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Bromoethane
Bromoethane
Bromoethane
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Bromoethane
Skeletal formula of bromoethane
Skeletal formula of bromoethane
Skeletal formula of bromoethane with all explicit hydrogens added
Skeletal formula of bromoethane with all explicit hydrogens added
Ball and stick model of bromoethane
Ball and stick model of bromoethane
Spacefill model of bromoethane
Spacefill model of bromoethane
Names
Preferred IUPAC name
Bromoethane[2]
Other names
Ethyl bromide[1]
Monobromoethane[1]
Identifiers
3D model (JSmol)
1209224
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.000.751 Edit this at Wikidata
EC Number
  • 200-825-8
KEGG
MeSH bromoethane
RTECS number
  • KH6475000
UNII
UN number 1891
  • InChI=1S/C2H5Br/c1-2-3/h2H2,1H3 checkY
    Key: RDHPKYGYEGBMSE-UHFFFAOYSA-N checkY
  • CCBr
Properties
C2H5Br
Molar mass 108.966 g·mol−1
Appearance Colorless liquid
Odor ether-like
Density 1.46 g mL−1
Melting point −120 to −116 °C; −184 to −177 °F; 153 to 157 K
Boiling point 38.0 to 38.8 °C; 100.3 to 101.8 °F; 311.1 to 311.9 K
1.067 g/100 mL (0 °C)
0.914 g/100 mL (20 °C)
0.896 g/100 mL (30 °C)
Solubility miscible with ethanol, ether, chloroform, organic solvents
log P 1.809
Vapor pressure 51.97 kPa (at 20 °C)
1.3 μmol Pa−1 kg−1
−54.70·10−6 cm3/mol
1.4225
Viscosity 402 Pa.s (at 20 °C)
Thermochemistry
105.8 J K−1 mol−1
−97.6–93.4 kJ mol−1
Hazards
GHS labelling:
GHS02: Flammable GHS06: Toxic GHS08: Health hazard
Danger
H225, H302, H332, H351
P210, P281
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
3
1
0
Flash point −23 °C (−9 °F; 250 K)
511 °C (952 °F; 784 K)
Explosive limits 6.75–11.25%
Lethal dose or concentration (LD, LC):
1.35 g kg−1 (oral, rat)
26,980 ppm (rat, 1 hr)
16,230 ppm (mouse, 1 hr)
4681 ppm (rat)
2723 ppm (mouse)[3]
3500 ppm (mouse)
24,000 ppm (guinea pig, 30 min)
7000 ppm (guinea pig, >4.5 hr)[3]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 200 ppm (890 mg/m3)[1]
REL (Recommended)
 None established[1]
IDLH (Immediate danger)
 2000 ppm[1]
Related compounds
Related alkanes
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Bromoethane, also known as ethyl bromide, is a chemical compound of the haloalkanes group. It is abbreviated by chemists as EtBr (which is also used as an abbreviation for ethidium bromide). This volatile compound has an ether-like odor.

Preparation

[edit]

The preparation of EtBr stands as a model for the synthesis of bromoalkanes in general. It is usually prepared by the addition of hydrogen bromide to ethene:

H2C=CH2 + HBr → H3C-CH2Br

Bromoethane is inexpensive and would rarely be prepared in the laboratory. A laboratory synthesis includes reacting ethanol with a mixture of hydrobromic and sulfuric acids. An alternate route involves refluxing ethanol with phosphorus and bromine; phosphorus tribromide is generated in situ.[4]

Uses

[edit]

In organic synthesis, EtBr is the synthetic equivalent of the ethyl carbocation (Et+) synthon.[5] In reality, such a cation is not actually formed. For example, carboxylates salts are converted to ethyl esters,[6] carbanions to ethylated derivatives, thiourea into ethylisothiouronium salts,[7] and amines into ethylamines.[8]

Safety

[edit]

Short chain monohalocarbons in general are potentially dangerous alkylating agents. Bromides are better alkylating agents than chlorides, thus exposure to them should be minimized.

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Bromoethane

View on Grokipedia
from Grokipedia
Bromoethane, also known as ethyl bromide, is a simple organobromine compound with the C₂H₅Br and a molecular weight of 108.97 g/mol. It is a volatile, colorless to pale yellow liquid with an ether-like odor, characterized by a low of 38.2 °C, a of -118.4 °C, and a of 1.46 g/cm³ at 20 °C. Primarily employed as an alkylating and ethylating agent in , bromoethane serves as a key intermediate for producing pharmaceuticals, s, and other chemicals, though its historical applications included use as a , extraction , additive, and limited . Bromoethane is industrially produced by refluxing with , a process that leverages the substitution of the hydroxyl group in ethanol with . It also occurs naturally in trace amounts, emitted by macroalgae and volcanic activity, and has been detected in ocean air. Chemically, it acts as a reactive , undergoing in with a of approximately 30–40 days and reacting with atmospheric hydroxyl radicals over about 45 days. Due to its flammability ( of -20 °C) and , bromoethane poses significant risks, including irritation to the skin, eyes, and , central nervous system depression, and potential liver and damage; it is classified as a suspected with an immediately dangerous to life or health concentration of 2,000 ppm.

Chemical Identity and Properties

Nomenclature and Molecular Formula

Bromoethane, also known as ethyl bromide, is the for this , with the abbreviation EtBr commonly used in chemical notation. The compound represents a simple alkyl bromide where substitutes one in . Its molecular formula is C₂H₅Br, and the is CH₃CH₂Br, indicating a two-carbon chain with the bromine atom attached to the terminal carbon. The of bromoethane is 108.966 g/mol. Bromoethane was first synthesized in 1827 by the French chemist Georges-Simon Serullas through the reaction of with and . This preparation occurred shortly after the discovery of elemental in 1826 by Antoine Jérôme Balard. In terms of molecular structure, the carbon atom bonded to the bromine exhibits sp³ hybridization, resulting in a tetrahedral with bond angles near 109.5°. The C-Br is approximately 1.94 Å.

Physical Properties

Bromoethane appears as a colorless, volatile liquid at room temperature, exhibiting an ether-like odor. Its boiling point ranges from 38.0 to 38.8 °C at 1 atm, reflecting its low boiling volatility suitable for laboratory handling under ambient conditions. The melting point is -119 °C, indicating it remains liquid over a wide temperature range above this threshold. The density of bromoethane is 1.46 g/mL at 20 °C, which is higher than that of water, contributing to its behavior in mixed solvent systems. It shows limited solubility in water, at 0.914 g/100 mL at 20 °C, but is fully miscible with common organic solvents such as ethanol, ether, and chloroform, facilitating its use in extraction processes. Vapor pressure is approximately 442 mmHg at 20 °C, underscoring its tendency to evaporate readily and produce vapors heavier than air. The refractive index is 1.423 at 20 °C, a value typical for halogenated hydrocarbons of similar structure.
PropertyValueConditionsSource
AppearanceColorless volatile liquid, ether-like odorRoom temperaturePubChem
Boiling point38.0–38.8 °C1 atmPubChem
Melting point-119 °C-PubChem
Density1.46 g/mL20 °CPubChem
Solubility in water0.914 g/100 mL20 °CPubChem
MiscibilityWith ethanol, ether, chloroform-PubChem
Vapor pressure~442 mmHg20 °CFisher Scientific SDS
Refractive index1.42320 °CPubChem

Thermodynamic Properties

Bromoethane exhibits thermodynamic properties that reflect its molecular structure and intermolecular forces, particularly the polar C-Br bond, which contributes to its relatively high compared to nonpolar hydrocarbons of similar size. These properties are crucial for predicting phase behavior, stability, and energy changes in processes involving the compound. Key energetic data include the for the liquid phase at 298 , which is -95.5 ± 2.1 kJ/mol, derived from measurements. This value indicates moderate exothermicity in forming the liquid from elements in their standard states (carbon as , hydrogen gas, and liquid). For the gas phase, the is -61.9 ± 1.0 kJ/mol, less negative due to the endothermic process. The standard of formation for gaseous bromoethane at 298 is -23.9 kJ/mol, signifying that the formation reaction is spontaneous under standard conditions despite the decrease associated with bond formation. The at constant pressure for the phase at 25 °C is 105.8 J/mol·, allowing for efficient absorption in thermal processes near . This value, obtained from calorimetric studies, is higher than that of nonpolar analogs, attributable to dipole-dipole interactions enhancing vibrational and rotational contributions to . Phase transition energetics are characterized by the , which is 27.0 ± 0.1 kJ/mol at the normal of approximately 311 K, reflecting the required to overcome intermolecular forces during . Beyond the critical point, defined by a critical of 231 °C and critical of 6.15 MPa, distinct and vapor phases cease to exist, marking the end of the vapor- equilibrium curve. The molecule's dipole moment of 2.04 D further underscores its polarity, arising from the difference between carbon and (C-Br bond polarity ≈ 0.4–0.5 on the Pauling scale), which influences properties and in polar solvents.
PropertyValuePhase/ConditionsSource
Standard enthalpy of formation (Δ_f H°)-95.5 ± 2.1 kJ/mol, 298 NIST [Ashcroft et al., 1965]
Standard Gibbs free energy of formation (Δ_f G°)-23.9 kJ/molGas, 298 Engineering Toolbox
Heat capacity (C_p)105.8 J/mol·K, 25 °CNIST [Shehatta, 1993]
Enthalpy of vaporization (Δ_vap H)27.0 ± 0.1 kJ/molAt (311 )NIST [Svoboda et al., 1977]
Critical temperature (T_c)231 °C-Stenutz
Critical (P_c)6.15 MPa-Stenutz
Dipole moment (μ)2.04 DGas/liquidStenutz

Synthesis

Laboratory Synthesis

Bromoethane is commonly prepared in laboratory settings through the of with a bromide source, yielding the alkyl via an SN2 mechanism under mild conditions suitable for small-scale synthesis. One standard method involves the reaction of with , which can be used directly or generated . The balanced equation is: CH3CH2OH+HBr→CH3CH2Br+H2O\text{CH}_3\text{CH}_2\text{OH} + \text{HBr} \rightarrow \text{CH}_3\text{CH}_2\text{Br} + \text{H}_2\text{O} This reaction is often catalyzed by concentrated to facilitate of the alcohol, enhancing the leaving group departure, or alternatively employs (PBr3) as the brominating agent for cleaner conversion without excess acid. In practice, is prepared by adding concentrated to solid in the presence of ; the sulfuric acid protonates the bromide to release HBr gas, which then reacts with the alcohol upon gentle heating and . The equation for the in situ generation and reaction is: CH3CH2OH+KBr+H2SO4→CH3CH2Br+KHSO4+H2O\text{CH}_3\text{CH}_2\text{OH} + \text{KBr} + \text{H}_2\text{SO}_4 \rightarrow \text{CH}_3\text{CH}_2\text{Br} + \text{KHSO}_4 + \text{H}_2\text{O} The mixture is typically warmed under reflux before distillation to ensure complete reaction, with the low-boiling bromoethane (b.p. 38°C) collected in a cooled receiver. An alternative approach utilizes red phosphorus and to form , which then brominates the alcohol. The overall reaction is: 3CH3CH2OH+P+3Br2→3CH3CH2Br+H3PO33 \text{CH}_3\text{CH}_2\text{OH} + \text{P} + 3 \text{Br}_2 \rightarrow 3 \text{CH}_3\text{CH}_2\text{Br} + \text{H}_3\text{PO}_3 Here, red phosphorus reacts with to generate PBr3, which substitutes the hydroxyl group; the mixture is heated under to drive the reaction, followed by of the product. This method avoids strong acids and is preferred for sensitive substrates, though it requires careful handling of elemental . Regardless of the synthesis route, the crude bromoethane contains impurities such as unreacted , , residues, and minor elimination products. Purification typically involves sequential washing steps: first with to remove water-soluble byproducts, then with aqueous to neutralize acids, followed by drying over anhydrous . The purified liquid is then isolated by under reduced pressure to minimize volatilization losses and , collecting the fraction boiling at approximately 38°C at (or lower under ).

Industrial Production

Bromoethane is primarily produced on an industrial scale through two main processes: the hydrobromination of and the reaction of with . The hydrobromination method involves the direct addition of (HBr) to gas, following the reaction \ceCH2=CH2+HBr−>CH3CH2Br\ce{CH2=CH2 + HBr -> CH3CH2Br}. This process is highly efficient due to the availability of as a feedstock and operates under controlled pressure and temperature conditions in continuous-flow reactors, making it suitable for large-scale production. The reaction proceeds via an mechanism, yielding high-purity product with minimal byproducts when optimized. The alternative industrial route utilizes and concentrated aqueous HBr, derived from bromide salts and , in the \ceCH3CH2OH+HBr−>CH3CH2Br+H2O\ce{CH3CH2OH + HBr -> CH3CH2Br + H2O}. This method is conducted in setups where the bromoethane is continuously removed as it forms, typically at temperatures of 45–50°C, followed by neutralization and . It leverages inexpensive bio-derived or fermented , enhancing economic viability in regions with abundant alcohol supplies, though it requires careful control to avoid side reactions forming . Raw material consumption is approximately 557 kg of 95% and 1610 kg of 48% HBr per metric ton of product. Both processes achieve yields of 90–96% and produce bromoethane with 98–99% purity after and washing steps, such as treatment with and to remove impurities like unreacted alcohol or acids. Economic considerations favor these methods for their scalability and low-cost catalysts, with global production centered in , the , and by a handful of specialized chemical firms. Byproducts are minimized through precise temperature and ratio control, ensuring high efficiency and compliance with environmental standards. Historically, bromoethane production expanded in the early to meet demand as a and , but contemporary manufacturing focuses on its role as a versatile intermediate in and pharmaceuticals, reflecting shifts in regulatory and market priorities.

Chemical Reactions

Nucleophilic Substitution

Bromoethane, as a primary alkyl , undergoes reactions predominantly via the bimolecular SN2 mechanism, in which a attacks the carbon atom bonded to the from the backside, leading to a concerted displacement of the bromide ion. This process results in inversion of configuration at the carbon center, though bromoethane is achiral and thus does not exhibit observable in the product. The reaction rate follows second-order kinetics, expressed as rate = kk [CH3_3CH2_2Br][Nu−^-], depending on the concentrations of both the substrate and the . The preference for the SN2 pathway in bromoethane arises from steric factors associated with its primary carbon, which minimizes hindrance to the nucleophile's approach compared to secondary or tertiary halides, thereby disfavoring the unimolecular SN1 mechanism that involves a intermediate. serves as an effective due to its weak basicity and , facilitating clean departure during substitution. Additionally, play a key role; polar aprotic solvents, such as (DMSO) or acetone, accelerate SN2 reactions by solvating cations but leaving the anion relatively unsolvated and thus more reactive, in contrast to polar protic solvents that stabilize the nucleophile through hydrogen bonding. Representative examples of SN2 reactions with bromoethane include its hydrolysis with hydroxide ion to form ethanol: CH3_3CH2_2Br + OH−^- →\rightarrow CH3_3CH2_2OH + Br−^-. Reaction with ammonia yields ethylamine: CH3_3CH2_2Br + NH3_3 →\rightarrow CH3_3CH2_2NH2_2 + HBr. Similarly, treatment with cyanide ion produces propanenitrile: CH3_3CH2_2Br + CN−^- →\rightarrow CH3_3CH2_2CN + Br−^-, a common step in nitrile synthesis for extending carbon chains. These reactions highlight bromoethane's utility in SN2 processes under mild conditions.

Elimination Reactions

Bromoethane undergoes elimination reactions primarily through the E2 mechanism, a concerted bimolecular process in which a strong base abstracts a β-hydrogen while the departs simultaneously, forming a carbon-carbon . This reaction requires anti-periplanar geometry between the β-hydrogen and the leaving group for optimal orbital overlap in the . The rate law follows second-order kinetics: rate = k [CH₃CH₂Br][base], reflecting the involvement of both the substrate and the base in the rate-determining step. A representative example is the dehydrohalogenation of bromoethane with hydroxide ion in alcoholic solution, yielding as the major product: CH3CH2Br+OH−→CH2=CH2+HBr+H2O\mathrm{CH_3CH_2Br + OH^- \rightarrow CH_2=CH_2 + HBr + H_2O} This reaction proceeds efficiently under heating, with the alcoholic medium providing the strong, conditions necessary for elimination. In accordance with Zaitsev's rule, the elimination favors the more stable product; however, for bromoethane, only one type of β-hydrogen is available on the , leading exclusively to the terminal , . These reactions are typically conducted at elevated temperatures in non-aqueous solvents, such as ethanol, to promote elimination over the competing nucleophilic substitution pathway.

Reactions with Metals and Oxidants

Bromoethane undergoes reductive coupling when treated with alkali metals such as sodium, forming butane via the Wurtz reaction. The balanced equation for this process is: 2\ceCH3CH2Br+2\ceNa→\ce(CH3CH2)2+2\ceNaBr2 \ce{CH3CH2Br} + 2 \ce{Na} \rightarrow \ce{(CH3CH2)2} + 2 \ce{NaBr} This reaction is highly exothermic and requires careful control to manage the heat generated, often conducted in an inert solvent like to facilitate the coupling. In the presence of magnesium metal, bromoethane forms the ethylmagnesium bromide, a key organometallic compound used in synthetic . The reaction occurs in anhydrous as the solvent: \ceCH3CH2Br+Mg−>CH3CH2MgBr\ce{CH3CH2Br + Mg -> CH3CH2MgBr} The stabilizes the highly reactive Grignard species, and the reaction initiates with the of magnesium to the carbon-bromine bond, typically requiring dry conditions to prevent side reactions with . Bromoethane can form explosive mixtures with powdered aluminum or magnesium, particularly under conditions favoring rapid organometallic formation or ignition. These interactions may lead to violent s, emphasizing the need for inert atmospheres during handling with such metals. Beyond typical elimination pathways, bromoethane can engage in violent reactions with strong bases, potentially leading to rapid or explosive gas evolution under forcing conditions.

Applications

In Organic Synthesis

Bromoethane functions as a key ethylating agent in , enabling the formation of ethyl esters from salts through reactions. In this process, the anion acts as a , displacing the bromide to yield the corresponding . A representative example is the reaction of with bromoethane, producing ethyl benzoate and :
\ceRCOO−Na++CH3CH2Br−>RCOOCH2CH3+NaBr\ce{RCOO^- Na^+ + CH3CH2Br -> RCOOCH2CH3 + NaBr}
This approach is valued in laboratory esterifications for its straightforward conditions and compatibility with a range of derivatives. In the of , bromoethane facilitates the conversion of primary amines to secondary amines, and further to tertiary amines or salts, by sequential addition of ethyl groups. The initial step involves the nitrogen attacking the electrophilic carbon of bromoethane, resulting in the formation of an ethylated and . For instance, a primary amine such as reacts as follows:
\ceRNH2+CH3CH2Br−>RNHCH2CH3+HBr\ce{RNH2 + CH3CH2Br -> RNHCH2CH3 + HBr}
This method is particularly useful for preparing amine-based intermediates, with reaction outcomes influenced by and conditions to control the degree of alkylation. Bromoethane plays a significant role in pharmaceutical synthesis by introducing ethyl groups into molecular frameworks, aiding the development of precursors with enhanced or bioactivity. It is also employed in the production of agrochemicals, such as certain insecticides and herbicides, and in dye manufacturing, where ethyl substitution modifies properties for desired color and stability. These applications underscore its utility in constructing complex carbon chains for high-value compounds. As a primary alkyl bromide, bromoethane exhibits high selectivity for SN2 pathways, benefiting from minimal steric hindrance at the reaction center and 's favorable ability, which promotes clean substitutions over competing elimination reactions. Yields are often optimized in polar aprotic solvents like , achieving efficiencies above 80% in model alkylations.

Industrial and Other Uses

Bromoethane serves primarily as a chemical intermediate in the production of pharmaceuticals, agrochemicals, and other fine chemicals, with global annual production estimated in the thousands of metric tons as of 2024, supported by facilities in major chemical manufacturing regions such as the , , and . One reported production capacity for a single facility reaches 3,000 tons annually, indicating a modest but steady industrial scale focused on downstream applications rather than high-volume commodities. In , bromoethane functions as an extraction solvent for isolating organic compounds, leveraging its solubility properties in nonpolar systems to separate target molecules from aqueous or complex mixtures. Historically, it was employed as a in early mechanical cooling systems due to its low and thermodynamic suitability, though its use has been largely phased out since the late due to health and safety concerns. Bromoethane saw limited application as an antiknock additive in formulations during the mid-20th century, where it acted as a component in mixtures to enhance performance and prevent , particularly in conjunction with lead-based additives. In research contexts, it is utilized as a model alkylating agent to investigate biochemical pathways, such as DNA and protein modification, providing insights into and cellular repair mechanisms in toxicological studies.

Safety and Environmental Impact

Health Hazards and Toxicity

Bromoethane is an alkylating agent that can cause genotoxic effects, including DNA damage , as demonstrated in bacterial and assays. It has been classified by the International Agency for Research on Cancer (IARC) as Group 3, not classifiable as to its carcinogenicity to humans, based on limited evidence in experimental animals, such as dose-related uterine tumors in female B6C3F1 mice exposed via . However, the National Program (NTP) reported clear evidence of carcinogenicity in female mice, leading to its listing under 65 as known to the state to cause cancer. Acute exposure to bromoethane primarily occurs via or contact, causing to the eyes, , and , with symptoms including redness, pain, and inflammatory lesions in the nasal passages and lungs at concentrations as low as 450 mg/m³ in rats. can lead to , manifesting as , , , drowsiness, and loss of coordination at higher levels, while oral exposure in rats has an LD50 of 1,350 mg/kg, indicating moderate . Occupational exposure limits include an OSHA (PEL) of 200 ppm (890 mg/m³) as an 8-hour time-weighted average and a NIOSH Immediately Dangerous to Life or Health (IDLH) value of 2,000 ppm, reflecting risks of and cardiac arrhythmias at elevated concentrations. Additionally, bromoethane's of -23 °C results in highly flammable vapors that pose an risk, exacerbating hazards during fires or spills. Chronic exposure to bromoethane is associated with neurological damage due to its (log Kow = 1.61), enabling it to cross the blood-brain barrier and accumulate in neural tissues, potentially leading to , tremors, and long-term as observed in high-dose animal studies. Repeated at levels above 450 mg/m³ has shown hematological and hepatic effects in rodents, including and liver congestion. Potential includes in male rats at 7,200 mg/m³ and reduced corpora lutea in female mice at 1,600 ppm, though no formal multigenerational studies confirm human relevance, and effects occur alongside severe maternal toxicity. Overall, chronic risks emphasize the need for strict exposure controls to prevent cumulative neurotoxic and oncogenic outcomes.

Handling and Storage Precautions

When handling bromoethane, appropriate (PPE) must be worn, including chemical-resistant gloves such as Viton (with a minimum breakthrough time of 60 minutes and thickness of 0.7 mm), safety goggles or face protection compliant with EN 166 or OSHA standards, flame-retardant antistatic clothing, and respiratory protection with an AX-type filter when vapors or aerosols are present. Operations should be conducted in a well-ventilated or area with explosion-proof equipment to prevent , contact, and ignition sources, using non-sparking tools and grounding all equipment to avoid static discharge. For storage, bromoethane should be kept in tightly closed containers in a cool (15–25°C), dry, well-ventilated area designated for flammables, away from , sparks, open flames, strong oxidizers, bases, and metals to prevent reactions or hazards. Suitable containers include for use or mild drums for larger quantities, with light-sensitive storage under refrigeration if pressure buildup is a concern. In case of fire, use dry chemical, , foam, or spray as extinguishing media, while avoiding direct streams on the material to prevent splashing; firefighters should wear and full protective gear due to the release of toxic gas. For spills, evacuate the area, ensure ventilation, remove ignition sources, and contain the liquid with inert absorbents like or before transferring to sealed containers for disposal; clean residues with non-sparking tools in a well-ventilated space. Bromoethane is classified as a hazardous for transport under 1891 (Ethyl bromide), with a primary hazard class of 3 () and subsidiary class 6.1 (toxic), requiring packing group II and proper labeling, placarding, and documentation per DOT, IMDG, and IATA regulations.

Environmental Effects

Bromoethane exhibits high volatility in environmental compartments, partitioning preferentially into the atmosphere due to its constant of 0.76 kPa·m³/mol, which facilitates rapid evaporation from and surfaces. Volatilization half-lives are estimated at 3.2 hours in flowing models and 38.2 hours in pond models, indicating limited persistence in aqueous environments beyond initial release. It has been detected in landfill at concentrations up to 170 mg/L, highlighting its potential for leaching through under anaerobic conditions typical of sites. In , bromoethane undergoes slow , with a of 21–30 days at 25 °C and neutral , further contributing to its moderate persistence before degradation. Atmospheric degradation occurs primarily via reaction with hydroxyl radicals, yielding a of approximately 45 days. Bioaccumulation potential for bromoethane is low, as evidenced by its (log Kow = 1.61), which predicts minimal uptake and retention in aquatic organisms (estimated bioconcentration factor of 5). This low limits its magnification through food chains, though short-term exposure in contaminated waters could still pose risks to sensitive species. Bromoethane is not classified as hazardous to the aquatic environment under EU CLP regulations. Predicted to yields an LC50 of approximately 415 mg/L (ECOSAR), indicating low to moderate hazard levels that necessitate avoidance of releases into surface waters or drains to prevent localized ecological impacts. Although brominated compounds like release bromine atoms that can catalytically destroy stratospheric , its short atmospheric lifetime restricts significant contribution to , and it is not regulated as an ozone-depleting substance under the . As a (VOC), bromoethane is subject to monitoring and emission controls in air quality regulations to mitigate broader atmospheric pollution.

References

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  27. https://www.chemguide.co.uk/mechanisms/nucsub/amines.html
  28. https://www.ibchem.com/IB25/r3.42.php
  29. https://www.youtube.com/watch?v=EqfM1eDaJxk
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  38. https://www.researchandmarkets.com/report/bromoethane-market
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  41. https://oehha.ca.gov/proposition-65/chemicals/bromoethane
  42. https://pubchem.ncbi.nlm.nih.gov/compound/Bromoethane#section=Toxicity
  43. https://www.cdc.gov/niosh/npg/npgd0265.html
  44. https://www.fishersci.com/store/msds?partNumber=AC154215000
  45. https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/bromoethane
  46. https://pubchem.ncbi.nlm.nih.gov/compound/Bromoethane#section=Chemical-and-Physical-Properties
  47. https://www.sigmaaldrich.com/US/en/sds/sial/239607
  48. https://www.fishersci.com/store/msds?partNumber=AC154215000&productDescription=BROMOETHANE%2B98%2525%2B500ML&vendorId=VN00032119&countryCode=US&language=en
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  50. https://canadachemicals.oecd.org/ChemicalDetails.aspx?ChemicalID=A563FB73-B3CF-4F66-9B60-FF3BB3B21D0D
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