1,2-Dihydro-5-nitro-3H-1,2,4-triazol-3-one

130.06228

130.06

213-254-4

119860

0490

White to pale yellow crystalline powder

2933990090

99.3

-0.5

Nitrotriazolone <or> nto appears as a solid or liquid. May explode under prolonged exposure to heat or fire. Primary hazard is blast of an instantaneous explosion, not flying projectiles or fragments.

1.92 g/cm³ @ Temp: Room temp

270-271 °C

240.69°C (rough estimate)

1.917

In water: 17,200 mg /L at 25 °C

3.1X10-8 mm Hg at 25 deg (est)

LD50 orl-rat: >5 g/kg NTIS** DE86-003296

Odorless

Described as a strong acid with pH of 2.35 when in a 0.1M solution

Henry's Law constant = 4.1X10-13 atm-cu m/mol at 25 °C (est)

pKa = 3.76 at 20 °C

Heat capacity: 124.5 J/mol-K at 320 K|Hydroxyl radical reaction rate constant = 1.1X10-12 cu cm/molec-sec at 25 °C (est)

Dust may form an explosive mixture in air.

Amides and Imides

Explosive

The triazoles are a group of highly explosive materials that are sensitive to heat, friction, and impact. Sensitivity varies with the type substitution to the triazole ring. Metal chelated and halogen substitution of the triazol ring make for a particularly heat sensitive material. Azido and nitro derivatives have been employed as high explosives. No matter the derivative these materials should be treated as explosives.

Enthalpy of Combustion: -934.4 kJ/mol (crystal phase)

1.1D

0490

P210, P230, P240, P250, P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P370+P380, P372, P373, P401, P403+P233, P405, P501

H201

SRP: 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 air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

Excerpt from ERG Guide 112 [Explosives* - Division 1.1, 1.2, 1.3 or 1.5]: MAY EXPLODE AND THROW FRAGMENTS 1600 METERS (1 MILE) OR MORE IF FIRE REACHES CARGO. For information on "Compatibility Group" letters, refer to Glossary section. (ERG, 2016)

Excerpt from ERG Guide 112 [Explosives* - Division 1.1, 1.2, 1.3 or 1.5]: CARGO FIRE: DO NOT fight fire when fire reaches cargo! Cargo may EXPLODE! Stop all traffic and clear the area for at least 1600 meters (1 mile) in all directions and let burn. Do not move cargo or vehicle if cargo has been exposed to heat. TIRE OR VEHICLE FIRE: Use plenty of water - FLOOD it! If water is not available, use CO2, dry chemical or dirt. If possible, and WITHOUT RISK, use unmanned hose holders or monitor nozzles from maximum distance to prevent fire from spreading to cargo area. Pay special attention to tire fires as re-ignition may occur. Stand by, at a safe distance, with extinguisher ready for possible re-ignition. (ERG, 2016)

Excerpt from ERG Guide 112 [Explosives* - Division 1.1, 1.2, 1.3 or 1.5]: Isolate spill or leak area immediately for at least 500 meters (1/3 mile) in all directions. LARGE SPILL: Consider initial evacuation for 800 meters (1/2 mile) in all directions. FIRE: If rail car or trailer is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, initiate evacuation including emergency responders for 1600 meters (1 mile) in all directions. (ERG, 2016)

Excerpt from ERG Guide 112 [Explosives* - Division 1.1, 1.2, 1.3 or 1.5]: ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. DO NOT OPERATE RADIO TRANSMITTERS WITHIN 100 METERS (330 FEET) OF ELECTRIC DETONATORS. DO NOT CLEAN-UP OR DISPOSE OF, EXCEPT UNDER SUPERVISION OF A SPECIALIST. (ERG, 2016)

Excerpt from ERG Guide 112 [Explosives* - Division 1.1, 1.2, 1.3 or 1.5]: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. (ERG, 2016)

An unstable explosive.

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.

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./|The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials. Nitrotriazolone is included on the dangerous goods list.|The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article. Nitrotriazolone is included on the dangerous goods list.

A skin and eye irritant.

IDENTIFICATION AND USE: Nitrotriazolone (NTO) is impact-insensitive explosive. HUMAN STUDIES: NTO elicited a mean tissue viability of 100.3 +/- 2.8% using the EPISKIN human epidermis skin constructs and therefore was predicted as non-irritant to the skin. Methemoglobin formation in isolated human erythrocytes for NTO was similar to that of nitrobenzene. There are reported cases of workers with throat irritations when breathing NTO dust. ANIMAL STUDIES: The rabbit eye test was considered negative; however, transient conjunctival and corneal irritation did result from the test substance application in several animals and one developed a chronic anterior uveitis. NTO was not a skin sensitizer in guinea pigs. The bovine leukemia virus-transformed lamb kidney fibroblasts FLK cell line cytotoxicity for NTO was similar to that of nitrobenzene. NTO induced testicular toxicity and oligospermia in repeated-dose oral toxicity tests in rats. To evaluate whether NTO produces additional reproductive and developmental effects, a modified extended one-generation reproductive toxicity test was conducted in rats. NTO did not markedly affect measures of fertility, including mating indices, gestation index, litter size, and sex ratio. Seminiferous tubule degeneration or atrophy was observed in P1 and F1 3600-mg/L NTO males. F1 males in the 3600 mg/L group exhibited reduced reproductive organ mass (testes, epididymides, and accessory sex organs). Nipple retention was increased in NTO exposed F1 males compared to controls. Attainment of puberty was delayed by 2.6 d in the 3600-mg/L NTO-exposed males relative to controls. NTO was negative in the Salmonella typhimurium/Escherichia coli Plate Incorporation Mutation Assay both with and without activation. NTO was not genotoxic in rat peripheral blood when tested in vivo. ECOTOXICITY STUDIES: Earthworms were exposed to concentrations of 1077 mg/L NTO solution in water for 48 hours; no mortality was observed.

LD50 Mice oral > 5 g/kg|LD50 Rat oral > 5g/kg

/AQUATIC SPECIES/ The 7 day IC50 values for test substance to Ceriodaphnia dubia /water flea/ was 57 mg/L. The NOEC and LOEC values for test substance to Ceriodaphnia dubia were 34 and 66 mg/L, respectively.|/AQUATIC SPECIES/ A preliminary bioconcentration factor of 0.25 L/kg was determined for the insensitive munitions compound 3-nitro-1,2,4-trizole-5-one (NTO) indicating negligible bioaccumulative potential. Because of the rapid elimination rate for explosives, tadpoles inhabiting contaminated areas are expected to experience harmful effects only if under constant exposure conditions given that body burdens can rapidly depurate preventing tissue concentrations from persisting at levels that may cause detrimental biological effects.|/AQUATIC SPECIES/ An initiative within the US military is targeting the replacement of traditional munitions constituents with insensitive munitions to reduce risk of accidental detonation. The purpose of the present study was to comparatively assess toxicity of the traditional munitions constituents 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) with the new insensitive munitions constituents 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO). The following exposure durations were performed with Rana pipiens (leopard frog) tadpoles: TNT and DNAN, 96 hr and 28 days; RDX, 10 days and 28 days; NTO, 28 days. The 96-hr 50% lethal concentration (LC50) values and 95% confidence intervals for TNT and DNAN were 4.4 mg/L (4.2 mg/L, 4.7 mg/L) and 24.3 mg/L (21.3 mg/L, 27.6 mg/L), respectively. No significant impacts on survival were observed in the 10-day exposure to RDX up to 25.3 mg/L. Effects on tadpole swimming distance were observed with a lowest-observed-effect concentration (LOEC) of 5.9 mg/L RDX. In the 28-day exposures, the LOECs for survival for TNT, DNAN, and NTO were 0.003 mg/L, 2.4 mg/L, and 5.0 mg/L, respectively. No significant mortality was observed in the RDX chronic 28-day exposure up to the highest treatment level tested of 28.0 mg/L. Neither tadpole developmental stage nor growth was significantly affected in any of the 28-day exposures. Rana pipiens were very sensitive to chronic TNT exposure, with an LOEC 3 orders of magnitude lower than those for insensitive munitions constituents DNAN and NTO.|/AQUATIC SPECIES/ ... The insensitive munition IMX-101 is a mixture of 2,4-dinitroanisole (DNAN), 3-nitro-1,2,4-triazol-5-one (NTO), and nitroguanidine (NQ). Environmental releases of munitions may be from production wastewaters or training; these munitions may be exposed to ultraviolet (UV) light. Therefore, it is useful to understand the relative toxicity of IMX-101 and its constituents both before and after photodegradation. The intent of the present study was to generate relative hazard information by exposing the standard ecotoxicological model Ceriodaphnia dubia to each insensitive munition constituent individually and to IMX-101 before and after the exposure solution was irradiated in a UV photoreactor. Without photodegradation, DNAN was more toxic (median lethal concentration [LC50]=43 mg/L) than the other 2 constituents and it contributed predominantly to the toxicity of IMX-101 (LC50= 206 mg/L) based on toxic units. Toxicity was observed only at high levels of NQ (LC50= 1174 mg/L) and pH-adjusted NTO (LC50= 799 mg/L). The toxicity of IMX-101 is lower than literature-reported TNT toxicity. Photodegradation efficiency was greater at lower insensitive munition concentrations. The observed degradation was greatest for NQ (42-99%), which in turn corresponded to the greatest relative increase in toxicity (100-1000-fold). Modest percent of degradation (4-18%) and increases in phototoxicity (2-100-fold) were observed for NTO and DNAN. Photodegraded NQ products were the predominant source of toxicity of photodegraded IMX-101. Future work involves research to enable analytical and computational confirmation of the specific degradation compounds inducing the observed photoenhanced toxicity.|/OTHER TERRESTRIAL SPECIES/ An earthworm contact test was carried out using NTO. Earthworms were exposed to concentrations of 1077 mg/L NTO solution in water for 48 hours, no mortality was observed. The NOEC was the maximum concentration tested, 1077 mg/L.

Nitrotriazolone's production and use as an explosive compound in insensitive munitions (IM), developed to replace traditional explosives TNT and RDX(1), may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of less than 1.0 determined in 11 different soils(2) indicate that nitrotriazolone is expected to have very high mobility in soil(SRC). Volatilization of nitrotriazolone from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 4.1X10-13 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Nitrotriazolone is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 3.1X10-8 mm Hg at 25 °C(SRC), determined from a fragment constant method(3). In kinetic experiments using 11 soils, nitrotriazolone had first-order transformation half-lives ranging from 2 to 72 days(2); faster transformation in untreated soil versus sterilized soil suggested that nitrotriazolone was being biodegraded(2). Microcosm studies in 7 soils found that nitrotriazolone was readily degraded under anaerobic conditions, but not degraded under aerobic conditions(4).|AQUATIC FATE: Based on a classification scheme(1), Koc values of less than 1.0 determined in 11 different soils(2), indicates that nitrotriazolone is not expected to adsorb to suspended solids and sediment(SRC). A pKa of 3.76(3) indicates nitrotriazolone will exist partially to almost entirely in the anion form at pH values of 5 to 9 and, therefore, volatilization from water surfaces is not expected to be an important fate process for the ionized species(SRC). Volatilization from water surfaces is also not expected for the non-ionized species(4) based upon an estimated Henry's Law constant of 4.1X10-13 atm-cu m/mole(SRC), developed using a fragment constant estimation method(5). According to a classification scheme(6), an estimated BCF of 3(SRC), from its log Kow of -1.699(3) and a regression-derived equation(5), suggests the potential for bioconcentration in aquatic organisms is low. Utilizing a closed-bottle test (OECD Guideline 306) with a seawater inoculum, nitrotriazolone was found to be not readily biodegradable with 3% degradation after 28 days of incubation(3). Soil tests found nitrotriazolone readily biodegradable under anaerobic conditions, but not under aerobic conditions(7). Nitrotriazolone was determined to be hydrolytically stable under acidic, neutral and basic conditions with a half-life of >1 year at 25 °C(3). In aqueous solution, nitrotriazolone was found to photodegrade at wavelengths within the range of solar irradiation with >90% degraded after 7 days(3).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), nitrotriazolone, which has an estimated vapor pressure of 3.1X10-8 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 nitrotriazolone 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 14 days(SRC), calculated from its rate constant of 1.1X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(2). Particulate-phase nitrotriazolone may be removed from the air by wet and dry deposition(SRC). Nitrotriazolone absorbs at wavelengths >290 nm(3) and is susceptible to direct photolysis by sunlight(SRC).

The rate constant for the vapor-phase reaction of nitrotriazolone with photochemically-produced hydroxyl radicals has been estimated as 1.1X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 14 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Nitrotriazolone was determined to be hydrolytically stable under acidic, neutral and basic conditions with a half-life of >1 year at 25 °C(2). In aqueous solution, nitrotriazolone was found to photodegrade at wavelengths within the range of solar irradiation via hydrolytic denitration and photo-rearrangement with >90% degraded after 7 days; ammonia, nitrite and nitrate were detected as final products(2).

An estimated BCF of 3 was calculated in fish for nitrotriazolone(SRC), using a log Kow of -1.699(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). A BCF of 0.25 was measured in Rana pipiens tadpoles(4).|... Using the Northern leopard frog, Rana pipiens, a preliminary bioconcentration factor of 0.25 L/kg was determined for the insensitive munitions compound 3-nitro-1,2,4-trizole-5-one (NTO) indicating negligible bioaccumulative potential. ...

A series of kinetic and equilibrium batch experiments using 11 soils found that nitrotriazolone experienced minimal adsorption with Koc values of less than 1 in all soils(1). According to a classification scheme(2), these Koc values suggest that nitrotriazolone is expected to have very high mobility in soil.

A pKa of 3.76(1) indicates nitrotriazolone will exist partially to almost entirely in the anion form at pH values of 5 to 9 and, therefore, volatilization from water surfaces is not expected to be an important fate process for the ionized species(SRC). The Henry's Law constant for non-ionized nitrotriazolone is estimated as 4.1X10-13 atm-cu m/mole(SRC) using a fragment constant estimation method(2). This Henry's Law constant indicates that nitrotriazolone is expected to be essentially nonvolatile from water surfaces(3). Nitrotriazolone's Henry's Law constant indicates that volatilization from moist soil surfaces is not expected to occur(SRC). Nitrotriazolone is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 3.1X10-8 mm Hg(SRC), determined from a fragment constant method(2).

According to the 2016 TSCA Inventory Update Reporting data, 1 reporting facility estimates the number of persons reasonably likely to be exposed during the manufacturing, processing, or use of nitrotriazolone in the United States may be as low as 100 workers and as high as 500 workers per plant; the data may be greatly underestimated due to confidential business information (CBI) or unknown values(1).|Occupational exposure to nitrotriazolone may occur through inhalation and dermal contact with this compound at workplaces where nitrotriazolone is produced or used(SRC). Potential worker exposures include particulates from the initial mixing process with dry components and nitrotriazolone vapors associated with the molten nitrotriazolone and the IMX-101 munition mixtures(1).

Based on in vivo toxicity studies, there is good evidence that the test substance is absorbed via the gastrointestinal tract and to a lesser extent via the skin. There is also evidence of systemic distribution to the liver in male and female rats and the testes. The liver may be a site of metabolism and the kidneys a possible route of excretion. In rat liver microsomes, the substance undergoes nitroreduction leading to the formation of ATO (5-amino-1,2,4-triazol-3-one), a primary amine. NTO also undergoes an oxidative denitrification, providing urazole and nitrite.|3-Nitro-1,2,4-triazol-5-one (NTO) is a component of insensitive munitions that are potential replacements for conventional explosives. Toxicokinetic data can aid in the interpretation of toxicity studies and interspecies extrapolation, but only limited data on the toxicokinetics and metabolism of NTO are available. To supplement these limited data, further in vivo studies of NTO in rats were conducted and blood concentrations were measured, tissue distribution of NTO was estimated using an in silico method, and physiologically based pharmacokinetic models of the disposition of NTO in rats and macaques were developed and extrapolated to humans. The model predictions can be used to extrapolate from designated points of departure identified from rat toxicology studies to provide a scientific basis for estimates of acceptable human exposure levels for NTO.

In the present study, we synthesized (14)C-labeled 5-nitro-1,2,4-triazol-3-one (NTO) and investigated its hepatic metabolism by dexamethasone-induced murine hepatic microsomes. Under the nitrogen atmosphere, 5-amino-1,2,4-triazol-3-one was the only detected metabolite of NTO. The microsomal nitroreductase activity was dependent on NADPH, totally inhibited by carbon monoxide and partially inhibited by oxygen. In aerobic conditions, beside a low amount of amine, the major metabolite formed is the 5-hydroxy-triazolone, urazole. This compound resulted from the oxidative denitrification of NTO, which produced equivalent amount of nitrite. This reaction, like the nitroreductase activity, was dependent on NADPH and totally inhibited by carbon monoxide. Both nitroreduction and oxidative denitrification were inhibited by imidazole-related inhibitors: miconazole and methimazole, and to a less extent by N-octylamine. The microsomal denitrification was induced by the treatment of rats with dexamethasone and phenobarbital. The microsomal reductase activity is present in untreated rat microsomes, and recovered with various inducers. The results of this study indicate the role played by cytochrome P-450 in the metabolism of NTO, supported by its transformation with reconstituted cytochrome P-450 systems.|In the present study, we have investigated the metabolism of the explosive 5-nitro-1,2,4-triazol-3-one (NTO) 1. (14)C5- and (14)C3-labeled NTO were synthesized to facilitate the elucidation of its bacterial and mammalian metabolism. The metabolites formed were characterised, and the degradative pathways compared. The Bacillus licheniformis strain was isolated from industrial waste containing high concentrations of the explosive (15 g/L). Microbial metabolism of NTO 1 proceeded through an oxygen-insensitive nitroreduction leading to the primary amine ATO (5-amino-1,2,4,-triazol-3-one) 2, followed by cleavage of the triazolone ring. The maximum microbial nitroreduction occurred at pH 6 in the presence of sucrose, while the ring, cleavage occurred at pH 8. A permanent control and adjustment of the pH was required to achieve the complete degradation of NTO by B. licheniformis. The triazolone ring resulted from the hydrolysis of the 'pseudo guanido' group (R-NH-C(NH2)=N-R').|Based on in vivo toxicity studies, there is good evidence that the test substance is absorbed via the gastrointestinal tract and to a lesser extent via the skin. There is also evidence of systemic distribution to the liver in male and female rats and the testes. The liver may be a site of metabolism and the kidneys a possible route of excretion. In rat liver microsomes, the substance undergoes nitroreduction leading to the formation of ATO (5-amino-1,2,4-triazol-3-one), a primary amine. NTO also undergoes an oxidative denitrification, providing urazole and nitrite.

short elimination half-lives (1.2 hr or less) /Rana pipiens tadpoles/

Excerpt from ERG Guide 112 [Explosives* - Division 1.1, 1.2, 1.3 or 1.5]: Fire may produce irritating, corrosive and/or toxic gases. (ERG, 2016)

Excerpt from ERG Guide 112 [Explosives* - Division 1.1, 1.2, 1.3 or 1.5]: Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. (ERG, 2016)

/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 if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the 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. /Poisons A and B/|/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 needed. 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 ... . Anticipate 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 patient can swallow, has a strong gag reflex, and does not drool ... . /Poisons A and B/|/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 as necessary ... . Start IV administration of D5W TKO /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. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/

/CASE REPORTS/ ...reported cases of workers with throat irritations when breathing NTO dust.|/ALTERNATIVE and IN VITRO TESTS/ The toxicity of conventional nitroaromatic explosives like 2,4,6-trinitrotoluene (TNT) is caused by their enzymatic free radical formation with the subsequent oxidative stress, the formation of alkylating nitroso and/or hydroxylamino metabolites, and oxyhemoglobin oxidation into methemoglobin. In order to get an insight into the mechanisms of toxicity of the novel explosives NTO (5-nitro-1,2,4-triazol-3-one) and ANTA (5-nitro-1,2,4-triazol-3-amine), we examined their reactions with the single-electron transferring flavoenzymes NADPH: cytochrome P-450 reductase and ferredoxin:NADP+ reductase, two-electron transferring flavoenzymes mammalian NAD(P)H:quinone oxidoreductase (DT-diaphorase), and Enterobacter cloacae NAD(P)H:nitroreductase, and their reactions with oxyhemoglobin. The reactivity of NTO and ANTA in the above reactions was markedly lower than that of TNT. The toxicity of NTO and ANTA in bovine leukemia virus-transformed lamb kidney fibroblasts (line FLK) was partly prevented by desferrioxamine and the antioxidant N,N'-diphenyl-p-phenylene diamine, and potentiated by 1,3-bis-(2-chloroethyl)-1-nitrosourea. This points to the involvement of oxidative stress in their cytotoxicity, presumably to the redox cycling of free radicals. The FLK cell line cytotoxicity and the methemoglobin formation in isolated human erythrocytes of NTO and ANTA were also markedly lower than those of TNT, and similar to those of nitrobenzene. Taken together, our data demonstrate that the low toxicity of nitrotriazole explosives may be attributed to their low electron-accepting properties.|/ALTERNATIVE and IN VITRO TESTS/ The test substance, NTO, elicited a mean tissue viability of 100.3 +/- 2.8% using the EPISKIN human epidermis skin constructs and therefore was predicted as non-irritant to the skin.

3-nitro-1,2,4-triazole-5-one

NTO exists in two polymorphic forms, that is, alpha-form and beta-form. It has been established that alpha-NTO is the stable and dominating form whereas beta-NTO is only found in the product on recrystallization of NTO from a methanol or ethanol/methylene chloride mixture.

Explosives manufacturing|3H-1,2,4-Triazol-3-one, 1,2-dihydro-5-nitro-: ACTIVE|PMN - indicates a commenced PMN (Pre-Manufacture Notices) substance.|NTO was developed as a potential replacement for RDX and other energetics in military munitions. It is a component of IMX-101, an insensitive munition designed to prevent unplanned explosions. IMX-101 and other insensitive formulations exhibit a reduced potential for detonation resulting from impact and fires in military combat vehicles and aircraft.|NTO is being developed in many areas. These include (1) a substitute for ammonium perchlorate or ammonium nitrate in solid rocket propellants, since it does not liberate undesirable products such as HCl and has quite a high burn rate compared to ammonium perchlorate and ammonium nitrate, (2) used as a burning rate modifier for composite propellants, (3) replacing RDX and HMX in composite solid propellants, and (4) improving the performance of gun propellants.|Differential scanning calorimetry (DSC) profile indicated that Li and K salts of NTO and TABA undergo exothermic decomposition in the temperature range of 257-360 degrees C suggesting their energetic nature. The thermo gravimetric (TG) weight loss pattern revealed loss of water for Li/K salts of NTO and TABA in the temperature range of 115-155 degrees C. Sensitivity results revealed that the compounds are insensitive to impact and friction (impact sensitivity--height of 50% explosion>170 cm and friction insensitivity up to 36 kg) stimuli despite even the parent molecule of NTO salts (NTO) being HEM in the hazard category of 1.1. The FTIR spectra of the gaseous products evolved during TGA of NTO and TABA salts indicated the release of NO2. The formation of products such as LiNCO and KNCO was also observed in case of NTO salts, whereas that of CO2 and NH containing products was indicated in case of TABA salts during this study. In order to assess the performance as energetic ballistic modifiers (EBMs), NTO and TABA salts were incorporated in the ammonium perchlorate-hydroxyl terminated polybutadiene (AP-HTPB) composite propellants. The potassium salts enhanced the burning rate of the propellant. The best catalytic effect was obtained with K-TABA salt, which increased the burning rate to the extent of approximately 81% as well as brought down the n-value to 0.15 (pressure 2-9 MPa). /Lithium and potassium salts/

As there are no molecular spectroscopic determination methods for the most widely used insensitive energetic materials, 2,2',4,4',6,6'-hexanitrostilbene (HNS) and 3-nitro-1,2,4-triazole-5-one (NTO), in the presence of sensitive nitro-explosives, two novel spectrophotometric methods were developed. For HNS and TNT mixtures, both analytes react with dicyclohexylamine (DCHA) forming different colored charge-transfer complexes, which can be resolved by derivative spectroscopy. The spectrophotometric method for NTO measures the 416-nm absorbance of its yellow-colored Na(+)NTO(-) salt formed with NaOH. TNT, if present, is pre-extracted into IBMK as its Meisenheimer anion forming an ion-pair with the cationic surfactant cetyl pyridinium (CP(+)) in alkaline medium, whereas the unextracted NTO is determined in the aqueous phase. The molar absorptivity (e, L/mol /per/ cm) and limit of quantification (LOQ, mg/L) are as follows: for HNS, e=2.75 x 10(4) and LOQ=0.48 (in admixture with TNT); for NTO, e=6.83 x 10(3) and LOQ=0.73. These methods were not affected from nitramines and nitrate esters in synthetic mixtures or composite explosives. The developed methods were statistically validated against HPLC, and the existing chromatographic method was modified so as to enable NTO determination in the presence of TNT. These simple, low-cost, and versatile methods can be used in criminology, remediation/monitoring of contaminated sites, and kinetic stability modeling of munitions containing desensitized energetic materials.|A graphene-based nanosensor was fabricated to selectively detect nitrotriazolone (NTO) molecules with a molecularly imprinted film via simple electrical measurements. Molecularly imprinted polymer comprising chitosan was used as sensitive layer. Gold electrodes for electrical measurements were lithographically fabricated on Si/SiO2 substrate, followed by monolayer graphene transfer and polymeric film coating. Monolayer graphene and molecularly imprinted polymer were characterized by ATR-FTIR, UV-Vis, SEM and Raman spectroscopy. Transfer-length measurements (TLM) indicate that the sensor selectively and linearly responds against aqueous NTO solutions within a wide range of concentration of 0.01-0.1 mg/mL that covers the lowest toxic level of NTO determined by USEPA. This nanosensor with embedded electrodes is re-usable and suitable for field applications, offering real-time electrical measurements unlike current techniques where complex analytics are required.