3-Acetyl-6-methyl-2H-pyran-2,4(3H)-dione

168.148

168.15

208-293-9

760135|8770

DTXSID6020014

NEEDLES FROM WATER, RHOMBIC NEEDLES OR PRISMS FROM ALCOHOL|WHITE TO CREAM CRYSTALLINE POWDER|COLORLESS POWDER|Colorless crystals

2932999099

60.4

0.3

white powder

1.3±0.1 g/cm3

109 °C

269.9 °C @ Press: 760 Torr

157 DEG C; 315 DEG F (OPEN CUP)

1.490

water solubility = 690 mg/l @ 25 deg C

0-6ºC

0.001 hPa (20 °C)

5.8 (AIR= 1)

LD50 orally in rats: 1000 mg/kg (Spencer)

ODORLESS

TASTELESS

HIGHLY REACTIVE

366 °C (690 °F)

14,663.8 gcal/gmol

II; III

4.1

NONH for all modes of transport

1

R22

S22

UP8050000

Xn:Harmful;

Stable. Incompatible with oxidizing agents, bases, reducing agents.

P301 + P312 + P330

H302

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

HIGHLY REACTIVE

Dehydroacetic acid is a food additive permitted for direct addition to food for human consumption, as long as 1) the quantity added to food does not exceed the amount reasonably required to accomplish its intended physical, nutritive, or other technical effect in food, and 2) when intended for use in or on food it is of appropriate food grade and is prepared and handled as a food ingredient.|Dehydroacetic acid is an indirect food additive for use as a component of adhesives.

|Warning|H302: Harmful if swallowed [Warning Acute toxicity, oral]|P264, P270, P301+P312, P330, and P501

SLIGHT

WATER OR FOAM MAY CAUSE FROTHING.

No primary or allergic skin reactions

| 1 - Materials that, under emergency conditions, can cause significant irritation.| 1 - Materials that must be preheated before ignition can occur. Materials require considerable preheating, under all ambient temperature conditions, before ignition and combustion can occur.| 0 - Materials that in themselves are normally stable, even under fire conditions.

LD50 Rat oral 1,000 mg/kg|LD50 Rat oral 570 mg/kg /Dehydroacetic acid, sodium salt hydrate/

Dehydroacetic acid is of anthropogenic origin, and is not known to be produced by natural sources. (SRC)

Dehydroacetic acid's production and use in organic syntheses, as a plasticizer, bactericide, in anti-enzyme toothpastes(1), and as a fungicide in cosmetics and on processed fruits and vegetables(2) may result in its release to the environment(SRC).

TERRESTRIAL FATE: Based on a recommended classification scheme(1), an estimated Koc value of 120(SRC), determined from a measured water solubility of 690 mg/l(2) and a recommended regression-derived equation(3), indicates that dehydroacetic acid is expected to have high mobility in soil(SRC). Volatilization of dehydroacetic acid from moist soil surfaces is not expected to be important(SRC) given an estimated Henry's Law constant of 3.4X10-7 atm-cu m/mole(SRC), determined from its measured water solubility, 690 mg/l(2), and extrapolated vapor pressure, 1.1X10-3 mm Hg(4). Dehydroacetic acid is not expected to volatilize from dry soil surfaces based on its extrapolated vapor pressure(4). Biodegradation of dehydroacetic acid in soil may be important(SRC), based on its biodegradation in standard biodegradability tests(2,5).|AQUATIC FATE: Based on a recommended classification scheme(1), an estimated Koc value of 120(SRC), a measured water solubility of 690 mg/l(2) and a recommended regression-derived equation(3), indicates that dehydroacetic acid is not expected to adsorb to suspended solids and sediment in water(SRC). Dehydroacetic acid is not expected to volatilize from water surfaces(3,SRC) based on an estimated Henry's Law constant of 3.4X10-7 atm-cu m/mole(SRC), from its measured water solubility, 690 mg/l(2), and extrapolated vapor pressure, 1.1X10-3 mm Hg(4). According to a classification scheme(5), an estimated BCF value of 15(3,SRC), from a measured water solubility(2), suggests that bioconcentration in aquatic organisms is low(SRC). A biodegradation study on dehydroacetic acid, based on BOD measurements, using an activated sludge seed, and an initial chemical concentration of 100 mg/l indicated 84% biodegradation after 2 weeks(2). Dehydroacetic acid was observed to degrade in six aerobic biodegradation tests (coupled units test, Zahn-Wellens test, MITI test, Sturm CO2 evolution test, OECD screening test, and closed bottle test)(6).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dehydroacetic acid, which has an extrapolated vapor pressure of 1.1X10-3 mm Hg at 25 °C(2,SRC), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase dehydroacetic acid 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 about 4.9 hours(3,SRC). The rate constant for the vapor-phase reaction of dehydroacetic acid with ozone has been estimated as 1.1X10-17 cu cm/molecule-sec at 25 °C(3,SRC). This corresponds to an atmospheric half-life of about 1.0 day at an atmospheric ozone concn of 7X10+11 cu cm/molecule-sec at 25 °C(3,SRC).

The rate constant for the vapor-phase reaction of dehydroacetic acid with photochemically-produced hydroxyl radicals has been estimated as 7.9X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1,SRC). This corresponds to an atmospheric half-life of about 4.9 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1,SRC). The rate constant for the vapor-phase reaction of dehydroacetic acid with ozone has been estimated as 1.1X10-17 cu cm/molecule-sec at 25 °C(1,SRC). This corresponds to an atmospheric half-life of about 1.0 day at an atmospheric ozone concn of 7X10+11 cu cm/molecule-sec at 25 °C(1,SRC). Alpha, beta-unsaturated ketones absorb light in the environmental spectrum(2) suggesting dehydroacetic acid may be susceptible to direct photolysis(SRC).

An estimated BCF value of 15 was calculated for dehydroacetic acid(SRC), using a measured water solubility of 690 mg/l(1) and a recommended regression-derived equation(2). According to a classification scheme(3), this BCF value suggests that bioconcentration in aquatic organisms is low(SRC).

The Koc of dehydroacetic acid is estimated as approximately 120(SRC), using a measured water solubility of 690 mg/l(1) and a regression-derived equation(2,SRC). According to a recommended classification scheme(3), this estimated Koc value suggests that dehydroacetic acid is expected to have high mobility in soil(SRC).

The Henry's Law constant for dehydroacetic acid is estimated as 3.4X10-7 atm-cu m/mole(SRC) from its extrapolated vapor pressure, 1.1X10-3 mm Hg(1), and measured water solubility, 690 mg/l(2). This value indicates that dehydroacetic acid will volatilize very slowly from water surfaces(3,SRC). 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) is estimated as approximately 140 days(3,SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec) is estimated as approximately 1030 days(3,SRC). Dehydroacetic acid's Henry's Law constant(1,2,SRC) indicates that volatilization from moist soil surfaces is not expected to be important(SRC). Dehydroacetic acid is not expected to volatilize from dry soil surfaces based on an extrapolated vapor pressure of 1.1X10-3 mm Hg(1,SRC).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 925 workers (679 of these are female) are potentially exposed to dehydroacetic acid in the US(1). Occupational exposure may be through inhalation of dust particles and dermal contact with this compound at workplaces where dehydroacetic acid is produced or used(SRC). The general population may be exposed to dehydroacetic acid via ingestion of food or dermal contact with consumer products containing this compound(SRC).

METABOLITES IN RABBIT ARE: TRIACETIC ACID LACTONE, A HYDROXY DHA & POSSIBLY THE SALT OF TRIACETIC ACID LACTONE 3-CARBOXYLIC ACID.|...NATURAL PRODUCT OF ADRENAL STEROID METABOLISM...

CAUSES IMPAIRED KIDNEY FUNCTION. LARGE DOSES CAN CAUSE VOMITING, ATAXIA, CONVULSIONS.|NO PRIMARY OR ALLERGIC SKIN REACTIONS. HUMANS INGESTED 0.01 G/KG DAILY FOR 150 DAYS WITHOUT OBSERVABLE ILL-EFFECTS.

dehydroacetic acid

GRADES: TECHNICAL, FCC.

2H-Pyran-2,4(3H)-dione, 3-acetyl-6-methyl-: ACTIVE|TO INHIBIT MICROBIOLOGICAL GROWTH (0.01-0.5%) IN OR ON PHARMACEUTICALS INCL SEMEN DILUTERS, FOODS, & COSMETICS. ISRAELIS ARE TRYING TO DEVELOP INEXPENSIVE STABLE DERIVATIVE FOR USE IN FEED. ...IT PREVENTS POULTRY DEATH CAUSED BY EXCESSIVE HEAT OR COLD STRESSES.

A FLUOROMETRIC METHOD FOR DETECTION OF DEHYDROACETIC ACID IN MASCARAS IS BASED ON FORMATION OF THE FLUOROPHORE GAMMA-PYROXONIUM BORATE. STUDIES WERE CONDUCTED AT 0.1, 0.05 & 0.01% LEVELS. RECOVERIES RANGED FROM 88 TO 106% WITH AN OVERALL AVG OF 99%.|SALICYLALDEHYDE QUALITATIVE TEST FOR DEHYDROACETIC ACID IN CHEESE BY COLORIMETRIC DETERMINATION. 20.053. QUANTITATIVE METHOD FOR AMT IN CHEESE DETERMINED SPECTROPHOTOMETRICALLY AT 307 NM.|Qualitative Test. AOAC Method Number 953.12. Dehydroacetic Acid in Cheese.|Spectrophotometric Method. AOAC Method Number 953.13. Dehydroacetic Acid in Cheese.

EPA Safer Chemical Functional Use Classes -> Preservatives and Antioxidants|Safer Chemical Classes -> Yellow triangle - The chemical has met Safer Choice Criteria for its functional ingredient-class, but has some hazard profile issues|Cosmetics -> Preservative