Hexyl acetate

This chemical does not meet GHS hazard criteria for 0.4% (8 of 1939) of reports.

H226 (98%): Flammable liquid and vapor [Warning Flammable liquids]

H411 (85.5%): Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P210, P233, P240, P241, P242, P243, P273, P280, P303+P361+P353, P370+P378, P391, P403+P235, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 1939 reports by companies from 12 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Reported as not meeting GHS hazard criteria per 8 of 1939 reports by companies.

There are 11 notifications provided by 1931 of 1939 reports by companies with hazard statement code(s).

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

H226: Flammable liquid and vapor [Warning Flammable liquids]

H315: Causes skin irritation [Warning Skin corrosion/irritation]

H320: Causes eye irritation [Warning Serious eye damage/eye irritation]

H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

P210, P233, P240, P241, P242, P243, P261, P264, P264+P265, P271, P280, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Excerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:

Refer to the "General First Aid" section. Specific First Aid: Wash skin with soap and water. In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin. (ERG, 2024)

Excerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:

CAUTION: The majority of these products have a very low flash point. Use of water spray when fighting fire may be inefficient. CAUTION: For mixtures containing alcohol or polar solvent, alcohol-resistant foam may be more effective.

SMALL FIRE: Dry chemical, CO2, water spray or regular foam. If regular foam is ineffective or unavailable, use alcohol-resistant foam.

LARGE FIRE: Water spray, fog or regular foam. If regular foam is ineffective or unavailable, use alcohol-resistant foam. Avoid aiming straight or solid streams directly onto the product. If it can be done safely, move undamaged containers away from the area around the fire.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. For petroleum crude oil, do not spray water directly into a breached tank car. This can lead to a dangerous boil over. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2024)

If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Solid streams of water may be ineffective. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use "alcohol" foam, dry chemical or carbon dioxide.

Excerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 50 meters (150 feet) in all directions.

LARGE SPILL: Consider initial downwind evacuation for at least 300 meters (1000 feet).

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

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.

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.

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Use water spray to knock-down vapors.

Personnel protection: Avoid breathing vapors. Keep upwind. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water.

Excerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. A vapor-suppressing foam may be used to reduce vapors. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. Use clean, non-sparking tools to collect absorbed material.

LARGE SPILL: Dike far ahead of liquid spill for later disposal. Water spray may reduce vapor, but may not prevent ignition in closed spaces. (ERG, 2024)

740.0 [ppm]

Excerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:

Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. (ERG, 2024)

Personnel protection: ... Wear appropriate chemical protective gloves, boots, and goggles. Wear positive pressure self-contained breathing apparatus.

Hexyl acetate appears as a colorless liquid with a mild sweet odor. Flash point 113 °F. A moderate fire risk. Inhalation may cause adverse effects. Insoluble in water and very soluble in alcohols and ethers. When heated to high temperatures emits acrid smoke and fumes. Used as a solvent and as a propellant in aerosols.

CBI; Liquid; Dry Powder; Liquid

Colorless liquid with a sweet fruity odor; [HSDB]

colourless liquid with a fruity odour

Colorless liquid

Sweet-fruity, pearl-like odor

Sweet ester odor

BITTERSWEET TASTE SUGGESTIVE OF PEAR

334.4 to 338 °F at 760 mmHg (USCG, 1999)

171.5 °C

170.00 to 172.00 °C. @ 760.00 mm Hg

168-172 °C

-112 °F (USCG, 1999)

-80.9 °C

99 °F (USCG, 1999)

113 °F (45 °C) (Closed cup)

Very soluble in alcohol and ether

In water, 511 mg/L at 25 °C

0.511 mg/mL at 25 °C

soluble in alcohol, ether; insoluble in water

1 ml in 1 ml 95% alcohol (in ethanol)

0.876 (USCG, 1999) - Less dense than water; will float

0.8779 g/cu cm at 15 °C

0.868-0.872

1.32 [mmHg]

1.32 mm Hg at 25 °C

Henry's Law constant = 5.3X10-4 atm-cu m/mol at 25 °C

When heated to decomposition it emits acrid smoke and fumes.

Index of refraction: 1.4092 at 20 °C

1.407-1.411

Boiling point

Diamagnetic susceptibility

Dielectric constant

Excess enthalpy

Fusion temperature

Heat of solution

Heat of sublimation

Magnetic susceptibility

Melting temperature

Mixing enthalpy

Highly flammable. Insoluble in water.

Esters, Sulfate Esters, Phosphate Esters, Thiophosphate Esters, and Borate Esters

Highly Flammable

HEXYL ACETATE is an ester. Esters react with acids to liberate heat along with alcohols and acids. Strong oxidizing acids may cause a vigorous reaction that is sufficiently exothermic to ignite the reaction products. Heat is also generated by the interaction of esters with caustic solutions. Flammable hydrogen is generated by mixing esters with alkali metals and hydrides.

Neurotoxin - Acute solvent syndrome

LD50 Rabbit skin >5 g/kg

LD50 Rat oral 42 g/kg

/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. /Irritating materials/

/SRP:/ Basic Treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Encourage patient to take deep breaths. 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 ... . 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 ... . /Irritating materials/

/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. Early intubation at the first sign of upper airway obstruction may be necessary. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . 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 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 ... . /Irritating materials/

/SIGNS AND SYMPTOMS/ HEADACHE, DIZZINESS, NAUSEA, IRRITATION TO RESPIRATORY PASSAGES. IRRITATES EYES.

/OTHER TOXICITY INFORMATION/ Adult Cosmopepla bimaculata discharge a volatile secretion from paired ventral metathoracic glands (MTG) when disturbed. Collected volatiles were similar in both sexes and consisted of n-tridecane (67%), (E)-2-decenal (12%), (E)-2-decenyl acetate (12%), (E)-2-hexenal (3%), hexyl acetate (2%), n-dodecane (2%), a tridecene isomer (1%), and n-undecane, n-tetradecane, and n-pentadecane (all <1%). In addition, undisturbed males produced a novel insect compound, (E)-8-heneicosene, whose function is unknown. The MTG secretion emerges as an enlarging droplet, which is held in place by a cuticular projection and a pleural scent area consisting of specialized rough cuticle surrounding the gland opening. Insects can selectively discharge from either the right or left gland or both glands simultaneously, can control the amount of fluid ejected, and can resorb the ejected secretion droplet back into the gland reservoir. In feeding trials, killdeer (Charadrius vociferus), starlings (Sturnus vulgaris), robins (Turdus migratorius), and anole lizards (Anolis carolinensis) rejected or demonstrated aversion to feeding on the bugs. Furthermore, bugs that lacked the secretion were more susceptible to predation that bugs with secretion, suggesting that the secretion functions in defense against predators.

/OTHER TOXICITY INFORMATION/ Heteropteran insects often protect themselves from predators with noxious or toxic compounds, especially when these insects occur in aggregations. The predators of heteropteran insects change from small insect predators to large avian predators over time. Thus, a chemical that is deterrent to one type of predator at one point in time may not be deterrent to another type of predator at another point in time. Additionally, these predator deterrent compounds may be used for other functions such as alarm signaling to other conspecifics. Defensive secretion compounds from the adult and the nymph giant mesquite bug (Thasus neocalifornicus: Coreidae) were isolated and identified by gas chromatography-mass spectrometry and NMR. The predominant compounds isolated from the nymph mesquite bugs during a simulated predator encounter were (E)-2-hexenal and 4-oxo-(E)-2-hexenal. In adults, the major compounds released during a simulated predator encounter were hexyl acetate, hexanal, and hexanol. Results from predator bioassays suggest the nymph compounds are more effective at deterring an insect predator than the adult compounds. By using behavioral bioassays, we determined the role of each individual compound in signaling to other mesquite bugs. The presence of the nymph secretion near a usually compact nymph aggregation caused nymph mesquite bugs to disperse but did not affect adults. Conversely, the presence of the adult secretion caused the usually loose adult aggregation to disperse, but it did not affect nymph aggregation. The compounds that elicited nymph behavioral responses were (E)-2-hexenal and 4-oxo-(E)-2-hexenal, while those that elicited adult behavioral responses were hexyl acetate and hexanal. The differences between the chemical composition of nymph and adult defensive secretions and alarm behavior are possibly due to differences in predator guilds.

/OTHER TOXICITY INFORMATION/ ...ANIMALS TOLERATE RELATIVELY LARGE DOSES BOTH BY MOUTH AND BY INHALATION OF VAPOR. THERE APPEARS TO BE SOME ABSORPTION FROM SKIN BUT DIRECT APPLICATION TO SKIN AND EYES CAUSES ONLY MODERATE IRRITATION.

EC50; Species: Pimephales promelas (Fathead Minnow) age 30-31 days, length 19 mm, weight 0.094 g; Conditions: freshwater, flow through, 24.2 (22.5-25.2) °C, pH 7.7 (7.6-7.8), hardness 42.4 mg/L CaCO3, alkalinity 42.0 mg/L CaCO3, dissolved oxygen 84.4 (72.9-91.6) mg/L; Concentration: 5900 ug/L for 24 hr; Effect: behavior, decreased equilibrium

EC50; Species: Pimephales promelas (Fathead Minnow) age 30-31 days, length 19 mm, weight 0.094 g; Conditions: freshwater, flow through, 24.2 (22.5-25.2) °C, pH 7.7 (7.6-7.8), hardness 42.4 mg/L CaCO3, alkalinity 42.0 mg/L CaCO3, dissolved oxygen 84.4 (72.9-91.6) mg/L; Concentration: 4500 ug/L for 48 hr; Effect: behavior, decreased equilibrium

LC50; Species: Pimephales promelas (Fathead Minnow) age 30-31 days, length 19 mm, weight 0.094 g; Conditions: freshwater, flow through, 24.2 (22.5-25.2) °C, pH 7.7 (7.6-7.8), hardness 42.4 mg/L CaCO3, alkalinity 42.0 mg/L CaCO3, dissolved oxygen 84.4 (72.9-91.6) mg/L; Concentration: 6100 ug/L for 24 hr

LC50; Species: Pimephales promelas (Fathead Minnow) age 30-31 days, length 19 mm, weight 0.094 g; Conditions: freshwater, flow through, 24.2 (22.5-25.2) °C, pH 7.7 (7.6-7.8), hardness 42.4 mg/L CaCO3, alkalinity 42.0 mg/L CaCO3, dissolved oxygen 84.4 (72.9-91.6) mg/L; Concentration: 4800 ug/L for 48 hr

LC50; Species: Pimephales promelas (Fathead Minnow) age 30-31 days, length 19.3 mm, weight 0.094 g; Conditions: freshwater, flow through, 24.9 °C, pH 7.7, hardness 42.4 mg/L CaCO3, alkalinity 42.0 mg/L CaCO3, dissolved oxygen 7.0 mg/L; Concentration: 4000 ug/L for 96 hr (95% confidence interval: 3700-4400 ug/L) /99% purity/

n-Hexyl acetate's production and use as a solvent, flavor ingredient and fragrance ingredient may lead to its release to the environment through various waste streams. n-Hexyl acetate occurs naturally in many fruits and may be released into the environment as a plant volatile. If released to air, a vapor pressure of 1.32 mm Hg at 25 °C indicates n-hexyl acetate will exist solely as a vapor in the atmosphere. Vapor-phase n-hexyl acetate 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 2.2 days. n-Hexyl acetate does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight. If released to soil, n-hexyl acetate is expected to have high mobility based upon an estimated Koc of 62. Volatilization from moist soil surfaces is expected to be an important fate process based upon a Henry's Law constant of 5.3X10-4 atm-cu m/mole. n-Hexyl acetate may volatilize from dry soil surfaces based upon its vapor pressure. Although biodegradation data were not available for n-hexyl acetate, studies on structurally similar compounds have shown that, in general, alkyl acetates are biodegradable. If released into water, n-hexyl acetate is expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 5.5 hours and 5.4 days, respectively. An estimated BCF of 34 suggests the potential for bioconcentration in aquatic organisms is moderate. Hydrolysis is expected to occur slowly based upon estimated hydrolysis half-lives of 2 years and 78 days at pH 7 and 8, respectively. Occupational exposure to n-hexyl acetate may occur through inhalation and dermal contact with this compound at workplaces where n-hexyl acetate is produced or used. Monitoring data indicate that the general population may be exposed to n-hexyl acetate via ingestion of food sources that contain this compound. (SRC)

REPORTED FOUND IN FRUITAL AROMAS (EG FRAGARIA VESCA) & ESSENTIAL OILS.

n-Hexyl acetate occurs in many fruits(1-2) and may be released into the environment as a plant volatile(SRC).

n-Hexyl acetate's production and use as a solvent(1), flavor ingredient(2-3) and fragrance ingredient(3) may lead to its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 62(SRC), determined from a structure estimation method(2), indicates that n-hexyl acetate is expected to have high mobility in soil(SRC). Volatilization of n-hexyl acetate from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 5.3X10-4 atm-cu m/mole(3). n-Hexyl acetate is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.32 mm Hg at 25 °C(4). Although biodegradation data were not available for n-hexyl acetate(SRC, 2011), studies on structurally similar compounds(5-7) have shown that, in general, alkyl acetates are biodegradable(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 62(SRC), determined from a structure estimation method(2), indicates that n-hexyl acetate is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon a Henry's Law constant of 5.3X10-4 atm-cu m/mole(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 5.5 hours and 5.4 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 34(SRC), from an estimated log Kow of 2.83(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Hydrolysis is expected to occur slowly based upon estimated hydrolysis half-lives of 2 years and 78 days at pH 7 and 8, respectively(8). Although biodegradation data were not available for n-hexyl acetate(SRC, 2011), studies on structurally similar compounds(9-11) have shown that, in general, alkyl acetates are biodegradable(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), n-hexyl acetate, which has a vapor pressure of 1.32 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase n-hexyl acetate 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 2.2 days(SRC), calculated from its rate constant of 7.4X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). n-Hexyl acetate does not contain chromophores that absorb at wavelengths >290 nm(4) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

Although no biodegradation studies were available for n-hexyl acetate(SRC, 2011), studies on structurally similar compounds(1-3) have shown that, in general, alkyl acetates are biodegradable(SRC).

The rate constant for the vapor-phase reaction of n-hexyl acetate with photochemically-produced hydroxyl radicals has been estimated as 7.4X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 2.2 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). A base-catalyzed second-order hydrolysis rate constant of 0.10 L/mole-sec(SRC) was estimated using a structure estimation method(2); this corresponds to half-lives of 2.1 years and 78 days at pH values of 7 and 8, respectively(2). n-Hexyl acetate does not contain chromophores that absorb at wavelengths >290 nm(3) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 34 was calculated in fish for n-hexyl acetate(SRC), using an estimated log Kow of 2.83(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is moderate(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of n-hexyl acetate can be estimated to be 62(SRC). According to a classification scheme(2), this estimated Koc value suggests that n-hexyl acetate is expected to have high mobility in soil.

The Henry's Law constant for n-hexyl acetate reported as 5.3X10-4 atm-cu m/mole(1). This Henry's Law constant indicates that n-hexyl acetate is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 5.5 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 5.4 days(SRC). n-Hexyl acetate's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). n-Hexyl acetate is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.32 mm Hg(3).

SURFACE WATER: n-Hexyl acetate was detected in the Lee River in England at concentrations of <1 ug/L(1).

n-Hexyl acetate was detected in apricots (4 ug/kg)(1), plums (2 ug/kg and 43 ug/kg)(1) and nectarines (10 ug/kg and 20 ug/kg)(2). n-Hexyl acetate was identified, not quantified, in apples(3,4), kiwi fruit(5) and beef volatiles(6). n-Hexyl acetate was detected in the head space samples of golden delicious apples after 24 hours incubation with pentanoic acid vapors and also in the essential oils(7).

n-Hexyl acetate was reported in the skin and pulp of Queen Anne's pocket melon (Cucumis melo L) at 183 and 175.9 ug/kg equivalent of 2-octanol, respectively(1). n-Hexyl acetate was identified, not quantified, in the head space of intact golden delicious apples(2).

According to the 2006 TSCA Inventory Update Report, the number of workers reasonably likely to be exposed in the industrial manufacturing, processing, and use for n-hexyl acetate is 1000 or greater persons; the data may be greatly underestimated(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 4038 workers (1755 of these were female) were potentially exposed to n-hexyl acetate in the US(1). Occupational exposure to n-hexyl acetate may occur through inhalation and dermal contact with this compound at workplaces where n-hexyl acetate is produced or used. Monitoring data indicate that the general population may be exposed to n-hexyl acetate via ingestion of food sources that contain this compound(SRC).

n-Hexyl acetate was identified, not quantified, in human adipose tissue(1).

EC50; Species: Pimephales promelas (Fathead Minnow) age 30-31 days, length 19 mm, weight 0.094 g; Conditions: freshwater, flow through, 24.2 (22.5-25.2) °C, pH 7.7 (7.6-7.8), hardness 42.4 mg/L CaCO3, alkalinity 42.0 mg/L CaCO3, dissolved oxygen 84.4 (72.9-91.6) mg/L; Concentration: 5900 ug/L for 24 hr; Effect: behavior, decreased equilibrium

EC50; Species: Pimephales promelas (Fathead Minnow) age 30-31 days, length 19 mm, weight 0.094 g; Conditions: freshwater, flow through, 24.2 (22.5-25.2) °C, pH 7.7 (7.6-7.8), hardness 42.4 mg/L CaCO3, alkalinity 42.0 mg/L CaCO3, dissolved oxygen 84.4 (72.9-91.6) mg/L; Concentration: 4500 ug/L for 48 hr; Effect: behavior, decreased equilibrium

LC50; Species: Pimephales promelas (Fathead Minnow) age 30-31 days, length 19 mm, weight 0.094 g; Conditions: freshwater, flow through, 24.2 (22.5-25.2) °C, pH 7.7 (7.6-7.8), hardness 42.4 mg/L CaCO3, alkalinity 42.0 mg/L CaCO3, dissolved oxygen 84.4 (72.9-91.6) mg/L; Concentration: 6100 ug/L for 24 hr

LC50; Species: Pimephales promelas (Fathead Minnow) age 30-31 days, length 19 mm, weight 0.094 g; Conditions: freshwater, flow through, 24.2 (22.5-25.2) °C, pH 7.7 (7.6-7.8), hardness 42.4 mg/L CaCO3, alkalinity 42.0 mg/L CaCO3, dissolved oxygen 84.4 (72.9-91.6) mg/L; Concentration: 4800 ug/L for 48 hr

LC50; Species: Pimephales promelas (Fathead Minnow) age 30-31 days, length 19.3 mm, weight 0.094 g; Conditions: freshwater, flow through, 24.9 °C, pH 7.7, hardness 42.4 mg/L CaCO3, alkalinity 42.0 mg/L CaCO3, dissolved oxygen 7.0 mg/L; Concentration: 4000 ug/L for 96 hr (95% confidence interval: 3700-4400 ug/L) /99% purity/

n-Hexyl acetate's production and use as a solvent, flavor ingredient and fragrance ingredient may lead to its release to the environment through various waste streams. n-Hexyl acetate occurs naturally in many fruits and may be released into the environment as a plant volatile. If released to air, a vapor pressure of 1.32 mm Hg at 25 °C indicates n-hexyl acetate will exist solely as a vapor in the atmosphere. Vapor-phase n-hexyl acetate 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 2.2 days. n-Hexyl acetate does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight. If released to soil, n-hexyl acetate is expected to have high mobility based upon an estimated Koc of 62. Volatilization from moist soil surfaces is expected to be an important fate process based upon a Henry's Law constant of 5.3X10-4 atm-cu m/mole. n-Hexyl acetate may volatilize from dry soil surfaces based upon its vapor pressure. Although biodegradation data were not available for n-hexyl acetate, studies on structurally similar compounds have shown that, in general, alkyl acetates are biodegradable. If released into water, n-hexyl acetate is expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 5.5 hours and 5.4 days, respectively. An estimated BCF of 34 suggests the potential for bioconcentration in aquatic organisms is moderate. Hydrolysis is expected to occur slowly based upon estimated hydrolysis half-lives of 2 years and 78 days at pH 7 and 8, respectively. Occupational exposure to n-hexyl acetate may occur through inhalation and dermal contact with this compound at workplaces where n-hexyl acetate is produced or used. Monitoring data indicate that the general population may be exposed to n-hexyl acetate via ingestion of food sources that contain this compound. (SRC)

REPORTED FOUND IN FRUITAL AROMAS (EG FRAGARIA VESCA) & ESSENTIAL OILS.

n-Hexyl acetate occurs in many fruits(1-2) and may be released into the environment as a plant volatile(SRC).

n-Hexyl acetate's production and use as a solvent(1), flavor ingredient(2-3) and fragrance ingredient(3) may lead to its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 62(SRC), determined from a structure estimation method(2), indicates that n-hexyl acetate is expected to have high mobility in soil(SRC). Volatilization of n-hexyl acetate from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 5.3X10-4 atm-cu m/mole(3). n-Hexyl acetate is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.32 mm Hg at 25 °C(4). Although biodegradation data were not available for n-hexyl acetate(SRC, 2011), studies on structurally similar compounds(5-7) have shown that, in general, alkyl acetates are biodegradable(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 62(SRC), determined from a structure estimation method(2), indicates that n-hexyl acetate is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon a Henry's Law constant of 5.3X10-4 atm-cu m/mole(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 5.5 hours and 5.4 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 34(SRC), from an estimated log Kow of 2.83(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Hydrolysis is expected to occur slowly based upon estimated hydrolysis half-lives of 2 years and 78 days at pH 7 and 8, respectively(8). Although biodegradation data were not available for n-hexyl acetate(SRC, 2011), studies on structurally similar compounds(9-11) have shown that, in general, alkyl acetates are biodegradable(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), n-hexyl acetate, which has a vapor pressure of 1.32 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase n-hexyl acetate 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 2.2 days(SRC), calculated from its rate constant of 7.4X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). n-Hexyl acetate does not contain chromophores that absorb at wavelengths >290 nm(4) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

Although no biodegradation studies were available for n-hexyl acetate(SRC, 2011), studies on structurally similar compounds(1-3) have shown that, in general, alkyl acetates are biodegradable(SRC).

The rate constant for the vapor-phase reaction of n-hexyl acetate with photochemically-produced hydroxyl radicals has been estimated as 7.4X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 2.2 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). A base-catalyzed second-order hydrolysis rate constant of 0.10 L/mole-sec(SRC) was estimated using a structure estimation method(2); this corresponds to half-lives of 2.1 years and 78 days at pH values of 7 and 8, respectively(2). n-Hexyl acetate does not contain chromophores that absorb at wavelengths >290 nm(3) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

An estimated BCF of 34 was calculated in fish for n-hexyl acetate(SRC), using an estimated log Kow of 2.83(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is moderate(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of n-hexyl acetate can be estimated to be 62(SRC). According to a classification scheme(2), this estimated Koc value suggests that n-hexyl acetate is expected to have high mobility in soil.

The Henry's Law constant for n-hexyl acetate reported as 5.3X10-4 atm-cu m/mole(1). This Henry's Law constant indicates that n-hexyl acetate is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 5.5 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 5.4 days(SRC). n-Hexyl acetate's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). n-Hexyl acetate is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.32 mm Hg(3).

SURFACE WATER: n-Hexyl acetate was detected in the Lee River in England at concentrations of <1 ug/L(1).

n-Hexyl acetate was detected in apricots (4 ug/kg)(1), plums (2 ug/kg and 43 ug/kg)(1) and nectarines (10 ug/kg and 20 ug/kg)(2). n-Hexyl acetate was identified, not quantified, in apples(3,4), kiwi fruit(5) and beef volatiles(6). n-Hexyl acetate was detected in the head space samples of golden delicious apples after 24 hours incubation with pentanoic acid vapors and also in the essential oils(7).

n-Hexyl acetate was reported in the skin and pulp of Queen Anne's pocket melon (Cucumis melo L) at 183 and 175.9 ug/kg equivalent of 2-octanol, respectively(1). n-Hexyl acetate was identified, not quantified, in the head space of intact golden delicious apples(2).

According to the 2006 TSCA Inventory Update Report, the number of workers reasonably likely to be exposed in the industrial manufacturing, processing, and use for n-hexyl acetate is 1000 or greater persons; the data may be greatly underestimated(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 4038 workers (1755 of these were female) were potentially exposed to n-hexyl acetate in the US(1). Occupational exposure to n-hexyl acetate may occur through inhalation and dermal contact with this compound at workplaces where n-hexyl acetate is produced or used. Monitoring data indicate that the general population may be exposed to n-hexyl acetate via ingestion of food sources that contain this compound(SRC).

n-Hexyl acetate was identified, not quantified, in human adipose tissue(1).

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.

Flammable Liquid