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NITROSOETHYLURETHANE is a nitrated carbamate ester derivative. Carbamates are chemically similar to, but more reactive than amides. Like amides they form polymers such as polyurethane resins. Carbamates are incompatible with strong acids and bases, and especially incompatible with strong reducing agents such as hydrides. Flammable gaseous hydrogen is produced by the combination of active metals or nitrides with carbamates. Strongly oxidizing acids, peroxides, and hydroperoxides are incompatible with carbamates.

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.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 80(SRC), determined from a structure estimation method(2), indicates that N-ethyl-N-nitrosourethane is expected to have high mobility in soil(SRC). Volatilization of N-ethyl-N-nitrosourethane from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.9X10-8 atm-cu m/mole(SRC), using a fragment constant estimation method(3). N-Ethyl-N-nitrosourethane is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 0.03 mm Hg at 25 °C, determined from a fragment constant method(4). Biodegradation data in soil were not available(SRC, 2010).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 80(SRC), determined from a structure estimation method(2), indicates that N-ethyl-N-nitrosourethane is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 1.9X10-8 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of 6(SRC), from an estimated log Kow of 1.71(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Hydrolysis may be an important environmental fate process based on a rate of 0.029/hour under neutral conditions and 2900/M/hour under basic conditions for analogous N-nitroso-N-methylurethane(8). Biodegradation data in water were not available(SRC, 2010).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), N-ethyl-N-nitrosourethane, which has an estimated vapor pressure of 0.03 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase N-ethyl-N-nitrosourethane 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 28 hours(SRC), calculated from its rate constant of 1.3X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). N-Ethyl-N-nitrosourethane contains chromophores that absorb at wavelengths >290 nm(4) and therefore may be susceptible to direct photolysis by sunlight(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of N-ethyl-N-nitrosourethane can be estimated to be 80(SRC). According to a classification scheme(2), this estimated Koc value suggests that N-ethyl-N-nitrosourethane is expected to have high mobility in soil.

An estimated BCF of 6 was calculated in fish for N-ethyl-N-nitrosourethane(SRC), using an estimated log Kow of 1.71(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Henry's Law constant for N-ethyl-N-nitrosourethane is estimated as 1.9X10-8 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that N-ethyl-N-nitrosourethane is expected to be essentially nonvolatile from water surfaces(2). N-Ethyl-N-nitrosourethane is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 0.03 mm Hg(SRC), determined from a fragment constant method(3).

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ Post-initiation dose-dependent effects of ... 1-O-hexyl-2, 3, 5-trimethylhydroquinone (HTHQ) ... on the development of forestomach and tongue tumors were investigated in male F344 rats. Groups of 22 rats were treated with 0.01% ethylnitrosourethane (ENUR) as an initiator in the drinking water for 4 weeks, then placed on diet containing 1.0%, 0.5%, 0.25% or 0.125% HTHQ, or basal diet alone for 36 weeks. Further group of 12 rats each were similarly treated with the different doses of HTHQ or given basal diet alone for 36 weeks without prior ENUR treatment. All animals were killed at week 40. Tongue papillary hyperplasia and papillomas tended to be increased in the groups treated with ENUR followed by 0.5-0.125% HTHQ, though there was no effect at the highest dose, in line with increased bromodeoxyuridine labeling indices. In the forestomach, the incidences of papillomas and carcinomas were also significantly elevated only in the group treated with ENUR followed by 0.125% HTHQ. Without ENUR pretreatment, papillary hyperplasia was found in the 1-0.125% HTHQ groups and the labeling index was also increased, though without clear dose dependence. The results indicate that HTHQ may have very weak or weak promotion potential for tongue and forestomach carcinogenesis, but that both minimum and maximum thresholds for active dose levels may exist.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ A dose-response study on the carcinogenicity of N-ethyl-N-nitrosourethane (ENUR) was undertaken to examine its effect at low doses. Six-week-old female F344 rats were divided into 5 groups, each consisting of 40 animals. ENUR was dissolved in distilled water at dose levels of 0 (control), 0.15, 0.6, 2.5 and 10 ppm, and rats were given these solutions ad libitum for 2 years. Significant increase of the total tumor incidences and shortening of the mean survival times were observed in groups given 2.5 and 10 ppm ENUR. In groups given 0.6 ppm or more ENUR, digestive tract tumors were induced dose-dependently. They were restricted to the upper digestive tract from the oral cavity to the forestomach, and were histologically squamous cell papillomas or carcinomas. Dose-related differences in the location and incidence of these tumors were found ...

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ Groups of female Donryu rats were given solutions of 100, 50, and 25 ppm of 1-ethyl-1-nitrosourethane (ENUR), and of 400, 200, and 100 ppm of 1-amyl-1-nitrosourethane (ANUR) continuously in the drinking water. The incidence of tumors was nearly 100% in all groups treated with ENUR or ANUR, but with both chemicals the rats showed dose-dependent mean survival times. In the groups treated with ENUR, tumors were most frequent in the upper digestive tract and duodenum, whereas in groups given ANUR tumors were induced only in the upper digestive tract, with none in the duodenum. Tumors of the forestomach were more frequent than those of the esophagus and oral cavity and/or pharynx in groups treated with ENUR. In contrast, the target organs of ANUR were the oral cavity and/or pharynx, and the esophagus, rather than the forestomach ...

/GENOTOXICITY/ The effects of the 3 related compounds ethylnitrosourea (ENU), methylnitrosourea (MNU), and ethylnitrosourethane (NEC) were studied in the mouse spot test. ENU induces a large number of recessive spots (RS) and, due to its low toxicity, can be applied at relatively high doses. This combination of properties makes it the most efficient spot-test mutagen, as shown in a comparison with 16 other chemicals, even though, on the basis of molarity, it is not the most potent one. The ENU mutation frequency in cells at risk, calculated per locus, per unit of applied dose, is roughly similar for melanocyte precursors (in the spot test) and spermatogonial stem cells (in the specific-locus test). MNU which, due to its high embryotoxicity, could be tested only at a low dose, is clearly mutagenic, and dose extrapolations indicate it to be more potent than ENU. NEC, though it could be tested at higher molarities than ENU, is only weakly mutagenic. The spot test, in addition to mutational data, also yields information on cytotoxicity (white midventral spots), embryotoxicity, and teratogenicity. The toxicity and teratogenicity findings parallel earlier results in the rat. For all endpoints studied. ENU is more effective than NEC. Relative to MNU, ENU is less toxic, less teratogenic, and less mutagenic in the spot test; but it is much more carcinogenic (transplacentally) and more mutagenic in spermatogonia ...

The rate constant for the vapor-phase reaction of N-ethyl-N-nitrosourethane with photochemically-produced hydroxyl radicals has been estimated as 1.3X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 28 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Hydrolysis may be an important environmental fate process based on a rate of 0.029/hour under neutral conditions and 2900/M/hour under basic conditions for analogous N-nitroso-N-methylurethane(2). N-Ethyl-N-nitrosourethane contains chromophores that absorb at wavelengths >290 nm(3) and therefore may be susceptible to direct photolysis by sunlight(SRC).

N-Ethyl-N-nitrosourethane's production and use in cancer research may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 0.03 mm Hg at 25 °C indicates N-ethyl-N-nitrosourethane will exist solely as a vapor in the atmosphere. Vapor-phase N-ethyl-N-nitrosourethane will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 28 hours. N-Ethyl-N-nitrosourethane contains chromophores that absorb at wavelengths >290 nm and therefore may be susceptible to direct photolysis by sunlight. If released to soil, N-ethyl-N-nitrosourethane is expected to have high mobility based upon an estimated Koc of 80. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 1.9X10-8 atm-cu m/mole. Biodegradation data were not available. If released into water, N-ethyl-N-nitrosourethane is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. An estimated BCF of 6 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis may be an important environmental fate process based on a rate of 0.029/hour under neutral conditions and 2900/M/hour under basic conditions for analogous N-nitroso-N-methylurethane. Occupational exposure to N-ethyl-N-nitrosourethane may occur through dermal contact with this compound at workplaces where N-ethyl-N-nitrosourethane is produced or used. (SRC)

/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Isocyanates, aliphatic thiocyanates, and related compounds/

/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Monitor for seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patent can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . /Isocyanates, aliphatic thiocyanates, and related compounds/

/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Treat exposure to Lethane 60 Lethane 384, Thanite, methyl, ethyl, or isopropyl thiocyanates with the cyanide antidote kit. ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Isocyanates, aliphatic thiocyanates, and related compounds/

/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Nitrates, nitrites, and related compounds/

For more Antidote and Emergency Treatment (Complete) data for N-Ethyl-N-nitrosourethane (6 total), please visit the HSDB record page.