4-Hydroxybenzoic acid

138.12

138.12

970950

202-804-9

JG8Z55Y12H

4961

DTXSID3026647

White granular crystalline powder consisting of monoclinic prisms

29182930

57.5

1.6

White to ivory Crystalline Powder

1.46 g/cm³ @ Temp: 25 °C

214.5 °C

336.2°C at 760 mmHg

199 °C

1.616

H2O: 5 g/L (20 ºC);methanol: soluble 5%, clear to slightly hazy, colorless to faintly yellow

Refrigerator

1.9X10-7 mm Hg at 25 deg C /Extrapolated/

LD50 orally in Rabbit: > 5000 mg/kg

Henry's Law constant= 7.2X10-12 atm-cu m/mole at 25 °C /Estimated/

pKa = 4.54|K1=3.3X10-5; K2=4.8X10-10 at 19 °C

121.6 Ų [M-H]-

Hydroxyl radical reaction rate constant= 1.3X10-11 cu cm/molecule-sec at 25 °C /Estimated/

NONH for all modes of transport

1

36-36/37/38

26-37/39-36

DH1925000

Xi

Stable under normal temperatures and pressures.

P261-P305 + P351 + P338

H315-H319-H335

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure 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, aquatic, and plant life; and conformance with environmental and public health regulations.

|Danger|H315 (15.03%): Causes skin irritation [Warning Skin corrosion/irritation]|P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P310, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, and P501|Aggregated GHS information provided by 348 companies from 23 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

This action promulgates standards of performance for equipment leaks of Volatile Organic Compounds (VOC) in the Synthetic Organic Chemical Manufacturing Industry (SOCMI). The intended effect of these standards is to require all newly constructed, modified, and reconstructed SOCMI process units to use the best demonstrated system of continuous emission reduction for equipment leaks of VOC, considering costs, non air quality health and environmental impact and energy requirements. 4-Hydroxybenzoic acid is produced, as an intermediate or a final product, by process units covered under this subpart.

Night soil treatment plant effluents collected on two occasions in Japan in 1975 contained 4-hydroxybenzoic acid at 2.0 and 2.5 ug/L(1). Incinerating plant effluent collected in Japan in 1975 contained 4-hydroxybenzoic acid at a concentration of 6.5 ug/L(1).

SOIL: A peat soil contained 4-hydroxybenzoic acid at a concentration of 265 to 727 ug/100 gm dry soil(1). 4-Hydroxybenzoic acid dominated the other phenolic carboxylic acids present in soil samples collected from the McMurdo Sound region of the Antarctic(2). A composite of soil samples collected in a residential district of Tokyo, Japan, between February 1976 and January 1978, contained 4-hydroxybenzoic acid at a concentration of 4.2 ug/g dry soil(3). 4-Hydroxybenzoic acid concentrations in 5 freshwater sediment samples ranged from 3.47 to 133 ug/g dry weight(4).|SEDIMENT: 4-Hydroxybenzoic acid dominated the other phenolic carboxylic acids present in sediment samples collected from the McMurdo Sound region of the Antarctic(1). Sediments collected from Lake Haruna, Tama river, Komagari reservoir, Yatsuse river, and the Gulf of Mexico contained 4-hydroxybenzoic acid at 14, 1.2, 7.9, 16, and 0.51 ug/g dry sediment(2).

URBAN/SUBURBAN: Aerosol samples collected in April 1985 approximately 60 km northeast of Tokyo in a suburban area surrounded by agricultural fields and forests contained unreported concentrations of 4-hydroxybenzoic acid(1). 24-Hour air samples collected from two urban sites in the San Joaquin valley, CA from December 5, 1995 to January 6, 1996 contained 4-hydroxybenzoic acid at 7.8(Bakersfield, CA) and 12 (Fresno, CA) ng/cu m(2). Atmospheric fallout samples collected in a residential district of Tokyo, Japan, between February 1976 and January 1978, contained 4-hydroxybenzoic acid at concentrations ranging from 0.3 to 4.7 ug/cu m/day(3).|RURAL/REMOTE: 24-Hour air samples collected from the Kern Wildlife refuge in the San Joaquin valley, CA, from December 5, 1995 to January 6, 1996 contained 4-hydroxybenzoic acid at 0.6 ng/cu m(1).

LD50 Mouse oral 2200 mg/kg|LD50 Mouse ip 210 mg/kg|LD50 Mouse sc 1050 mg/kg

Phenolic acids, including 4-hydroxybenzoic acid, are widely distributed in vascular plants(1).

4-Hydroxybenzoic acid's production and use as a chemical intermediate, in synthetic drugs, and as a food preservative (up to 0.1% approved by the FDA)(1) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 142, 20, and 14(2), indicate that 4-hydroxybenzoic acid is expected to have high to very high mobility in soil(SRC). Volatilization of 4-hydroxybenzoic acid from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 7.2X10-12 atm-cu m/mole(SRC), derived from its vapor pressure, 1.9X10-7 mm Hg(3), and water solubility, 5000 mg/L(4). In addition, the pKa of 4-hydroxybenzoic acid is 4.54(5), indicating that this compound will primarily exist in anion form in the environment and will not volatilize from moist soil surfaces(SRC). 4-Hydroxybenzoic acid is not expected to volatilize from dry soil surfaces(SRC) based upon its extrapolated vapor pressure value(3). Biodegradation of 4-hydroxybenzoic acid is expected to occur in aerobic and anaerobic soil environments based on both screening and microcosm studies (SRC). In aquifer sediment, from 34 to 70% mineralization was reported under aerobic conditions in 6 days(6). Under anaerobic conditions, 4-hydroxybenzoic acid was completely degraded in river sediments within 23 to 59 days(7).|AQUATIC FATE: Based on a classification scheme(1), Koc values of 142, 20, and 14(2)indicate that 4-hydroxybenzoic acid is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 7.2X10-12 atm-cu m/mole(SRC), derived from its vapor pressure, 1.9X10-7 mm Hg(4) and water solubility, 5000 mg/L(5). The pKa of 4-hydroxybenzoic acid is 4.54(9), indicating that this compound will primarily exist in anion form and anions generally do not adsorb more strongly to suspended solids and sediment than their neutral counterparts(6). According to a classification scheme(7), an estimated BCF of 9(SRC), from its log Kow(8) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low (SRC). Biodegradation of 4-hydroxybenzoic acid is expected to occur in aerobic and anaerobic aquatic environments based on both screening and microcosm studies (SRC). In aquifer sediment, from 34 to 70% mineralization was reported under aerobic conditions in 6 days(10). Under anaerobic conditions, 4-hydroxybenzoic acid was completely degraded in river sediments within 23 to 59 days(11).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 4-hydroxybenzoic acid, which has an extrapolated vapor pressure of 1.9X10-7 mm Hg at 25 °C(2), is expected to exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase 4-hydroxybenzoic 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 30 hours(SRC), calculated from its rate constant of 1.3X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase 4-hydroxybenzoic acid may be removed from the air by wet and dry deposition(SRC).

The rate constant for the vapor-phase reaction of 4-hydroxybenzoic acid with photochemically-produced hydroxyl radicals has been estimated as 1.3X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 30 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 4-Hydroxybenzoic acid is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(2) nor to directly photolyze due to the lack of absorption in the environmental UV spectrum (>290 nm)(3). Oxidation of 4-hydroxybenzoic acid by manganese oxides found in suspended particles in surface waters and soils in the environment is a potentially important abiotic fate(4).

An estimated BCF of 9 was calculated for 4-hydroxybenzoic acid(SRC), using a log Kow of 1.58(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC), provided the compound is not altered physically or chemically once released into the environment.

26.92 L/kg|Koc values of 142, 20, and 14 were measured according to a modified version of OECD guideline 106 for 4-hydroxybenzoic acid in a podzol (pH=2.8, C organic=4.85%, sand:silt:clay=89.2:8.2:2.6%), alfisol (pH=6.7, C organic=1.25%, sand:silt:clay=69.7:14.4:15.9%), and a sediment (pH=7.1, C organic=1.58%, sand:silt:clay=5.5:58.8:35.7%), respectively(1). According to a classification scheme(2), these Koc values suggest that 4-hydroxybenzoic acid is expected to have high to very high mobility in soil. The pKa of 4-hydroxybenzoic acid is 4.54(3), indicating that this compound will primarily exist in anion form in the environment and anions generally do not adsorb more strongly to organic carbon and clay than their neutral counterparts(4).

The Henry's Law constant for 4-hydroxybenzoic acid is estimated as 7.2X10-12 atm-cu m/mole(SRC) derived from its extrapolated vapor pressure, 1.9X10-7 mm Hg(1), and water solubility, 5000 mg/L(2). This Henry's Law constant indicates that 4-hydroxybenzoic acid is expected to be essentially nonvolatile from water surfaces(3). 4-Hydroxybenzoic acid's estimated Henry's Law constant indicates that volatilization from moist soil surfaces is not expected to occur(SRC). In addition, 4-hydroxybenzoic acid's pKa value of 4.54(4) indicates that it will exist almost entirely as an anion at pH values of 5 to 9 and therefore volatilization from water and moist soil surfaces is not expected to be an important fate process(SRC). 4-Hydroxybenzoic acid is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

GROUNDWATER: One of three groundwater samples collected in the U.K. during 1978 and 1979 contained unreported concentrations of 4-hydroxybenzoic acid(1).|SURFACE WATER: 4-Hydroxybenzoic acid dominated the other phenolic carboxylic acids present in lake water samples collected from the McMurdo Sound region of the Antarctic(1). 4-Hydroxybenzoic acid was measured in Tama river (collected November 1973) and Sumida river (collected December 1973) water samples at 10 to 90 ng/L and 1 to 9 ng/L, respectively(2). Concentrations of 4-hydroxybenzoic acid averaged 0.40 ug/L (range=0.05 to 1.7 ug/L) in surface water samples collected from the Tokyo area and the Ogasawara (Bonin) Islands(3). 4-Hydroxybenzoic acid was present in stream water collected in Sudniedersachsen, Federal Republic of Germany, at a concentration of 210 ug/L(4). 4-Hydroxybenzoic acid was not detected (detection limit not reported) in 10 surface water samples collected in the U.K. during 1977 to 1979(5).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 2722 workers (1767 of these are female) are potentially exposed to 4-hydroxybenzoic acid in the US(1). Occupational exposure to 4-hydroxybenzoic acid may occur through dermal contact with this compound at workplaces where 4-hydroxybenzoic acid is produced or used(SRC). Monitoring data indicate that the general population may be exposed to 4-hydroxybenzoic acid via inhalation of ambient air, ingestion of food, and dermal contact with this compound and other products containing 4-hydroxybenzoic acid(SRC).

...Groups of 4-8 rabbits were given 4-hydroxybenzoic acid at a dose of 100, 250, 500, 1000, or 1500 mg/kg bw by gavage every 3-7 days. Urine was collected continuously and analysed for metabolites. The total urinary recovery of the test material ranged from 84% to 104%. Glucuronic acid and sulfate conjugates were also detected in the urine, at 10-35% and 4-7%, respectively. The concentrations of all the metabolites returned to background values within 24 hr after dosing.

In rabbits, 96% of a single oral dose of 400 mg/kg bw 4-hydroxybenzaldehyde was excreted in the urine within 24 hr as 4-hydroxybenzoic acid and its glycine, glucuronic acid, and sulfate conjugates.|...Metabolism in the rat of p-hydroxybenzoic acid and its methyl, ethyl and propyl esters resulted in the appearance in the urine first of free p-hydroxybenzoic acid, followed by the glucuronide and p-hydroxyhippuric acid, the concentration of which increased as that of the free p-hydroxybenzoic acid /decreased/.

4-hydroxybenzoate

All other basic organic chemical manufacturing|Benzoic acid, 4-hydroxy-: ACTIVE

Method: AOAC 990.25; Procedure: liquid chromatographic method; Analyte: p-hydroxybenzoic acid; Matrix: vanilla extract and artificial vanilla flavor; Detection Level: not provided.[|Methods for analyzing carboxylic acids and phenols are also applicable to hydroxycarboxylic acids. In practice, alkalimetric titration (in special cases, potentiometric titration) is used. With potentiometric determination of equivalence point, the hydroxyl group can also be determined. Trace analyses are carried out by colorimetric methods with iron(III)chloride. Thin-layer chromatography is a suitable method for checking purity. ... For quantitative analysis, HPLC methods are suitable. Alternatively, the components can be derivatized and capillary gas chromatographic methods used to separate them.

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