2,3-Pentanedione

100.12

100.12

1699638

209-984-8

K4WBE45SCM

7613

DTXSID6051435

Yellow liquid|Yellow to yellow-green liquid

29141990

34.1

0.1

very deep green-yellow Liquid

0.9571 g/cm³ @ Temp: 17 °C

-52 °C

108 °C

66 °F

1.395

H2O: 60 g/L (15 ºC)

2-8°C

28.5 hPa (20 °C)

LD50 orally in Rabbit: 3000 mg/kg LD50 dermal Rabbit > 2500 mg/kg

1.8-10.9%(V)

Somewhat sweet odor similar to quinone ... Detection: 20 ppb. Aroma characteristics at 1.0%: buttery diacytl-like, fermented dairy and creamy, popcorn buttery

Penetrating buttery taste on dilution...Taste characteristics at 1 to 5 ppm: sweet buttery, creamy, cheesy, slightly toasted dairy, with a rich baked goods nuance and good mouth feel

Henry's Law constant = 2.62X10-7 atm-cu m/mol at 25 °C (est)

Hydroxyl radical reaction rate constant = 1.3X10-12 cu cm/molec-sec at 25 °C (est)|Direct photolysis rate constant = 3.6X10-5 cu cm/molecule-sec

0.955-0.959 (15/4 °C)

Ⅱ

3

UN 1224 3/PG 2

1

11-36/37/38

16-26-36-37/39

SA1850000

F,Xi

Stable. Highly flammable - store cool. Incompatible with strong oxidizing agents, reducing agents, strong bases.

P210-P261-P305 + P351 + P338

H225-H315-H319-H335

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.|Product: Burn in a chemical incinerator equipped with an afterburner and scrubber but exert extra care in igniting as this material is highly flammable. Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material; Contaminated packaging: Dispose of as unused product.

Incompatible materials: Oxidizing agents, reducing agents, strong bases.

2,3-Pentanedione is a food additive permitted for direct addition to food for human consumption as a synthetic flavoring substance and adjuvant in accordance with the following conditions: a) they are used in the minimum quantity required to produce their intended effect, and otherwise in accordance with all the principles of good manufacturing practice, and b) they consist of one or more of the following, used alone or in combination with flavoring substances and adjuvants generally recognized as safe in food, prior-sanctioned for such use, or regulated by an appropriate section in this part.

|Danger|H225 (99.94%): Highly Flammable liquid and vapor [Danger Flammable liquids]|P210, P233, P240, P241, P242, P243, P260, P261, P272, P280, P302+P352, P303+P361+P353, P305+P351+P338, P310, P314, P321, P333+P313, P363, P370+P378, P403+P235, and P501|Aggregated GHS information provided by 1608 companies from 26 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H225: Highly Flammable liquid and vapor [Danger Flammable liquids]|P210, P233, P240, P241, P242, P243, P261, P264, P271, P280, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P370+P378, P403+P233, P403+P235, P405, and P501

Eye/face protection: Face shield and safety glasses. Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).|Skin protection: Handle with gloves.|Body Protection: Impervious clothing. Flame retardant antistatic protective clothing. The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.|Respiratory protection: Where risk assessment shows air-purifying respirators are appropriate use a full-face respirator with multipurpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls. If the respirator is the sole means of protection, use a full-face supplied air respirator. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).

Flammable liquid

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical, or carbon dioxide.|Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.|Use water spray to cool unopened containers.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment, and emergency procedures: Use personal protective equipment. Avoid breathing vapors, mist, or gas. Ensure adequate ventilation. Remove all sources of ignition. Evacuate personnel to safe areas. Beware of vapors accumulating to form explosive concentrations. Vapors can accumulate in low areas. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Methods and materials for containment and cleaning up: Contain spillage, and then collect with an electrically protected vacuum cleaner or by wet-brushing and place in container for disposal according to local regulations.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment, and emergency procedures: Use personal protective equipment. Avoid breathing vapors, mist, or gas. Ensure adequate ventilation. Remove all sources of ignition. Evacuate personnel to safe areas. Beware of vapors accumulating to form explosive concentrations. Vapors can accumulate in low areas. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains.|Precautions for safe handling: Avoid contact with skin and eyes. Avoid inhalation of vapor or mist. Use explosion-proof equipment. Keep away from sources of ignition - No smoking. Take measures to prevent the build up of electrostatic charge.|Appropriate engineering controls: Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.|Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.|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.

A skin irritant.

URBAN/SUBURBAN: 2,3-Pentanedione has been detected in summer and winter ambient air samples at concentrations of 11.1 and 8.1 ng/cu m, respectively, collected in 2006/2007 near busy roadways in Roseville, CA(2).

2,3-Pentanedione has been identified in both tobacco smoke and tobacco substitute smoke and in tobacco collected from cigarettes(1). 2,3-Pentanedione was detected, not quantified, in 1 of 44 emission samples from furniture with wood-based surface coatings(2).|... 2,3-Pentanedione /was/ detected in 23 ... of the 51 /e-cigarette/ flavors tested at concentrations up to 64 ... ug/e-cigarette, respectively. ...

IDENTIFICATION AND USE: 2,3-Pentanedione is a yellow liquid. It is used as flavoring agent (butter flavoring) including many e-cigarette brands. HUMAN EXPOSURE AND TOXICITY: Inhalation of butter flavoring by workers in the microwave popcorn industry may result in "popcorn workers' lung." Cultured human bronchial/tracheal epithelial cells (NHBEs) were exposed for 6 hours to diacetyl or 2,3-pentanedione vapors (25 or >/= 60 ppm) and the effects on short circuit current and transepithelial resistance (Rt) were measured. Immediately after exposure to 25 ppm both flavorings reduced Na+ transport, without affecting Cl- transport or Na+,K+-pump activity. Concentrations (100-360 ppm) of diacetyl and 2,3-pentanedione reported to give rise in vivo to epithelial damage, and 60 ppm, caused death of NHBEs 0 hours post-exposure. The results indicate that ion transport is inhibited transiently in airway epithelial cells by lower concentrations of the flavorings than those that result in morphological changes of the cells in vivo or in vitro. ANIMAL STUDIES: Rats that inhaled air, 2,3-pentanedione (112, 241, 318, or 354 ppm) for 6 hours were sacrificed the following day. Rats inhaling 2,3-pentanedione developed necrotizing rhinitis, tracheitis, and bronchitis. To investigate delayed toxicity, additional rats inhaled 318 (range, 317.9-318.9) ppm 2,3-pentanedione for 6 hours and were sacrificed 0 to 2, 12 to 14, or 18 to 20 hours after exposure. Respiratory epithelial injury in the upper nose involved both apoptosis and necrosis, which progressed through 12 to 14 hours after exposure. Olfactory neuroepithelial injury included loss of olfactory neurons that showed reduced expression of the 2,3-pentanedione-metabolizing enzyme, dicarbonyl/L-xylulose reductase, relative to sustentacular cells. Caspase 3 activation occasionally involved olfactory nerve bundles that synapse in the olfactory bulb (OB). An additional group of rats inhaling 270 ppm 2,3-pentanedione for 6 hours 41 minutes showed increased expression of IL-6 and nitric oxide synthase-2 and decreased expression of vascular endothelial growth factor A in the OB, striatum, hippocampus, and cerebellum using real-time PCR. Claudin-1 expression increased in the OB and striatum. In other experiment, male and female rats and mice were exposed to 0, 50, 100, or 200 ppm 2,3-pentanedione 6 hr/d, 5 d/wk for up to 2 weeks. Bronchoalveolar lavage fluid (BALF) was collected after 1, 3, 5, and 10 exposures, and histopathology was evaluated after 12 exposures. MCP-1, MCP-3, CRP, FGF-9, fibrinogen, and OSM were increased 2- to 9-fold in BALF of rats exposed for 5 and 10 days to 200 ppm. In mice, only fibrinogen was increased after 5 exposures to 200 ppm. The epithelium lining the respiratory tract was the site of toxicity in all mice and rats exposed to 200 ppm. Significantly, 2,3-pentanedione also caused both intraluminal and intramural fibrotic airway lesions in rats. In third experiment, rats exposed to 150 or 200 ppm 2,3-pentanedione developed bronchial fibrosis. In mice, 2,3-pentanedione was not a dermal irritant when tested at concentrations up to 50%. However, concentration-dependent increases in lymphocyte proliferation were observed following exposure to 2,3-pentanedione in mice.

LD50 Rat oral 3000 mg/kg

2,3-Pentanedione was identified in essential oil of Finnish pine. It has been reported found in several fruits, vegetables, and nuts(1).

2,3-Pentanedione's production and use as a flavor agent(1) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 1(SRC), determined from a structure estimation method(2), indicates that 2,3-pentanedione is expected to have very high mobility in soil(SRC). Volatilization of 2,3-pentanedione from moist soil surfaces may be an important fate process(SRC) given its Henry's Law constant estimated as 3.95X10-5 atm-cu m/mole(2) based upon its vapor pressure, 20 mm Hg(3), and water solubility, 6.67X10+4 mg/L(2). 2,3-Pentanedione is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 20 mm Hg at 20 °C(3). Biodegradation data in soil were not available(SRC, 2016). In a Warburg Repirometry test 2,3- pentanedione was toxic to the microogansims(4).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 1(SRC), determined from a structure estimation method(2), indicates that 2,3-pentanedione is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces may be expected(3) based upon an estimated Henry's Law constant of 3.95X10-5 atm-cu m/mole(2), derived from its vapor pressure, 20 mm Hg(4), and water solubility, 6.67X10+4 mg/L(2). Using this Henry's Law constant and an estimation method(2), volatilization half-lives for a model river and model lake are 16 hours and 11 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 3(SRC), from an estimated log Kow of -0.85(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data in water were not available(SRC, 2016). In a Warburg Repirometry test 2,3-pentanedione was toxic to the microogansims(6).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2,3-pentanedione, which has a vapor pressure of 20 mm Hg at 20 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 2,3-pentanedione 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 12 days(SRC), calculated from its rate constant of 1.33X10-12 cu cm/molecule-sec at 25 °C(3). 2,3-Pentanedione contains chromophores that absorb at wavelengths >290(4) and, therefore, is expected to be susceptible to direct photolysis by sunlight(SRC). The half-life for the direct photolysis of 2,3-pentanedione is 3 hours(5).

The rate constant for the vapor-phase reaction of 2,3-pentanedione with photochemically-produced hydroxyl radicals has been estimated as 1.33X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 12 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(2). 2,3-Pentanedione is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). 2,3-Pentanedione contains chromophores that absorb at wavelengths >290 up to approximately 475 nm with a maximum around 430 nm(4) and, therefore, is expected to be susceptible to direct photolysis by sunlight(SRC). The half-life for the direct photolysis of 2,3-pentanedione, calculated from the measured rate constant of 3.6X10-5 cu cm/molecule-sec(5), is 3 hours(SRC).

An estimated BCF of 3 was calculated in fish for 2,3-pentanedione(SRC), using an estimated log Kow of -0.85(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of 2,3-pentanedione can be estimated to be 1(SRC). According to a classification scheme(2), this estimated Koc value suggests that 2,3-pentanedione is expected to have very high mobility in soil.

The Henry's Law constant for 2,3-pentanedione is estimated as 3.95X10-5 atm-cu m/mole(SRC) derived from its vapor pressure, 20 mm Hg(1), and water solubility, 6.67X10+4 mg/L(2). This Henry's Law constant indicates that 2,3-pentanedione is expected to volatilize from water surfaces(3). 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)(3) is estimated as 16 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)(3) is estimated as 11 days(SRC). 2,3-Pentanedione's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). The potential for volatilization of 2,3-pentanedione from dry soil surfaces may exist based upon its vapor pressure(1).

2,3-Pentanedione has been detected, not quantified in peach, wheat bread, cocoa, coffee, black tea, roasted filbert, roasted peanut, roasted almonds, pecans, soybean, malt, peated malt, chayote, peas, cooked potato, tomato, boiled egg, cooked chicken and fat, cooked beef and pork, beer, cognac, sweet corn, okra, mate and soursop(1). 2,3-Pentanedione has been identified, but not quantified, in pork liver(1), chicken, beef, and pork meat volatiles(2) and cooked beef(3).|2,3-Pentanedione has been reported as a coffee aroma constituent at concentrations ranging between 9.0 nmol - 0.9 mmol (1). 2,3-Pentanedione has been reported as a volatile compound of cooked sweet corn products with concentrations of 5 ppb in canned cream and canned kernel corn, and <2 ppb in frozen kernel and fresh kernel corn(2). 2,3-Pentanedione has been reported as a volatile compound of microwave popped corn kernels at concentrations ranging from 200 to 380 ug/kg(3). 2,3-Pentanedione has been reported as a volatile compound of commercial rice cakes at concentrations ranging from 91 to 250 ppb(4). 2,3-Pentanedione has been reported as an aroma constituent in raw and roasted earth almonds (Cyperus esculentus)(5). 2,3-Pentanedione was identified but not quantified in frankfurters(6).

2,3-Pentanedione has been identified in yogurt and butter (1).

Occupational exposure to 2,3-pentanedione may occur through inhalation and dermal contact with this compound at workplaces where 2,3-pentanedione is produced or used. Monitoring data indicate that the general population may be exposed to 2,3-pentanedione via inhalation of cigarette smoke and ingestion of food. (SRC)|BACKGROUND: There are > 7,000 e-cigarette flavors currently marketed. Flavoring chemicals gained notoriety in the early 2000s when inhalation exposure of the flavoring chemical diacetyl was found to be associated with a disease that became known as "popcorn lung." There has been limited research on flavoring chemicals in e-cigarettes. OBJECTIVE: We aimed to determine if the flavoring chemical diacetyl and two other high-priority flavoring chemicals, 2,3-pentanedione and acetoin, are present in a convenience sample of flavored e-cigarettes. METHODS: We selected 51 types of flavored e-cigarettes sold by leading e-cigarette brands and flavors we deemed were appealing to youth. E-cigarette contents were fully discharged and the air stream was captured and analyzed for total mass of diacetyl, 2,3-pentanedione, and acetoin, according to OSHA method 1012. RESULTS: At least one flavoring chemical was detected in 47 of 51 unique flavors tested. Diacetyl was detected above the laboratory limit of detection in 39 of the 51 flavors tested, ranging from below the limit of quantification to 239 ug/e-cigarette. 2,3-Pentanedione and acetoin were detected in 23 and 46 of the 51 flavors tested at concentrations up to 64 and 529 ug/e-cigarette, respectively. CONCLUSION: Because of the associations between diacetyl and bronchiolitis obliterans and other severe respiratory diseases observed in workers, urgent action is recommended to further evaluate this potentially widespread exposure via flavored e-cigarettes.

We developed a system to expose cultured human bronchial/tracheal epithelial cells (NHBEs) to flavoring vapors. NHBEs were exposed for 6 hr to diacetyl or 2,3-pentanedione vapors (25 or >/= 60 ppm)... Analysis of the basolateral medium indicated that NHBEs metabolize diacetyl and 2,3-pentanedione to acetoin and 2-hydroxy-3-pentanone, respectively.

/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 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.|/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . For 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. Administer activated charcoal ... . /Ketones and related compounds/|/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag-valve-mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Ketones and related compounds/

/ALTERNATIVE and IN VITRO TESTS/ Inhalation of butter flavoring by workers in the microwave popcorn industry may result in "popcorn workers' lung." In previous in vivo studies rats exposed for 6 hr to vapor from the flavoring agents, diacetyl and 2,3-pentanedione, acquired flavoring concentration-dependent damage of the upper airway epithelium and airway hyporeactivity to inhaled methacholine. Because ion transport is essential for lung fluid balance, we hypothesized that alterations in ion transport may be an early manifestation of butter flavoring-induced toxicity. We developed a system to expose cultured human bronchial/tracheal epithelial cells (NHBEs) to flavoring vapors. NHBEs were exposed for 6 hr to diacetyl or 2,3-pentanedione vapors (25 or >/= 60 ppm) and the effects on short circuit current and transepithelial resistance (Rt) were measured. Immediately after exposure to 25 ppm both flavorings reduced Na+ transport, without affecting Cl- transport or Na+,K+-pump activity. Rt was unaffected. Na+ transport recovered 18 hr after exposure. Concentrations (100-360 ppm) of diacetyl and 2,3-pentanedione reported earlier to give rise in vivo to epithelial damage, and 60 ppm, caused death of NHBEs 0 hr (immediately) post-exposure. Analysis of the basolateral medium indicated that NHBEs metabolize diacetyl and 2,3-pentanedione to acetoin and 2-hydroxy-3-pentanone, respectively. The results indicate that ion transport is inhibited transiently in airway epithelial cells by lower concentrations of the flavorings than those that result in morphological changes of the cells in vivo or in vitro.|/OTHER TOXICITY INFORMATION/ Over the last decade, concerns have been raised about potential respiratory health effects associated with occupational exposure to the flavoring additives diacetyl and 2,3-pentanedione. Both of these diketones are also natural components of many foods and beverages, including roasted coffee. To date, there are no published studies characterizing workplace exposures to these diketones during commercial roasting and grinding of unflavored coffee beans. In this study, we measured naturally occurring diacetyl, 2,3-pentanedione, and respirable dust at a facility that roasts and grinds coffee beans with no added flavoring agents. Sampling was conducted over the course of three roasting batches and three grinding batches at varying distances from a commercial roaster and grinder. The three batches consisted of lightly roasted soft beans, lightly roasted hard beans, and dark roasted hard beans. Roasting occurred for 37 to 41 min, and the grinding process took between 8 and 11 min. Diacetyl, 2,3-pentanedione, and respirable dust concentrations measured during roasting ranged from less than the limit of detection (

2,3-pentanedione

Grade: 99%

2,3-Pentanedione: ACTIVE

Method: OSHA 1016; Procedure: chromatography using a flame ionization detector; Analyte: 2,3-pentanedione; Matrix: air; Detection Limit: 9.3 ppb (38 ug/cu m).

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