry points must be planted to crop, or seeded with grass or other suitable crop. Product must not be mixed or loaded, or used within 50 feet of all wells, including abandoned wells, drainage wells, and sink holes. Operations that involve mixing, loading, rinsing, or washing of this product into or from pesticide handling or application equipment or containers within 50 feet of any well are prohibited, unless conducted on an impervious pad constructed to withstand the weight of the heaviest load that may be positioned on or moved across the pad. ...

For more Preventive Measures (Complete) data for SIMAZINE (12 total), please visit the HSDB record page.

Recent studies have demonstrated the potentiating effects of triazine herbicides, such as atrazine and its analogs, to the toxicity of a variety of organophosphate (OP) insecticides. One such OP insecticide, chlorpyrifos, has been the topic of much concern because of its prevalence in the environment. This study focused on examining the effects of 10 select triazine herbicides at concentrations of 1 mumole/L (approximately 200 mug/L) to chlorpyrifos with Hyalella azteca. The compounds selected include atrazine, three of its degradation products, and six other herbicide active ingredients. Toxicity tests were performed using a two-way analysis of variance matrix design with effect levels determined by way of probit analysis. Atrazine was found to have the greatest acutely lethal effect to H. azteca, followed by its closest degradation product, deethylatrazine. Two of the six atrazine analogs, simazine and cyanazine, also showed significant effects to the insecticide's toxicity. Synergistic ratios (SRs) were calculated to compare the effect magnitudes for each of the herbicides. The highest ratio obtained was with atrazine (SR = 1.42). A majority of the past studies involving mixtures of triazines and OPs have examined the potentiation effects of active-use triazine herbicides on Chironomus species. However, compared with the acute effects previously obtained for Chironomus species, H. azteca show a higher tolerance to the presence of the triazine herbicides, even at levels often considered as being at the high end of environmentally relevant concentrations. ..

A series of recent studies demonstrated that the triazine herbicide atrazine, although not itself acutely toxic, potentiated the toxicity of certain organophosphate insecticides (OPs) to the midge Chironomus tentans. In the current study, a series of triazine herbicides and triazine herbicide degradation products were tested to determine if other triazines potentiate OP toxicity to midges. Chlorpyrifos and diazinon were the OPs tested. ... All of the triazine herbicides tested (atrazine, simazine, cyanazine, and hexazinone) were capable of potentiating the toxicity of the OPs, whereas the degradation products (s-triazine, deethylatrazine, and deisopropylatrazine) had less effect. In most cases, a triazine concentration of 100 ug/L was necessary to significantly increase OP toxicity, and higher concentrations of triazine caused a greater degree of potentiation. Changes in EC50 values ranged from no change to a 2.5-fold increase in toxicity. Generally, EC50 values changed by less than a factor of 2, indicating that the effect may be of limited concern in regard to future risk assessments of OPs.

Goldfish (Carassius auratus) were exposed to a mixture of herbicides, namely atrazine, simazine, diuron, and isoproturon (ASDI) at a cumulative concentration of 50 ug/L for 12 weeks. Control fish and exposed fish were sampled at 4, 8 and 12 weeks of exposure to observe the combined impact of herbicides on non-specific and specific mechanisms of immunity and antioxidant defenses. The antioxidant defenses were evaluated in hemopoietic organs and liver. ASDI-induced stress was reflected as a significant induction of superoxide (O(2)(-)) production in phagocytic cells of head kidney and spleen. In addition, plasma lysozyme activity was consistently high in the treatment group. Specific immunity was assessed by antibody titer responses following immunization of the fish with sheep red blood cells (SRBCs). Antibody titer was reduced throughout the period of observation in ASDI-treated fish. This reduction was found to be significant at week 4 (p<0.05). Herbicide-exposed fish showed reduced resistance against pathogen invasion but remarkable enhancement in lysozyme activity. The ASDI-induced oxidative stress in spleen, kidney and liver was reflected as a change in the antioxidant enzyme activities in these vital organs of fish. /The authors concluded that the/ data indicate that herbicides at concentrations present in water bodies in Europe cause immune suppression in goldfish.

LC50 /Colinus virginianus/ (Bobwhite, age 10 days) oral >5000 ppm in 5 day diet /sample purity 99.1%/

LC50 /Coturnix japonica/ (Japanese quail, age 12 days) oral >3720 ppm in 5 day diet /sample purity 99.1%/

LC50 /Phasianus colchicus/ (Pheasant, age 10 days) oral >5000 ppm in 5 day diet /sample purity 99.1%/

LC50 /Anas platyrhynchos/ (Mallard duck, age 10 days old) oral >5000 ppm in 5 day diet

For more Ecotoxicity Values (Complete) data for SIMAZINE (36 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values ranging from 78 to 3,559(2,3), indicate that simazine is expected to have high to slight mobility in soil(SRC). Increasing sorption has been observed with decreasing pH(4). Volatilization of simazine from moist soil surfaces is not expected to be important(SRC) given an estimated Henry's Law constant of 9.4X10-10 atm-cu m/mole(SRC), derived from its vapor pressure, 2.2X10-8 mm Hg(5) and water solubility of 6.2 mg/L(5). Simazine is not expected to volatilize from dry soil surfaces based on its vapor pressure(5). The half-lives for degradation (purportedly mainly soil-catalyzed hydrolysis) of simazine in Hatzenbuhl soil at pH 4.8 and Neuhofen soil at pH 6.5 are 45 and 100 days, respectively(6). Estimated soil hydrolysis half-lives in Wongan Hills loamy sand at 9, 20, and 28 °C were 144, 37, and 21 days, respectively(7). Humic and fulvic acids have been observed to favor the hydrolysis of triazine molecules(8). Microbial breakdown in soil results in degradation of simazine at very variable rates, half-lives range from 27 to 102 days (median 49 days); temperature and moisture are the main factors affecting the rates(5). Complete mineralization of the s-triazine ring to CO2 by microbial degradation of triazine herbicides is typically low, 0.5 to 5%, in soil(2). During 6 months incubation in coarse sandy soils at 15 °C, approx. 4 to 7% of the applied (14)C-ring-labeled-simazine was evolved as (14)CO2(9). Half-lives of simazine in soil biometer studies ranged from 32 to 91 days(10). N-Desethyl simazine and 2-chloro-4,6-bisamino-s-triazine were identified as metabolites(10).

TERRESTRIAL FATE: It has been reported that simazine and other s-triazines can be utilized by certain soil microorganisms as a source of energy(1). Microbial degradation products of simazine in soil include 2-chloro-4-amino-6-ethylamino-1,3,5-triazine and 2,4-dihydroxy-6-amino-1,3,5-triazine(1). Mineralization of 10.4% of (14)C-labeled simazine in 110 days has been reported in a clay-lime soil; no degradation of simazine was detected in a soil suspension test without the addition of glucose as an energy source suggesting that degradation of simazine in these soil experiments was due to co-metabolism(2). Reported persistence of simazine in soil varies from a half-life of <1 month(3) to no degradation being observed in 3.5 months(4). The amount of organic matter in the soil may have a significant effect on the persistence of simazine(3). Additions of 1%, 5%, and 10% leaf compost to soil gave simazine half-lives of about 140, 60, and 40 days, respectively(3).

AQUATIC FATE: Based on a classification scheme(1), Koc values ranging from 78 to 3,559(2,3), indicate that some adsorption of simazine to suspended solids and sediment in the water column is expected(SRC). Increasing sorption has been observed with decreasing pH(14). Simazine is not expected to volatilize from water surfaces(4) based on an estimated Henry's Law constant of 9.4X10-10 atm-cu m/mole(SRC), derived from its vapor pressure, 2.2X10-8 mm Hg(5) and water solubility of 6.2 mg/L(5). According to a classification scheme(6), BCFs ranging from <1 to 55(7-9) suggest bioconcentration in aquatic organisms is low to moderate(SRC). Simazine is stable at pH 7 and 9 but the hydrolysis half-life at pH 5 and 25 °C is 70 days(10). The product of simazine hydrolysis is 2-hydroxy-4,6-bis(ethylamino)-1,3,5-triazine(10). Humic and fulvic acids have been observed to favor the hydrolysis of triazine molecules(11). Biodegradation in surface water samples from three ponds in Nagoya City, Japan, ranged from 0 to 30% after four days incubation; after 7 days incubation, biodegradation ranged from 0 to 24%(12). In Po River water, an initial simazine concentration of 5 ug/L was reduced to 3.1 and 2.5 ug/L after 24 and 384 hours incubation, respectively(13). A pKa of 1.62(5) indicates simazine will exist predominantly in the unionized form under environmental pHs(SRC).

AQUATIC FATE: Dissipation of simazine in pond and lake water was variable, with half-lives ranging from 50 to 700 days. The degradation compound G-28279 /1,3,5-triazine-2,4-diamine, 6-chloro-N-ethyl-; CAS Number 1007-28-9/ was identified in lake water samples.

For more Environmental Fate (Complete) data for SIMAZINE (6 total), please visit the HSDB record page.

Simazine was not detected (detection limit 10 ppb) in 25 composite samples of Ontario-grown potatoes analyzed in 1983-1985(1). Simazine was detected in 1 out of 862 samples of domestic oranges in 1985 to 1991 at a concn of 0.10 ppm(2). Simazine was identified, not quantified, in an unspecified number of food items in the 2002 and 2003 FDA Market Basket Survey(3). Simazine was identified, not quantified, in 40% of wheat samples collected from different locations in Saudi Arabia(4). Simazine was detected in 3 out of 13,980 food samples analyzed by six states (CA, FL, MA, NY, VA, and WI) for fiscal year 1988(5).

In a goat dosed for 10 days with [14C]simazine at a dose equivalent of 5 ppm [12x the maximum theoretical dietary burden (MTDB)], total radioactive residue (TRR) in milk plateaued by Day 5 at 0.10 ppm. ...In another study, a goat was dosed for 7 days with [14C]simazine at a dose equivalent to 50 ppm in the diet (119x). TRR in milk ranged from 0.71-1.07 ppm during the 7-day dosing period.

/BIRDS and MAMMALS/ Mallard ducks were exposed to dietary levels of simazine of 2.0 and 20.0 ppm from prior to the onset of egg laying through the normal egg production cycle. Reproductive parameters analyzed were: eggs laid, eggshell cracks, viable embryos, live 3-wk embryos, normal hatchlings, 14 day old survivors, and eggshell thinning. No reproductive impairment was found.

/AQUATIC SPECIES/ The presence of atrazine in agricultural sites has been linked to the decline in amphibian populations. The efforts of the scientific community generally are directed toward investigating the long-term effect of atrazine on complex functions (reproduction or respiration), but in the present study, we investigated the short-term effect on the short-circuit current (ISC), a quantitative measure of the ion transport operated by frog (Rana esculenta) skin. Treatment with 5 uM atrazine (1.08 mg/L) does not affect the transepithelial outfluxes of [14C]mannitol or [14C]urea; therefore, atrazine does not damage the barrier properties of frog skin. Atrazine causes a dose-dependent increase in the short-circuit current, with a minimum of 4.64 + or -0.76 uA/sq cm (11.05% + or -1.22%) and a maximum of 12.7 + or -0.7 uA/sq cm (35% + or -2.4%) measured at 10 nM and 5 uM, respectively. An increase in ISC also is caused by 5 uM ametryne, prometryn, simazine, terbuthylazine, or terbutryn (other atrazine derivatives). In particular, atrazine increases the transepithelial 22Na+ influx without affecting the outflux. Finally, stimulation of ISC by atrazine is suppressed by SQ 22536, H89, U73122, 2-aminoethoxydiphenyl borate, and W7 (blockers of adenylate cyclase, protein kinase A, phospholipase C, intracellular Ca2+ increase, and calmodulin, respectively), whereas indomethacin and calphostin C (inhibitors of cyclooxygenase and protein kinase C, respectively) have no effect.

/AQUATIC SPECIES/ Three species of freshwater fish, Tilapia mossambica, Punctius ticto and Heteropneustes fossilis, were exposed to simazine at 1, 5 or 10 ppm. At 10 ppm, it caused death in P ticto in about 10 days and in about 19 days in H fossilis. Proposed safe concentration limits are 0.1 ppm for T mossambica and P ticto and 1 ppm for H fossilis.

/AQUATIC SPECIES/ The median lethal concentration for simazine, expressed as 80% WP formulation, to fingerling striped bass (Morone saxatilis) was >180 mg/L in hard and soft water.

For more Ecotoxicity Excerpts (Complete) data for SIMAZINE (26 total), please visit the HSDB record page.

Simazine was detected in 6 of 48 wells suspected of contamination due to spills between 1979 and 1984 in rural Ontario, Canada(1). Simazine was detected, not quantified, in 1 (oil refinery final effluent) of 10 final effluents from industrial plants and publicly-owned treatment works in the US in 1980(2). Whereas simazine was not detected in a sample of industrial effluent nor in the water of the river into which the effluent was discharged, it was detected at 1,000 and 10 ppm in the sediment of the river 1.5 km downstream from the plant and near a nearby dam, respectively(3).

Tolerances are established for residues of the herbicide simazine (2-chloro-4,6-bis(ethylamino)-s-triazine) in or on the following raw agricultural commodities: [Table#3555]

Tolerances are established for the combined residues of the herbicide simazine (2-chloro-4,6-bis(ethylamino)-s-triazine) and its metabolites 2-amino-4-chloro-6-ethylamino-s-triazine and 2,4-diamino-6-chloro-s-triazine in or on raw agricultural commodities as follows: [Table#3556]

The Agency has completed its assessment of the dietary (both food and drinking water), residential, occupational, and ecological risks associated with the use of pesticide products containing the active ingredient simazine. Based on a review of these data and on public comments on the Agency's assessments for the active ingredient simazine, the Agency has sufficient information on the human health and ecological effects of simazine to make decisions as part of the tolerance reassessment process under FFDCA and reregistration process under FIFRA, as amended by FQPA. The Agency has determined that products containing simazine are eligible for reregistration provided that the risk mitigation measures outlined in this document are adopted and label amendments are made to reflect these measures.

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. Simazine is found on List A, which contains most food use pesticides and consists of the 194 chemical cases (or 350 individual active ingredients) for which EPA issued registration standards prior to FIFRA, as amended in 1988. Case No: 0070; Pesticide type: herbicide; Registration Standard Date: 03/01/84; 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): Simazine; Data Call-in (DCI) Date(s): 09/11/91, 03/03/95, 10/13/95; AI Status: The producers of the pesticide has made commitments to conduct the studies and pay the fees required for reregistration, and are meeting those commitments in a timely manner.

(AZ) ARIZONA 35 ug/l

(ME) MAINE 3.5 ug/l

(MN) MINNESOTA 4 ug/L

The underlying mechanism of the neuroendocrine and neuroendocrine-related changes associated with atrazine and similar triazines involves the disruption of the hypothalamic-pituitary-gonadal (HPG) axis .... Specifically, several triazines can alter hypothalamic gonadotrophin-releasing hormone (GnRH) and catecholamine (dopamine and norepinephrine) levels. In both humans and rats, hypothalamic GnRH controls pituitary hormone secretion, i.e., LH and PRL. The result of changes in GnRH and catecholamines in turn leads to alterations in pituitary LH and PRL secretion. The hypothalamic-pituitary axis is involved in the development of the reproductive system, and its maintenance and functioning in adulthood. Additionally, reproductive hormones modulate the function of numerous other metabolic processes (i.e., bone formation, and immune, central nervous system (CNS) and cardiovascular systems.

After subchronic and chronic exposure to simazine, a variety of species were shown to exhibit neuroendocrine effects resulting in both reproductive and developmental consequences that are considered relevant to humans. These effects are biomarkers of a neuroendocrine mechanism of toxicity that is shared by several other structurally-related chlorinated triazines including atrazine, propazine, and three chlorinated degradates -des-isopropyl atrazine or DIA, and des-ethyl atrazine or DEA, and iaminochlorotriazine or DACT - the first and last of which can result from the degradation of simazine. These six compounds disrupt the hypothalamic-pituitary-gonadal (HPG) axis, part of the central nervous system, causing cascading changes to hormone levels and developmental delays. These neuroendocrine effects are considered the primary toxicological effects of regulatory concern for all subchronic and chronic exposure scenarios including dietary risk from food and drinking water, residential risk, and occupational risk. Simazine's two chlorinated degradates, DIA and DACT, are considered to have toxicity equal to the parent compound in respect to their common neuroendocrine mechanism of toxicity. Another degradate, hydroxy-simazine, was identified, which is expected to have a different toxicological profile from simazine based on the toxicological data available for an analogous metabolite for atrazine, hydroxy-atrazine.

Simazine has been grouped with several structurally-related, chlorinated triazines (e.g., atrazine, propazine, and 3 chlorotriazine degradates common to atrazine, simazine and propazine) on the basis of a common mechanism of toxicity for disruption of the hypothalamic-pituitary-gonadal (HPG) axis. As a result of their common mechanism of toxicity, exposure to simazine, like exposure to atrazine, results in reproductive and developmental effects and consequences that are considered relevant to humans. ...This mechanism involves a central nervous system (CNS) toxicity, specifically, neurotransmitter and neuropeptide alterations at the level of the hypothalamus, which cause cascading changes to hormone levels, e.g., suppression of the luteinizing hormone surge prior to ovulation resulting in prolonged estrus in adult female rats (demonstrated with atrazine and simazine), and developmental delays, i.e., delayed vaginal opening and preputial separation in developing rats (studied in atrazine but not simazine). ...This CNS mechanism of toxicity also results in mammary tumors specific to female Sprague- Dawley rats exposed to simazine and atrazine; however, the particular cascade of events leading to tumor formation in this specific strain of rat is not considered to be operative in humans. Consequently, atrazine has been classified as "Not Likely to be Carcinogenic to Humans."

Various investigations indicate that the ability of triazines to interfere with photosynthesis is responsible for their biological activity. Simazine depletes carbohydrate by inhibiting the formation of sugars. The triazines inhibit the Hill reaction, ie, the formation of oxygen by chloroplasts of certain plants in the presence of light & ferric salts.

For more Mechanism of Action (Complete) data for SIMAZINE (7 total), please visit the HSDB record page.

Simazine is metabolized and excreted in the rat within 72 hours of dosing. Most of the excreted simazine residues were detected in the urine (49%) and feces (41%) with minor amounts respired as CO2. Simazine is metabolized in the rat through the removal of alkyl side chains and conjugation of the triazine ring with glutathione-S-transferase. The mono- and di-dealkylated compounds, 2-chloro-4-ethylamino- 6-amino-s-triazine and diaminochlorotriazine (DACT), respectively, are the major rat degradates. Conjugated mercapturates of hydroxy simazine were also detected.

The metabolic pathway in plants is similar to that in rats. Plant metabolism occurs via several competing routes. In one major route the N-ethyl groups are cleaved leaving the bare amine attached to the ring. First one ethyl group is lost, then both are lost, ultimately leaving diaminochlorotriazine (DACT). DACT can subsequently proceed to replacement of the chlorine with a proline group, which is attached to the triazine via the proline nitrogen. In a second major route of metabolism, the chloro group on simazine is replaced by a hydroxy group to hydroxysimazine, which can proceed by loss of the ethyl groups to diaminohydroxytriazine, the hydroxy equivalent of DACT. The diaminohydroxytriazine can then under go replacement of one or both amines by hydroxy groups ultimately leading to cyanuric acid. Alternatively, the chlorine in simazine can be replaced by glutathione and through a variety of intermediate conjugates can be eventually lysed to NH2-simazine, and then presumably loss of one or both ethyl groups.

The metabolic pathway in livestock is also similar to that in plants and rats with one exception; animals do not metabolize simazine directly to hydroxy-simazine, but animals may receive hydroxy simazine through feeds. Several studies have been performed on the metabolism of simazine in livestock and poultry. In animals, in general, simazine residues tend to lose one or both ethyl groups to form the chloro-metabolites or to replace the chloro- group with a hydroxygroup and then to lose one of both ethyl groups. Feeding with hydroxy-simazine leads to formation, through loss of one or both ethyl groups of hydroxy-metabolites only. A glutathione conjugate is also formed from the hydroxy-simazine.

Ruminants. In a goat dosed for 10 days with [14C]simazine at a dose equivalent of 5 ppm [12x the maximum theoretical dietary burden (MTDB)], total radioactive residue (TRR) in milk plateaued by Day 5 at 0.10 ppm. TRR in tissue samples collected 48 hours after the final dose ranged from 0.02 ppm in fat to 0.93 ppm in liver. After residues plateaued in milk (at 2% of the administered dose), the major metabolite in milk (23.5% TRR) was identified as diaminochlorotriazine, along with minor amounts (0.25% TRR) of simazine and of desethylsimazine (1.3% TRR). Metabolites in the aqueous fraction and the hydrolysate of the casein fraction were characterized as amino acid and peptide conjugates of simazine. In another study, a goat was dosed for 7 days with [14C]simazine at a dose equivalent to 50 ppm in the diet (119x). TRR in milk ranged from 0.71-1.07 ppm during the 7-day dosing period. TRR in tissues collected within 24 hours of the final dose were 0.06-0.10 ppm in fat, 0.69-0.71 ppm in muscle, 3.03 ppm in kidneys, 2.59 ppm in brain, 0.78 ppm in heart, and 3.24 ppm in liver. Components of the TRR identified in milk and tissues are listed in the table below. Simazine accounted for 3.8-10.8% of the TRR in tissues, but was not detected in milk. DACT was the major metabolite in milk (30.3% TRR) and accounted for 4.2-5.2% TRR in liver and kidney, and 13.8% TRR in muscle. Desethylsimazine was detected in liver and kidney at 10.7-16.9% TRR, but was not detected in muscle and milk. A glutathione conjugate of desethylsimazine was also tentatively identified in kidney (18.7% TRR) and milk (14.9% TRR). Desethylhydroxy-simazine constituted up to 32.9% of the TRR in liver, but may have been an artifact of proteolysis.

For more Metabolism/Metabolites (Complete) data for SIMAZINE (13 total), please visit the HSDB record page.

Simazine has known human metabolites that include N-Desethylsimazine.

At the low dose (0.5 mg/kg) of radiolabeled simazine, the principal route of excretion was via the urine, however, at the higher dose (200 mg/kg) the principal route of excretion was via the feces. Significant radioactive residues remained in the tissues of the rat for extended periods of time. Results indicate that 94 to 99% of the elimination of radioactive material occurred within 48 to 72 hours with a half-life of 9 to 15 hours. Elimination of the remaining radioactivity exhibited 21- to 32-hour half-life values. Heart, lung, spleen, kidney, and liver appear to be principal sites of retention of radioactivity. However, erythrocytes concentrated radioactivity to higher levels than did other tissues, perhaps due to high affinity of the triazine ring for cysteine residues of hemoglobin, a phenomenon apparently unique to rodent species.

In a dermal absorption study, male Charles River Sprague-Dawley rats received either 0.1, 0.5 mg/sq cm of 14C-simazine ( two vials used: radiochemical purity: 98% for the low dose and 96%, for the high dose, specific activity: 28.0 uCi/mg and 2.4 uCi/mg). Four animals per dose were treated and then the treated area of skin and the surrounding area were covered with a protective device. Animals were then placed in metabolism cages for the duration of the exposure period. Either 2, 4, 10 or 24 hrs following exposure animals were sacrificed. Following sacrifice the exposure sites were washed with liquid Dove and water and both the treated area of skin and skin surrounding the treated area (the skin covered by the protective device) were collected. The soap and water rinses, the skin samples, urine, feces, blood, carcass, cage wash, and other relevant samples were all analyzed for radioactivity. Dermal absorption was less than 1% at both doses and all time points. However, 11-20% of the low dose and 31-41% of the high dose remained on the skin and is thus potentially absorbable.

/Simazine is/ absorbed mostly through plant roots with little or no foliar penetration. It has low adhering ability and is readily washed from foliage by rain. Following root absorption it is translocated acropetally in the xylem, accumulating in apical meristems and leaves of plants.

Simazine was readily absorbed and distributed in spruce seedlings. Degradation of simazine took place in roots and stem to the hydroxy analog... metabolites, but no simazine, were observed in needles.

For more Absorption, Distribution and Excretion (Complete) data for SIMAZINE (8 total), please visit the HSDB record page.

Used as a broadleaf herbicide; [EXTOXNET] Inhibits photosynthesis in weeds after application to soil; Used in crops (apples, oranges, almonds, corn), lawns, and in ponds and aquariums (algicide); [ACGIH]

Farming (Pesticides) [Category: Industry]

For simazine (USEPA/OPP Pesticide Code: 80807) 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./

Simazine is a selective herbicide used for control of broadleaf weeds and annual grasses in corn, established alfalfa, fruit, nuts, asparagus, ornamentals, and turf.

Selective systemic herbicide. Control of most germinating annual grasses and broad-leaved weeds.

Simazine is also used for selective control of algae and submerged weeds in ponds. It is approved for algae control in swimming pools, large aquaria, ornamental fish ponds, fountains, and recirculating water cooling towers.

(1975) 3.54X10+9 G (CONSUMPTION)

(1976) PROBABLY GREATER THAN 2.27X10+6 G

Production volumes for non-confidential chemicals reported under the Inventory Update Rule. [Table#3557]

This chemical is listed as a High Production Volume (HPV) (65FR81686). Chemicals listed as HPV were produced in or imported into the U.S. in >1 million pounds in 1990 and/or 1994. The HPV list is based on the 1990 Inventory Update Rule. (IUR) (40 CFR part 710 subpart B; 51FR21438).

HERBICIDE, OF WHICH APPROXIMATELY 49% IS USED ON CORN, 8% ON CITRUS, 6% ON DECIDUOUS FRUITS, 5% ON FIELD CROPS, 3% ON VEGETABLES, 17% FOR INDUSTRIAL/COMMERCIAL USES, & 13% FOR AQUATIC USES (1975)

Estimated noncropland use of simazine: 1.925 to 3.300 million lbs AI/yr. National use of simazine by crop in 1987/89, lbs AI/yr: alfalfa, 420,348; almonds, 85,537; apples, 140,515; artichokes, 5,878; asparagus, 93,709; avocados, 43,355; blueberries, 30,767; cherries, 20,538; corn, 1,552,755; cranberries, 1,488; filberts, 3,447; grapes, 290,296; nectarines, 4,374; olives, 6,653; peaches, 66,846; pears, 12,051; pecans, 60,207; plums, 1,039; pomegranates, 1,380; raspberries, 4,409; seed crops, 186,535; strawberries, 8,165; and walnuts, 63,149.

In 1993, 91% of the total 1,129,947 pounds was applied to grape, citrus, fruit and nut crops, and right-of-ways.

In 1989, 1982, 1976, 1971, and 1966, approx. 3.964X10+6, 3.975X10+6, 3.253X10+6, 1.738X10+6, and 1.93X10+5 lbs. AI/yr, respectively, were used in U.S. agriculture.

For more Consumption Patterns (Complete) data for SIMAZINE (6 total), please visit the HSDB record page.

MILLER SIMAZINE 4% GRANULES HERBICIDE Active Ingredient 4.00% Simazine

PRINCEP 4L HERBICIDE Active Ingredient 41.90% Simazine: SIMAZINE TECHNICAL Active Ingredient 97.00% Simazine; PRINCEP CALIBER 90 HERBICIDE Active Ingredient 90.00% Simazine

ALLPRO BARACIDE 5PS PELLETED HERBICIDE Active Ingredients 40.00% Sodium metaborate (NaBO2), 39.80% Sodium chlorate, 5.00% Prometon, and 0.7600% Simazine

ALCO SIMAZINE Active Ingredient 4.00% Simazine; 101 BRAND SIMAZINE 4G GRANULAR HERBICIDE Active Ingredient 4.00% Simazine

For more Formulations/Preparations (Complete) data for SIMAZINE (18 total), please visit the HSDB record page.

Pesticides -> Herbicides -> Triazine herbicides -> Chlorotriazine herbicides

Environmental transformation -> Pesticides (parent, predecessor)

Herbicides

HERBICIDES

1,3,5-Triazine-2,4-diamine, 6-chloro-N2,N4-diethyl-: ACTIVE

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

End-use products containing simazine may be applied on the ground by broadcast across an area, as a spot treatment, or in rows, which is also referred to as band treatment. Some products can also be applied by aerial broadcast. ... For agricultural uses, the maximum use or application rates range from 1 to 9.6 pounds active ingredient per acre (lbs ai/A). For noncrop land, maximum application rates are 40 lbs ai/A, and for use specifically on turfgrass, 4 lbs ai/ A.

COMPATIBLE WITH MOST OTHER PESTICIDES & FERTILIZERS WHEN USED @ NORMAL RATES.

LIMITED STUDIES HAVE SHOWN SOME MINOR FUNGICIDAL & NEMATOCIDAL ACTIVITY BUT NO INSECTICIDAL ACTIVITY.

Applications of either sprays or granules should be made on bare soil prior to weed emergence. It also may be applied prior to planting for many crops. Simazine has little or no foliar activity & must be absorbed by plant roots. Under dry conditions, a shallow incorporation may increase the degree of weed control. For aquatic use such as in recreational or farm ponds, application may be made from several points in the pond. Natural water movement will disperse simazine.