Imidazolidin-2-thion

Hazardous Air Pollutants (HAPs)

Nitrogen Compounds -> Thiourea Compounds

Carcinogens

Pesticide -> EPA IRIS

Environmental transformation -> Pesticide transformation products (metabolite, successor)

log Kow = -0.66

-0.66 (calculated)

-0.66

Needles, prisms from alcohol or amyl alcohol

White to pale-green crystals

1 to 5 mg/mL at 64 °F (NTP, 1992)

Soluble in ethanol; slightly soluble in dimethyl sulfoxide; insoluble in ethyl ether, benzene, chloroform

Moderately soluble in methanol, ethanol, ethylene glycol, pyridine; insoluble in acetone, ether, chloroform, benzene, ligroin

Soluble in ethanol; insoluble in ethyl ether and benzene.

Slightly soluble at room temperature in methanol, ethanol, acetic acid, naphtha.

2 g/100 mL water at 30 °C; 9 g/100 mL water at 60 °C; 44 g/100 mL water at 90 °C

486 °F (NTP, 1992)

486 °F

252 °C

486 °F

486 °F

446 to 595 °F at 760 mmHg (NIOSH, 2024)

446-595 °F

446-595 °F

When heated to decomposition it emits very toxic fumes of /nitroxides/ and /sulfoxides/.

Photolytic degradation is a major pathway for ETU in water, and is enhanced by the presence of photosensitizers such as chlorophyll.

Danger

H302: Harmful if swallowed [Warning Acute toxicity, oral]

P203, P264, P270, P280, P301+P317, P318, P330, P405, and P501 (click each P-code to see the statement)

Danger

H302 (84.5%): Harmful if swallowed [Warning Acute toxicity, oral]

P203, P260, P264, P270, P273, P280, P301+P317, P302+P352, P317, P318, P319, P321, P330, P362+P364, P405, and P501 (click each P-code to see the statement)

Chemical: 2-Imidazolidinethione

Hazard Traits - Carcinogenicity; Developmental Toxicity; Reproductive Toxicity

Commission Regulation No 844/2012

2-Imidazolidinethione is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of 2-Imidazolidinethione are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

Status: Active Update: 20-08-2020 https://echa.europa.eu/registration-dossier/-/registered-dossier/13536

Substance: Imidazolidine-2-thione (2-imidazoline-2-thiol)

This chemical is combustible. (NTP, 1992)

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

Ethylene thiourea is used in the rubber industry and in the production of some fungicides. No information is available on the acute (short-term) or chronic (long-term) effects of ethylene thiourea in humans. In rodents chronically exposed to ethylene thiourea in their diet, effects on the thyroid have been observed. Ethylene thiourea has been shown to be a potent teratogen (causes birth defects) in rats orally or dermally exposed. A study of female workers occupationally exposed to ethylene thiourea did not report an increased incidence of thyroid cancer. In a study by the National Toxicology Program (NTP), an increased incidence of thyroid tumors in rats, and thyroid, liver, and pituitary gland tumors in mice exposed to ethylene thiourea were noted. EPA has classified ethylene thiourea as a Group B2, probable human carcinogen.

Potential skin sensitizer; [Marks, p. 240] [Allergic contact dermatitis from ethylene thiourea. Bruze M, Fregert S. Contact Dermatitis 1983;3:208-12] Ethylenethiourea is a common contaminant of ethylene bisdithiocarbamates (Ferbam, Mancozeb, Maneb, Metiram, Nabam, Thiram, Vapam, Ziram, and Zineb). It causes birth defects in high-dose reproductive studies of experimental animals. [Frazier, p. 230-2] May have effects on the thyroid gland and liver; [ICSC] An eye irritant; [CAMEO]

National Toxicology Program. Eleventh Report on Carcinogens (2005). The Report on Carcinogens is an informational scientific and public health document that identifies and discusses substances (including agents, mixtures, or exposure circumstances) that may pose a carcinogenic hazard to human health. Ethylene Thiourea (96-45-7) is listed as reasonably anticipated to be a human carcinogen.[Available from, as of July 31, 2009: http://ntp.niehs.nih.gov/ntp/roc/eleventh/profiles/s086etu.pdf]

DHHS/NTP; Toxicology and Carcinogenesis Studies of Ethylene thiourea (CAS No. 96-45-7) in F344/N Rats and B6C3F1 Mice (Feed Studies); Technical Report Series No. 388 (1992) NIH Publication No. 92-2843[Available from, as of March 3, 2010: http://ntp.niehs.nih.gov/ntp/htdocs/LT_rpts/tr388.pdf]

WHO/IARC; IARC Monographs on the Evaluation of the Carcinogenic Risks to Humans; Vols. 1 to 42, Supplement 7. Overall Evaluations of Carcinogenicity: An Updating of IARC Monographs (1987). IARC Monographs provide critical reviews of data on carcinogenicity for agents to which humans are known to be exposed and on specific exposure situations.[Available from, as of February 3, 2010: http://monographs.iarc.fr/ENG/Monographs/suppl7/index.php]

WHO/IARC; IARC Monographs on the Evaluation of the Carcinogenic Risks to Humans. Vol. 79. Some Thyrotropic Agents (2001). IARC Monographs provide critical reviews of data on carcinogenicity for agents to which humans are known to be exposed and on specific exposure situations.[Available from, as of February 3, 2010: http://monographs.iarc.fr/ENG/Monographs/vol79/index.php]

For more Special Reports (Complete) data for Ethylene thiourea (6 total), please visit the HSDB record page.

U116; As stipulated in 40 CFR 261.33, when ethylenethiourea, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to Federal and/or State hazardous waste regulations. Also defined as a hazardous waste is any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5).

ETHYLENE THIOUREA may be sensitive to prolonged exposure to light. Incompatible with acids, diazo and azo compounds, halocarbons, isocyanates, aldehydes, alkali metals, nitrides, hydrides, and other strong reducing agents. Reactions with these materials generate heat and in many cases hydrogen gas. May react with acids to liberate hydrogen sulfide.

Listed as a hazardous air pollutant (HAP) generally known or suspected to cause serious health problems. The Clean Air Act, as amended in 1990, directs EPA to set standards requiring major sources to sharply reduce routine emissions of toxic pollutants. EPA is required to establish and phase in specific performance based standards for all air emission sources that emit one or more of the listed pollutants. Ethylene thiourea is included on this list.

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

Use water spray, powder, foam, carbon dioxide.

Fresh air.

Rinse skin with plenty of water or shower.

Rinse with plenty of water (remove contact lenses if easily possible).

Rinse mouth. Seek medical attention if you feel unwell.

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.

(General first aid procedures)

Use dry chemical, carbon dioxide, water spray, or foam extinguishers ... 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.

Store in tightly closed containers in a cool, well ventilated area away from strong oxidizers, acids, acid anhydrides, acrolein. Store in a refrigerator or a cool, dry place. A regulated marked area should be established where this chemical is handled, used, or stored ...

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.

Spill Handling: Evacuate persons not wearing protective equipment from area of spill or leak until cleanup is complete. Remove all ignition sources. Dampen spilled material with water to avoid dust. Collect powdered material in the most convenient and safe manner and deposit in sealed containers. Ventilate area of spill or leak 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.

Work areas, fixtures, equipment, etc, contaminated by ETU spills should be cleaned promptly. ETU powder on floors should be blotted with absorbing clay which, in turn, may be removed with a sweeping compound. An alkaline solution of hypochlorite will oxidize ETU into ethylene urea. Thus, a one to ten dilution of commercially available 5% hypochlorite solutions may be used to mop up areas contaminated with ETU.

SMALL SPILLS AND LEAKAGE: If a spill of this chemical occurs, FIRST REMOVE ALL SOURCES OF IGNITION, then you should dampen the solid spill material with acetone and transfer the dampened material to a suitable container. Use absorbent paper dampened with acetone to pick up any remaining material. Seal your contaminated clothing and the absorbent paper in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with acetone 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.

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U116, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

A potential candidate for rotary kiln incineration at a temperature range of 820 to 1,600 °C and residence times of seconds for liquids and gases, and hours for solids. A potential candidate for fluidized bed incineration at a temperature range of 450 to 980 °C and residence times of seconds for liquids and gases, and longer for solids.

Incineration: Proper incineration in a furnace with afterburner and scrubber.

Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Sweep spilled substance into covered sealable containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits 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.

SRP: Contaminated protective clothing should be segregated in a manner that results in no direct personal contact by personnel who handle, dispose of, or clean the clothing. Quality assurance procedures to confirm the efficacy of the cleaning procedures should be implemented prior to the decontaminated protective clothing being returned for reuse by the workers. Contaminated clothing (including shoes/socks) should not be taken home at end of shift, but should remain at employee's place of work for cleaning.

The most effective control of ethylene thiourea, where feasible, is at the source of contamination by enclosure of the operation and/or local exhaust ventilation. ... The process or operation should be enclosed with a slight vacuum so that any leakage will result in the flow of air into the enclosure. The next most effective means of control would be a well designed local exhaust ventilation system that physically encloses the process as much as possible, with sufficient capture velocity to keep the contaminant from entering the work atmosphere. To ensure that ventilation equipment is working properly, effectiveness (eg, air velocity, static pressure, or air volume) should be checked at least every 3 mo. System effectiveness should be checked soon after any change in production, process, or control ... A 3rd alternative is the isolation of employees ... by use of automated equipment operated by personnel observing from a closed control booth or room.

Employees working in areas where ETU is manufactured, processed, handled, or stored should wash their hands before eating, drinking, smoking, or using rest room facilities during the work shift. No food or beverages should be stored, prepared, or consumed in areas where ETU is manufactured, processed, handled, or stored. Contaminated clothing should be removed before entering areas where food or beverages are consumed. Smoking should be prohibited in areas where ETU is manufactured, processed, handled, or stored in unsealed containers. Employees should shower or bathe and change clothing after the workday if any possible dermal exposure could have occurred. In many secondary uses of ETU, the dust hazard may be eliminated by the substitution of sheets or pellets of ETU (dispersed in a plastic material) for powdered ETU when it is used as a direct additive.

For more Preventive Measures (Complete) data for Ethylene thiourea (8 total), please visit the HSDB record page.

The mean levels of ethylene thiourea in urine were 1.5 and 0.9 ug/L for potato and pine nursery workers after the end of the exposure, respectively. The levels of ethylene thiourea in urine declined very slowly during the observation period. The range of ethylene thiourea levels in urine of potato field inspectors was 0-4.5 ug/L (mean 0.12 and standard error of the mean 0.13 ug/L)(1).

Average ethylene thiourea concentrations in urine of factory workers who prepared commercial formulations of mancozeb and dimethoate ranged from 4.4 to 174.8 ug/g creatine(1).

When the mutagenicity of ETU was assayed before and after nitrosation with sodium nitrite under acid conditions, nitrosation was found to cause a 160-fold increase in the number of revertant colonies of S. typhimurium TA 1535 ... The interactive mutagenicity of ETU and nitrite was also found in the mouse dominant lethal test ... However, no dominant-lethal mutations were induced in a group of mice treated with 30 mg ETU plus 10 mg nitrite/kg bw. A large increase in pre-implantation losses was noted 5 and 6 weeks after completing a 5-day treatment of males with a combined oral dose of 150 mg ETU/kg and 50 mg sodium nitrite/kg bw.

Administered alone /in rats/, sodium nitrite did not produce any teratogenic response in full-term fetuses, whereas ethylene thiourea produced a high incidence of various anomalies. However, the combined dosing resulted in the elimination of almost all the anomalies.

The effects of oral administration of ethylenethiourea (ETU) and sodium nitrite on endometrial adenocarcinoma development was investigated in female Donryu rats. At 10 week of age, groups 1 and 3 received a single dose of polyethylene glycol (PEG) into the uterine cavity, while groups 2 and 4 were given N-ethyl-N-nitrosourea (ENU) (15 mg/kg) solution, dissolved in PEG, in the same manner. ETU (80 mg/kg) and sodium nitrite (56 mg/kg) dissolved in distilled water were orally given to animals in groups 3 and 4 once a week from 11 to 51 weeks of age. Groups 1 and 2 received the vehicle alone. At termination (52 weeks of age), endometrial adenocarcinomas were observed in 29, 13 and 57% of rats in groups 2, 3 and 4, respectively, but not in group 1. Persistent estrus appeared earlier in groups 3 and 4 than in group 1. In groups 3 and 4, hyperplastic and neoplastic lesions of the digestive tract, especially the forestomach, were also observed. The results indicate that N-nitroso ETU formed in the stomach by concurrent oral administration of ETU and sodium nitrite, itself induces endometrial adenocarcinomas by its mutagenic action, as well as promoting their development after ENU-initiation, presumably by influencing the hormonal balance.

Aging effects on the susceptibility to chemical endometrial carcinogenesis were investigated in ICR female mice. The animals were divided into 3 groups of different ages: 1 month (young), 6 months (middle), and 12 months (old) at initiation of treatment. They received weekly oral administration of mixture of ETU (100 mg/kg body weight) and sodium nitrite (70 mg/kg body weight) for 6 months followed by a withdrawal period of 3 months. All animals were subjected to histopathology. The incidence of endometrial adenocarcinomas was highest in the middle age group (8/20), secondary in the old age group (4/20), and lowest in the young group (1/20). The incidence of atypical glandular hyperplasia, a precursor lesion of the tumor, was also higher in the middle age group. The endometrial adenocarcinomas showed morphological similarities among all age groups and the nuclei of tumor cells lost almost all staining reactivity to estrogen receptors. The labeling indices with bromodeoxyuridine (BrdU) were notably higher in the old age group than in the young and middle age groups. A further investigation on the aging process of female genital organs in control mice revealed that their senility seemed to be preceded by the formation of ovarian cysts which first appeared at 6 months of age with a concomitant elevation of plasma 17 beta-estradiol level. These results indicate that the susceptibility of the mouse endometrium to the carcinogenic effects of N-nitroso ETU could be closely linked with the stage of aging process of the genital organs and it appears to be most susceptible when initiated at around 6 months of age. However, the mitotic activity of neoplastic endometrial glandular cells seems to be higher in older mice than younger ones.

For more Interactions (Complete) data for Ethylene thiourea (6 total), please visit the HSDB record page.

Endocrine

Eyes, skin, thyroid, reproductive system

EC50; Species: Chlorella pyrenoidosa (Green algae, 10+8 cells/100 mL); Conditions: freshwater, static, 20 °C; Concentration: 6600000 ug/L for 96 hr; Effect: growth, general /99% purity/

LC50; Species: Xenopus laevis (African clawed frog, 10-12 stage embryo); Conditions: freshwater, culture medium application, 22 °C; Concentration: 100000 ug/L for 10 days /100% purity/

LC50; Species: Daphnia magna (Water flea); Conditions: freshwater, renewal; Concentration: 26400 ug/L for 48 hr (95% confidence interval: 21600-32200 ug/L) /99% purity/

LC50; Species: Daphnia magna (Water flea, age <24 hr); Conditions: freshwater, renewal, 20 °C; Concentration: 18000 ug/L for 21 days (95% confidence interval: 10000-32000 ug/L) /> or =99% purity/

For more Ecotoxicity Values (Complete) data for Ethylene thiourea (7 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 13(SRC), determined from a structure estimation method(2), indicates that ethylene thiourea is expected to have very high mobility in soil(SRC). Volatilization of ethylene thiourea from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 3.4X10-7 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Ethylene thiourea is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.0X10-6 mm Hg(SRC), determined from a fragment constant method(4). Utilizing the Japanese MITI test, 0% of the theoretical BOD was reached in 4 weeks indicating that biodegradation is not an important environmental fate process(5). However, other studies showed ethylene thiourea to be biodegradable in aerobic soil samples from a sandy locality in western Jylland, Denmark at a concentration 125 ug/L incubated in the dark at 23 °C for 120 days(6).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 13(SRC), determined from a structure estimation method(2), indicates that ethylene thiourea is not 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 3.4X10-7 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), BCFs of <1.8 measured in carp (Cyprinus carpio)(6), suggest bioconcentration in aquatic organisms is low(SRC). Ethylene thiourea was found to be extremely stable to hydrolysis over the pH range 5-9 at 90 °C for a 3 month period(7). Utilizing the Japanese MITI test, 0% of the theoretical BOD was reached in 4 weeks indicating that biodegradation is not an important environmental fate process(6).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), ethylene thiourea, which has an estimated vapor pressure of 2.0X10-6 mm Hg at 25 °C(SRC) determined from a fragment constant method(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase ethylene thiourea is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 3 hours(SRC), calculated from its rate constant of 1.4X10-10 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase ethylene thiourea may be removed from the air by wet or dry deposition(SRC). Aquatic photolysis studies indicate that ethylene thiourea undergoes photolysis in photosensitized, deionized water and sterilized natural waters(4). It was decomposed in 6 of 7 natural waters when exposed to light, but did not decompose in the dark(5). Therefore, ethylene thiourea may be susceptible to photolysis in the environment(SRC).

Of 167 food samples analyzed (fruits, vegetables, grain products), which are produced in or imported by Canada, 56 contained detectable levels of ethylene thiourea with concentrations ranging from 0.01-0.150 ppm and a mean concentration of about 0.02 ppm(1). Commercial tomato products (whole pack, paste, juice, soup, ketchup) contained residues ranging from <0.01-0.03 ppm(2). Of 11 commercial grape products (jelly, jam, concentrates, drink, wine), 8 contained detectable levels of ethylene thiourea with positive concentrations ranging from <0.01-0.06 ppm(3). Commercial tomato products purchased at random from grocery stores in Wilmington, DE contained no ethylene thiourea above the detection limit of 0.05 ppm(4). Commercial apples from a 1974 crop contained residues of less than or equal to 0.01 ppm(5). Levels of 0.01-0.21 ppm were detected in 282 samples of commercial food commodities in Japan(6). Ethylene thiourea was present in 13 of 55 samples of fresh fruit and vegetables collected in Sassari, Italy with concentrations ranging from 0.007 to 0.43 ppm(7).

Ethylene thiourea was tested in the 30% of samples of fruits and vegetables from a Sydney, Australia wholesale market which tested positive for residues of ethylenebisdithiocarbamate; residues were below the detection limit of <0.02 mg/kg(1). Some ethylene thiourea traces have been found in wine but at <0.05 ppm(2). Ethylene thiourea was detected at a range of 0.02 to 0.01 mg/kg over 21 days in Bartlett pears after spraying with the fungicide zineb(3). Boiling treated pears resulted in a 3-6% conversion of ethylenebisdithiocarbamate to ethylene thiourea. It was not detected in commercially canned pears but was present in four of six samples of baby food pear puree(3). After spraying with ethylenebis(dithiocarbamates) formulations at recommended rates, ethylene thiourea was detected at levels <0.05 ppm on tomatoes, monitored 1973 to 1977(4). Boiling of some products demonstrated additional ethylene thiourea formation(4). Residues in tomato juice and whole pack products, prepared from treated tomatoes in the first 3 days after application had a concentration range <0.01-0.17 ppm(4).

The substance can be absorbed into the body by inhalation and through the skin.

inhalation, ingestion, skin and/or eye contact

/AQUATIC SPECIES/ Xenopus laevis embryos at yolk plug stage (Nieuoop and Faber stages 10-12) were exposed to various concentrations of fresh and 1-7 wk old nabam solutions, ethylene thiourea, ethylene diamine, methyl isothiocyanate, thiocyanate, and combinations of some of these substances. thiocyanate, ethylene thiourea, and ethylene diamine (100-10,000 ug/l) were neither toxic nor teratogenic.

/AQUATIC SPECIES/ Ethylene thiourea, a degradation product of a widely used group of bisdithiocarbamate fungicides, is a potent teratogen in frog (Microhyla ornata) embryos. Embryos treated from the gastrula stage onwards for 24 hr (10-40 ppm) developed edema, an abnormal and wavy notochord, and other defects such as incomplete pigmentation.

/AQUATIC SPECIES/ ... This study examined histological and molecular changes in the thyroid of Xenopus laevis tadpoles during a 12-day treatment with ... 50 mg/L ethylenethiourea (ETU). Inhibition of thyroid hormone (TH) synthesis by ... ETU was evident from developmental retardation, reduced expression of TH-regulated genes and up-regulation of tshb-A mRNA. Thyroid histopathology revealed goiters with strikingly different follicular morphologies following ... ETU treatment. Using real-time polymerase chain reaction (PCR), ... thyroids sampled on day 12 /were evaluated/ for differential expression of 60 candidate genes. Further temporal analyses were performed for a subset of 14 genes. Relative to the control, ... ETU treatment modulated the expression of ... 49 transcripts ... .

/AQUATIC SPECIES/ In the present study, a test protocol for a Xenopus metamorphosis assay (XEMA) was developed and its interlaboratory transferability was evaluated in an informal ring test with six laboratories participating. In the Xenopus metamorphosis assay (XEMA) test, exposure of Xenopus laevis tadpoles was initiated at stages 48 to 50 and continued for 28 d. Development and growth of tadpoles were assessed by means of developmental stage and whole body length determinations, respectively. ... Five different ethylene thiourea (ETU) concentrations (5, 10, 25, 50, and 100 mg/L) were tested and a concentration-dependent inhibition of metamorphosis was observed /but/ tadpole survival and ... growth /were unaffected/...

/AQUATIC SPECIES/ Isolated /Daphnia magna/ eggs were cultured in the presence of ethylenethiourea during the period of embryonic development for 3 days. Treatment with ethylenethiourea induced morphological abnormalities in the cladoceran carapace. Parthenogenetic eggs of Cladocera are genotypically identical, which makes them useful biological materials for a toxicity test on aquatic pollutants.

...Treatment of kale and lettuce with maneb (which contained some ethylenethiourea) at a rate of 1.09 kg active ingredient per acre resulted in initial residues of 0.6 mg/kg ethylenethiourea, which decreased to undetectable levels within seven days after application.

residues of ETU monitored in tomatoes after application of several ebdc formulations from 1973-1977. After spraying with EBDC at recommended rates, ETU was detected at levels less than 0.05 ppm on tomatoes. Boiling of some products demonstrated additional ETU formation. Residues in tomato juice and whole pack products, prepared from treated tomatoes in 1st 3 days after application, ranged from less than 0.01-0.17 ppm.

U116; As stipulated in 40 CFR 261.33, when ethylenethiourea, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to Federal and/or State hazardous waste regulations. Also defined as a hazardous waste is any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5).

Listed as a hazardous air pollutant (HAP) generally known or suspected to cause serious health problems. The Clean Air Act, as amended in 1990, directs EPA to set standards requiring major sources to sharply reduce routine emissions of toxic pollutants. EPA is required to establish and phase in specific performance based standards for all air emission sources that emit one or more of the listed pollutants. Ethylene thiourea is included on this list.

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 10 lb or 4.54 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).

(FL) FLORIDA 15 ug/l

(ME) MAINE 0.6 ug/l

Ethylenebisdithiocarbamates (EBDCs) maneb and zineb are widely used fungicides the final metabolite of which is ethylenethiourea (ETU). EBDCs distort the humoral activity of the thyroid gland, and ETU is especially active in this respect. Male Wistar rats were exposed either to exogenous (100 ng ip) or endogenous (+4 degrees C) TRH stimulation. ETU (100-500 mg/kg i.p.) caused no changes in serum TSH levels whereas zineb (70-500 mg/kg ip) significantly decreased the bursts induced by cold or exogenous TRH. Maneb (20-200 mg/kg ip) significantly decreased the cold-induced TSH response while it had no effect on the TRH-stimulated TSH secretion. None of the agents caused significant changes in serum T3 or T4 levels. It seems that maneb, and zineb, but not ETU, inhibit rat TSH secretion through an action on the endogenous TRH at the hypothalamic or pituitary level. The mechanism behind this action may be the inhibition of dopamine-beta-hydroxylase.

The biochemical changes induced by antithyroid drugs include reduced production of thyroid hormones (T3 and T4), followed by increased production of TSH in response to low thyroid hormone levels in the blood. Pathological changes in the thyroid gland begin with diffuse microfollicular hyperplasia and are followed by diffuse and nodular hyperplasia and later by nodular hyperplasia with papillary and cystic changes induced by the TSH. If hyperstimulation of the thyroid by TSH is severe and prolonged, it provides conditions conducive to the formation of tumors. Antithyroid drugs can inhibit T4 production in various ways. The chemical similarity of ETU to thiourea and thiouracil suggests that ETU acts by blocking the iodination of thyroxine precursors, thus reducing the synthesis of the thyroid hormones. Iodide peroxidase catalyses the iodination of tyrosine and the coupling of the resultant iodotyrosyl residues to produce the active hormones T3 and T4 ... ETU /was found to/ inhibit iodide peroxidase in vitro. The resulting decreased level of thyroid hormones causes stimulatory feedback of the pituitary gland and consequently an increased release of TSH ... The influence of ETU in pregnant hypothyroid and euthyroid rats /was studied/ to determine whether ETU teratogenicity occurs as a result of altered maternal thyroid function. Doses of 40 mg ETU/kg bw, administered on days 7 - 15 of gestation, resulted in 84 - 100% of the fetuses in all treated groups being malformed, regardless of the thyroid status of the dams ... /It was/ concluded that the thyroid status of the mother is not of importance in causing teratogenic effects ... The effects of feeding rats 125 - 625 mg ETU/kg diet for 2 - 12 weeks, which included thyroid hyperplasia and dose related suppression of serum T3 and T4 (with corresponding TSH elevation), were reversible within 22 weeks of placing on control diets. Long-term studies using ETU showed significantly increased thyroid/bw ratios in rats fed 125, 250, or 500 mg/kg diet for periods of up to 2 years ... This effect was not reversed in rats placed on a control diet after 66 weeks of continuous exposure to 5 - 500 mg ETU/kg diet. It is likely that by that time the thyroid was severely damaged ... Decreased levels of serum thyroid hormones and increased thyroid weights were reversed in Sprague Dawley rats fed diets containing 0, 75, 100, or 150 mg ETU/kg diet for 7 weeks. The reversibility of microscopic changes in the thyroids of male rats exposed to ETU was /also/ studied. The rats were fed diets containing 75 or 150 mg ETU/kg diet for 7 - 82 weeks and then returned to a control diet for periods ranging from 2 to 42 weeks. The severity and extent of reversibility of thyroid hyperplasia were found to depend on the duration of exposure to ETU. Above a certain threshold, hyperplasia did not regress significantly. Numerous studies with ETU suggest that the rat is more sensitive than other species to the effects of the thyroid. A recent study with propylthiouracil, a thyroid inhibitor with a mode of action similar to that of ETU, has confirmed that monkeys are much less sensitive than rats. The sensitivity difference was not quantified in vivo, but in an in vitro study, the concentration of inhibitor required to produce the same level of thyroid peroxidase inhibition was approximately 100 times greater for monkey enzyme than it was for rat enzyme ...

ETU and its metabolites have been found to have a half-life of about 28 hr in monkeys, 9 - 10 hr in rats, and 5 hr in mice ...

240 mg/kg were administered to pregnant rats and mice by stomach tube. Maternal and fetal tissue levels were similar at 3 hr post treatment; thereafter mouse (maternal and fetus) showed less ETU than rat. /Half-life/ of elimination from maternal blood was 9.4 hr for rat and 5.5 hr for mouse.

The metabolic decomposition of EBDCs in mammals is complex and results in the formation of carbon disulfide, EDA, a few ethylene bisthiuram disulfides, hydrogen sulfide, ethylene bisthiocyanate, and ETU. The latter is further broken down to moieties that are incorporated into compounds such as oxalic acid, glycine, urea, and lactose. /Dithiocarbamate pesticides/

After treating plants with dithiocarbamates, a large number of metabolites are found, including ETU, EU, imidazole derivatives, diisothiocyanates, diamines, disulfides, and other metabolites that are still unknown. /Dithiocarbamate pesticides/

The various metal derivatives of ethylene bisdithiocarbamic acid appear to be converted in the soil to /5,6-dihydro-3 H-imidazo [2,1-C]-1,2,4-dithiazole-3-thione/ (DIDT), ETU, carbon disulfide, hydrogen sulfide, and carbonyl sulfide ... The conversion by soil bacteria and fungi of DIDT into ETU has been demonstrated ... Even though ETU is slowly converted into EU in soil, pure cultures of soil bacteria and fungi were unable to effect this transformation. /Dithiocarbamate pesticides/

ETU is broken down to ethylene diamine (EDA), urea, carbon dioxide, or oxalic acid, or is transformed to imidazole derivatives in mammals, plants, and the environment.

For more Metabolism/Metabolites (Complete) data for Ethylene thiourea (12 total), please visit the HSDB record page.

Dithiocarbamates and their metabolic products /including ETU/ are found in certain organs, such as the liver, kidneys, and, especially, the thyroid gland, but accumulation of these compounds does not take place because of their rapid metabolism. /Dithiocarbamate pesticides/

ETU is rapidly absorbed, metabolized, and excreted in mammals. Up to 90% is eliminated via the urine and only a small amount via the feces. Distribution of ETU in the body appears to be fairly uniform with the exception of a relative accumulation in the thyroid.

ETU is rapidly absorbed from the gastrointestinal tract and cleared from the body in all the mammalian species that have been tested. After only 5 min, ETU appeared in the blood of rats administered an oral dose of 100 mg (14)C-ETU/kg bw. Within 48 hr, 82 - 99% of an oral dose was eliminated via the urine and about 3% via the feces ... /Another study found/ approximately 70% was eliminated in the urine and 1% in the feces. Comparable results were found for mice while in monkeys, 55% was eliminated via the urine within 48 hr and less than 1.5% via the feces ...

To study the accumulation and elimination of radioactivity by the thyroid gland of rats dosed with (14)C-ETU, dose levels of 2 and 200 ug labeled ETU were administered daily for 14 days. In another study, rats were dosed with 0, 0.1, 1, 10, 50, or 100 mg (14)C-ETU/kg diet, daily, for 7 days. The first study showed that the concentration of ETU and/or its metabolites in the thyroid is dose-dependent, and the second that the level of (14)C in the thyroid did not increase appreciably when the daily dose was increased above 50 mg/kg diet. Withdrawal of ETU from the diet led to an 80 - 94% reduction in the radioactivity in the thyroid after 17 days ...

For more Absorption, Distribution and Excretion (Complete) data for Ethylene thiourea (13 total), please visit the HSDB record page.

Ethylene thiourea is used as an accelerator in synthetic rubber production and as a curing agent for epichlorohydrin elastomers. Ethylene thiourea is also a component of ethylenebisdithiocarbamate fungicides.

The alkylthioureas are used as rubber accelerators; they are also used in insoles, adhesives, wet suits, detergents, plastics, and textiles. [Marks, p. 240] Used in electroplating baths and in the production of antioxidants, insecticides, fungicides, rubber accelerators, dyes, drugs, and resins; [Hawley]

Textiles (Fiber & Fabric Manufacturing) [Category: Industry]

For ethylene thiourea (USEPA/OPP Pesticide Code: 600016) there are 0 labels match. /SRP: Not registered for current 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./

Ethylene thiourea is used primarily as an accelerator for vulcanizing polychloroprene (neoprene) and polyacrylate rubbers. Neoprene rubbers are used almost exclusively in industrial applications (e.g., for mechanical and automotive products), in wire and cable production, in construction, and in adhesives. Polyacrylate rubbers are used in products such as seals, o-rings, and gaskets for automotive and aircraft applications. Ethylene thiourea is used in the manufacture of ethylenebisdithiocarbamate pesticides, such as amobam, maneb, mancozeb, metiram, nabam, and zineb. Ethylene thiourea is also used in electroplating baths, as an intermediate in antioxidant production, in dyes, pharmaceuticals, and synthetic resins.

... It was found that ETU ... was present in 28 different ethylenebisdithiocarbamate commercial products.

(1984) 18.3 x 10+6 lbs.

(1985) 13.8 x 10+6 lbs

(1977) At least 4.5 X 10+6 g

(1984) 9.25 x 10+5 lbs

(1985) nearly 10.6 x 10 +6 lbs

2023: 100,000 - <250,000 lb

(1977) At least 4.54 X 10+7 g

(1980) Probably > 4.54 X 10+5 g

Production volumes for non-confidential chemicals reported under the Inventory Update Rule. [Table#3394]

Production volume for non-confidential chemicals reported under the 2006 Inventory Update Rule. Chemical: 2-Imidazolidinethione. Aggreated National Production Volume: < 500,000 lbs.

Prepared by the action of ethylenediamine upon carbon disulfide in aqueous alcohol.

Methanol and ethanol have been used as extraction solvents for biological samples, due to the high solubility of ETU in polar solvents. Mixed solvents such as methanol/chloroform ... or methanol/acetone ... have also been employed, and the addition of trichloroacetic acid has been reported to improve recovery with the latter solvent. Sodium ascorbate has also been found effective in ensuring good recovery of ETU ...

Transformation products

Environmental transformation -> Pesticide transformation products (metabolite, successor)

Rubber Product Manufacturing

2-Imidazolidinethione: ACTIVE

Alkyl mercury compounds have been used as seed disinfectants and for fungicides. They have also been used in organic synthesis. /Mercury alkyl compounds/

Most studies have been on manganese salt (Maneb), sodium salt (Nabam), and zinc salt (Zineb)

ETU may be formed during the manufacture of dithiocarbamates ... The average ETU content of 76 lots of mancozeb manufactured at six different locations was 0.07%.

Degradation product of ethylenebisdithiocarbamate fungicides such as mancozeb, maneb, zineb...