Pentanoic Acid

H314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H412: Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P260, P264, P273, P280, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P321, P363, P405, and P501 (click each P-code to see the statement)

H302 (24.1%): Harmful if swallowed [Warning Acute toxicity, oral]

H314 (100%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H318 (31.7%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

H412 (97.3%): Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P260, P264, P264+P265, P270, P273, P280, P301+P317, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P321, P330, P363, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 2426 reports by companies from 13 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

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.

H227: Combustible liquid [Warning Flammable liquids]

H302: Harmful if swallowed [Warning Acute toxicity, oral]

H311: Toxic in contact with skin [Danger Acute toxicity, dermal]

H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]

H332: Harmful if inhaled [Warning Acute toxicity, inhalation]

P210, P260, P261, P262, P264, P264+P265, P270, P271, P280, P301+P317, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P321, P330, P361+P364, P363, P370+P378, P403, P405, and P501 (click each P-code to see the statement)

Fresh air, rest. Refer for medical attention.

Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention .

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Give one or two glasses of water to drink. Do NOT induce vomiting. Refer for medical attention .

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: DO NOT INDUCE VOMITING. Corrosive chemicals will destroy the membranes of the mouth, throat, and esophagus and, in addition, have a high risk of being aspirated into the victim's lungs during vomiting which increases the medical problems. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. IMMEDIATELY transport the victim to a hospital. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. Transport the victim IMMEDIATELY to a hospital. (NTP, 1992)

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:

SMALL FIRE: Dry chemical, CO2 or water spray.

LARGE FIRE: Dry chemical, CO2, alcohol-resistant foam or water spray. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. 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. (ERG, 2024)

Use water spray, powder, foam, carbon dioxide.

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

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)

Do NOT let this chemical enter the environment. Collect leaking liquid in covered containers. Wash away remainder with plenty of water.

Collect leaking liquid in covered containers. Wash away spilled liquid with plenty of water. Do NOT let this chemical enter the environment.

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.

Strict precautions are necessary in handling ... any skin or eye splashes irrigated with copious amounts of water. /Saturated monocarboxylic acids/

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2024)

Separated from strong bases.

15 [mg/m3]

24 [mg/m3]

140 [mg/m3]

No indication can be given about the rate at which a harmful concentration of this substance in the air is reached on evaporation at 20 °C.

The substance is corrosive to the eyes, skin and respiratory tract. Corrosive on ingestion.

Full impervious protective clothing, including boots and gloves. Where splashing is possible wear full face shield or chemical safety goggles. Do not wear contact lenses when working with this material. Use approved respirator to protect against vapors. (USCG, 1999)

... Suitable protective equipment should be available ... /Saturated monocarboxylic acids/

NO open flames. Above 86 °C use a closed system and ventilation.

AVOID ALL CONTACT! IN ALL CASES CONSULT A DOCTOR!

Use ventilation, local exhaust or breathing protection.

Protective gloves. Protective clothing.

Wear face shield.

Do not eat, drink, or smoke during work.

Pentanoic acid appears as a colorless liquid with a penetrating unpleasant odor. Density 0.94 g / cm3. Freezing point -93.2 °F (-34 °C). Boiling point 365.7 °F (185.4 °C). Flash point 192 °F (88.9 °C). Corrosive to metals and tissue.

Liquid; Other Solid; Liquid; CBI

Colorless liquid with an unpleasant odor; [Merck Index]

COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR.

colourless to pale yellow mobile liquid/unpleasant, penetrating rancid odour

Colorless liquid

UNPLEASANT ODOR, SIMILAR TO BUTYRIC ACID

Unpleasant odor

Penetrating odor

Unpleasant flavor, similar to butyric acid

FRUITY TASTE

Penetrating taste

365 °F at 760 mmHg (NTP, 1992)

186-187 °C

186.4 °C @760 [mm Hg]

-30.1 °F (NTP, 1992)

-34.5 °C

192 °F (NTP, 1992)

205 °F (96 °C) (Open cup)

86 °C c.c.

10 to 50 mg/mL at 72 °F (NTP, 1992)

Freely soluble in alcohol, ether

Soluble in oxygenated solvents.

Slightly soluble in carbon tetrachloride

In water, 2.4X10+4 mg/L at 25 °C

24.0 mg/mL

Solubility in water, g/100ml: 2.4

miscible with alcohol, ether, 1 ml in 40 ml water

(in ethanol)

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

0.939 at 20 °C/4 °C

Relative density (water = 1): 0.94

0.935-0.940

0.940 @ 20°C

3.52 (NTP, 1992) - Heavier than air; will sink (Relative to Air)

3.5 (Air = 1)

Relative vapor density (air = 1): 3.52

1 mmHg at 108 °F ; 40 mmHg at 226.0 °F; 760 mmHg at 363.9 °F (NTP, 1992)

0.19 [mmHg]

Vapor pressure, kPa at 20 °C: 0.02

Water soluble.

Acids, Carboxylic

PENTANOIC ACID is a carboxylic acid. Exothermically neutralizes bases, both organic and inorganic, producing water and a salt. Can react with active metals to form gaseous hydrogen and a metal salt. Reacts with cyanide salts to generate gaseous hydrogen cyanide. Flammable and/or toxic gases and heat are generated by reaction with diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides. Reacts with sulfites, nitrites, thiosulfates and dithionites to generate flammable and/or toxic gases and heat. Reacts with carbonates and bicarbonates to generate a harmless gas (carbon dioxide) but still heat. Can be oxidized by strong oxidizing agents and reduced by strong reducing agents. These reactions generate heat. May initiate polymerization reactions. May catalyze (increase the rate of) chemical reactions.

The substance can be absorbed into the body by inhalation and by ingestion.

Burning sensation. Cough. Sore throat.

Redness. Pain. Skin burns.

Redness. Pain. Severe burns.

Burning sensation. Abdominal pain. Shock or collapse.

Dermatotoxin - Skin burns.

Toxic Pneumonitis - Inflammation of the lungs induced by inhalation of metal fumes or toxic gases and vapors.

LC50 (mice) = 2,050 mg/m3/4h

LD50 Mouse iv 1290 mg/kg

LD50 Mouse sc 3590 mg/kg

LC50 Mouse inhalation 4100 mg/cu m/2 hr

LD50 Mouse ip 3590 mg/kg

For more Non-Human Toxicity Values (Complete) data for n-PENTANOIC ACID (9 total), please visit the HSDB record page.

/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist respirations 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 ... . 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. Activated charcoal is not effective ... . Do not attempt to neutralize because of exothermic reaction. Cover skin burns with dry, sterile dressings after decontamination ... . /Organic acids 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. 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 ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as 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. Consider vasopressors if patient is hypotensive with a normal fluid volume. Watch for signs of fluid overload ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Organic acids and related compounds/

/ALTERNATIVE and IN VITRO TESTS/ An increase in the production of interferon was observed in Namalwa cells cultured for 24 hours or more in the presence of 5 mmol valeric acid and then induced with sendai virus. All substances which enhanced interferon production blocked thymidine incorporation into Namalwa cell DNA at concentrations equal to those effective in interferon stimulation. Apparently, these inducers of friend cell erythropoietic differentiation are also inducers of interferon production.

/LABORATORY ANIMALS: Acute Exposure/ No mortality occurred when rats were exposed for 8 hours to air saturated with valeric acid vapor.

/LABORATORY ANIMALS: Acute Exposure/ ... Intravenous administration of valeric acid ... up to 1 g/kg in cats and 0.5 g/kg in dogs causes somnolence followed by diuresis, vomiting, and defecation, with rapid recovery. /10% aqueous solutions/

/LABORATORY ANIMALS: Acute Exposure/ In contrast to butyric acid, oral administration of valeric acid did not result in coma in rabbits.

/LABORATORY ANIMALS: Acute Exposure/ ... Valeric acid is a strong skin irritant in the undiluted form. Using mixed isomers of valeric acid (unspecified composition) ... some tissue necrosis /was demonstrated/ with 10 mg of material in a 24 hr open, rabbit skin irritation assay.

For more Non-Human Toxicity Excerpts (Complete) data for n-PENTANOIC ACID (14 total), please visit the HSDB record page.

Pentanoic acid (CAS # 109-52-4) was evaluated for subchronic dermal toxicity in New Zealand White rabbits exposed to 0 or 500 mg/kg (in mineral oil solution) non-occluded applications upon abraded skin (3/5 males, 2/5 females) or shaved intact skin (3/5 females, 2/5 males) on 5 consecutive days/week for 2 weeks (10 total applications). One female died on the 7th day of treatment, exhibiting hypopnea, hypoactivity, diminished food consumption, and red anal discharge prior to death. Pharmacotoxic signs noted among survivors included diminished food consumption, nasal discharge, and vocalization upon handling. Without exception, the animals showed transient weight loss in the second week of treatment and worsening signs of dermal irritation including severe erythema, moderate to severe edema, necrosis with eschar, atonia, desquamation, and dermal fissuring. Eschar tissue exfoliated during the second week of treatment and all animals were free of any signs of toxicity by end of study. Upon necropsy, no increased incidence of gross pathological changes relative to controls were identified. Micropathological evaluation of the collective irritative eschar found epidermal hyperplasia, and hyperkeratosis, as well as diffuse and perifollicular dermal inflammation. Rabbits surviving 2-week post-treatment recovery demonstrated some persisting epidermal hyperplasia and hyperkeratosis, but were otherwise free of irritative signs. No significant difference was noted in irritative responses on abraded or intact skin.

n-Pentanoic acid (CAS # 109-52-4) was evaluated for carcinogenic potential in adermal study of C3H/HeJ mice (50/group) administered interscapular applications of 50 mg/kg undiluted test substance twice weekly for 80 weeks. Severe dermal and systemic toxicity noted upon a 4th application was in excess of that observed during an initial pilot study and necessitated amendment of treatment and dermal doses were reduced to 25 mg/kg for the remainder of the study. Despite this change in protocol, decreased survival (10%) among the treated animals relative to controls (no treatment) lowered a final effective number of mice living long enough to develop treatment-related tumors. Depressed bodyweight gains (17%), and epilation, ulceration, and crustiness of the skin at treatment sites were also exhibited among treated mice. The condition of the treated skin further complicated gross recognition of dermal neoplasms. Seven of 12 treated animals demonstrating benign and/or malignant tumors were identified upon microscopic examination of treated dermis, while 5/12 were identified at twice daily examinations during the in-life portion of study. Observed neoplasms in treated mice were characterized as squamous cell carcinomas of the skin (4/4 mice), fibrosarcomas (6/6 mice), fibromas (5/3 mice) and a solitary incidence of keratoacanthoma, relative to one malignant squamous cell carcinoma of the skin noted in a control animal. An average latent period for 5/12 neoplasms observed in living mice was 61.8 weeks. Due to the profound systemic toxicity, 19/50 treated mice also underwent histologic evaluation of all major visceral organs and the brain. No additional gross pathology or microscopic findings in excess of controls was documented.

n-Valeric acid (CAS # 109-52-4) was evaluated for genotoxic effects in the Chinese Hamster Ovary (CHO)/HGPRT gene mutation test. Based on preliminary cytotoxicity tests, cultures of chinese hamster ovary cells incorporating metabolic activation with Aroclor 1254-induced S-9 rat liver homogenate were exposed for 5 hours to concentrations of 0.2 to 1.6 mg/ml, while non-activated cultures were exposed to concentrations of 0.6 to 1.4 mg/ml. In both activated and non-activated cultures, doses of 1.0 mg/ml and above were associated with excessive cytotoxicity, however throughout the range of exposure concentrations no dose-related mutagenicity was established relative to solvent control (ethanol). Investigators reported a steep cytotoxicity curve for the test substance and CHO cells at 1.0 - 1.3 mg/ml. A numerical increase in mutagenicity was seen in association with 0.6 mg/ml exposures in the non-activated cultures, and background mutagenicity in control cultures with metabolic activation were found excessively high relative to historical controls. These findings prompted a second investigation of test concentrations centered about 0.6 mg/ml in metabolically non-activated cultures. In the CHL/HGPRT gene mutation test with concentrations of 0.20 to 0.60 mg/ml (-S9) and 0.60 to 1.20 (+S9), no reproducible or dose-related mutagenic effects were noted in association with any concentration in either culture preparation.

n-Valeric acid (CAS # 109-52-4) was evaluated for genotoxic effects in the Chinese Hamster Ovary (CHO)/HGPRT in vitro chromosome aberration test. Based on preliminary cytotoxicity tests and equivocal results in an initial genotoxicity test, ovary cell cultures incorporating metabolic activation with Aroclor 1254-induced S-9 rat liver homogenate were exposed for 8 or 12 hours to concentrations of 0.6 to 1.2 mg/ml, while non-activated cultures were exposed to concentrations of 0.07 to 0.2 mg/ml. Cytotoxicity testing established that, in activated and non-activated cultures, 1.2 and 0.3 mg/ml were associated with 66.7% and 55.6% reduction in the respective mitotic indices. In genotoxicity testing, incidence of chromosome aberrations were determined from 100-cell samples of those cultures exposed to the highest concentrations not producing excessive mitotic inhibition. S9-activated cultures exposed to 1.1 and 1.2 mg/ml sampled at both 8 hours and 12 hours demonstrated significant (p < 0.05 and 0.01, respectively) dose-related clastogenic effects relative to control (ethanol solvent), as did the 0.2 mg/ml exposed non-activated cultures (p < 0.05) sampled at 12 hours. Chromatid breaks characterized the majority of aberrations associated with the test substance.

Valeric acid (C-180; 109-52-4) was evaluated for developmental effects in 22 female Crl:COBS, CD(SD)BR rats administered 750 mg/kg of the test substance by gavage on days 6 through 15 of gestation. A control group received corn oil. Maternal animals showed an increased incidence of clinical observations (specific signs not reported). Offspring showed an increased incidence of delayed ossification of several bone structures.

LC50 Daphnia magna (Water flea) 45 mg/L/48 hr; static /formulated product/

LC50 Lepomis macrochirus (Bluegill) 5,000 mg/L/24 hr /Conditions of bioassay not specified in source examined/ /Na salt/

LC50 Pimephales promelas (Fathead minnow) >100 mg/L/1 hr, static

LC50 Pimephales promelas (Fathead minnow) >100 mg/L/24 hr, static

For more Ecotoxicity Values (Complete) data for n-PENTANOIC ACID (8 total), please visit the HSDB record page.

The substance is harmful to aquatic organisms.

n-Pentanoic acid's production and use as chemical intermediate and sugarcane ripening agent may result in its release to the environment through various waste streams. n-Pentanoic acid is found in the essential oil of Boronia anemonifolia, pineapple fruits, and dalieb fruit pulp. If released to air, an estimated vapor pressure of 1.96X10-1 mm Hg at 25 °C indicates n-pentanoic acid will exist solely as a vapor in the atmosphere. Vapor-phase n-pentanoic acid 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 4.11X10-12 cu cm/molec-sec. If released to soil, pentanoic acid is expected to have high mobility based upon an estimated Koc of 140. The pKa of n-pentanoic acid is 4.84, indicating that this compound will partially exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts. Volatilization from moist soil surfaces is not expected to be an important fate process based upon a Henry's Law constant of 4.72X10-7 atm-cu m/mole. n-Pentanoic acid is not expected to volatilize from dry soil surfaces based upon its vapor pressure. n-Pentanoic acid is expected to be readily biodegradable in most environmental conditions based on the results of a sewage sludge inoculum test where n-pentanoic acid reached 68% of its theoretical BOD in 5 days. If released into water, n-pentanoic acid is not expected to adsorb to suspended solids and sediment based upon the Koc. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's Henry's Law constant. An estimated BCF of 7 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions. Occupational exposure to n-pentanoic acid may occur through dermal contact with this compound at workplaces where n-pentanoic acid is produced or used. Monitoring data indicate that the general population may be exposed to pentanoic acid via inhalation of ambient air, ingestion of food and drinking water, and dermal contact with this compound and other products containing pentanoic acid. n-Pentanoic acid was widely detected in a variety of effluent sources ranging from wastewater from industrial areas and radioactive material disposal sites and in landfill leachates. (SRC)

THE ACID IS NOT COMMON IN NATURE. REPORTED (AS THE CORRESPONDING ESTER) FOUND IN ESSENTIAL OIL OF BORONIA ANEMONIFOLIA, IN PINEAPPLE FRUITS, & IN OTHER PLANTS; ALSO IDENTIFIED AS ACID OR THE CORRESPONDING ESTER IN THE ESSENTIAL OIL OF LEMON PETITGRAIN.

n-Pentanoic acid was identified as a volatile fatty acid occurring in dalieb fruit pulp at a concentration of 5 mg/kg pulp(1).

THIS REPORT GIVES RESULTS OF INVESTIGATIONS OF ADIPIC ACID DEGRADATION TO ACCOUNT FOR LOSSES OBSERVED DURING EARLIER STUDIES WHERE IT WAS USED AS AN ADDITIVE TO IMPROVE SO2 SCRUBBER PERFORMANCE. LABORATORY EXPERIMENTS IDENTIFIED ONE OF THE MAJOR SPECIES AS VALERIC ACID.

n-Pentanoic acid's production and use as an intermediate for flavors and perfumes, ester-type lubricants, plasticizers, pharmaceuticals, vinyl stabilizers and use as a sugarcane ripening 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 140(SRC), determined from a log Kow of 1.39(2) and a regression-derived equation(3), indicates that n-pentanoic acid is expected to have high mobility in soil(SRC). The pKa of n-pentanoic acid is 4.84(4), indicating that this compound will partially exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(5). Volatilization of n-pentanoic acid from moist soil surfaces is not expected to be an important fate process(SRC) given a Henry's Law constant of 4.72X10-7 atm-cu m/mole(6). n-Pentanoic acid is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.96X10-1 mm Hg(7). n-Pentanoic acid is expected to be readily biodegradable in most environmental conditions based on several biodegradation tests where n-pentanoic acid reached 43%(8) to 68%(9) of its theoretical BODs in sewage inoculum after 5 days.

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 140(SRC), determined from a log Kow of 1.39(2) and a regression-derived equation(3), indicates that n-pentanoic acid is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon a Henry's Law constant of 4.72X10-7 atm-cu m/mole(4). According to a classification scheme(5), an estimated BCF of 7(SRC), from its log Kow(2) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low(SRC). n-Pentanoic acid is expected to be readily biodegradable in most environmental conditions based on several biodegradation tests where n-pentanoic acid reached 43%(7) to 68%(8) of its theoretical BODs in sewage inoculum after 5 days.

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), n-pentanoic acid, which has an estimated vapor pressure of 1.96X10-1 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase n-pentanoic 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 3.9 days(SRC), calculated from its rate constant of 4.11X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3).

LC50 Daphnia magna (Water flea) 45 mg/L/48 hr; static /formulated product/

LC50 Lepomis macrochirus (Bluegill) 5,000 mg/L/24 hr /Conditions of bioassay not specified in source examined/ /Na salt/

LC50 Pimephales promelas (Fathead minnow) >100 mg/L/1 hr, static

LC50 Pimephales promelas (Fathead minnow) >100 mg/L/24 hr, static

For more Ecotoxicity Values (Complete) data for n-PENTANOIC ACID (8 total), please visit the HSDB record page.

The substance is harmful to aquatic organisms.

n-Pentanoic acid's production and use as chemical intermediate and sugarcane ripening agent may result in its release to the environment through various waste streams. n-Pentanoic acid is found in the essential oil of Boronia anemonifolia, pineapple fruits, and dalieb fruit pulp. If released to air, an estimated vapor pressure of 1.96X10-1 mm Hg at 25 °C indicates n-pentanoic acid will exist solely as a vapor in the atmosphere. Vapor-phase n-pentanoic acid 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 4.11X10-12 cu cm/molec-sec. If released to soil, pentanoic acid is expected to have high mobility based upon an estimated Koc of 140. The pKa of n-pentanoic acid is 4.84, indicating that this compound will partially exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts. Volatilization from moist soil surfaces is not expected to be an important fate process based upon a Henry's Law constant of 4.72X10-7 atm-cu m/mole. n-Pentanoic acid is not expected to volatilize from dry soil surfaces based upon its vapor pressure. n-Pentanoic acid is expected to be readily biodegradable in most environmental conditions based on the results of a sewage sludge inoculum test where n-pentanoic acid reached 68% of its theoretical BOD in 5 days. If released into water, n-pentanoic acid is not expected to adsorb to suspended solids and sediment based upon the Koc. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's Henry's Law constant. An estimated BCF of 7 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions. Occupational exposure to n-pentanoic acid may occur through dermal contact with this compound at workplaces where n-pentanoic acid is produced or used. Monitoring data indicate that the general population may be exposed to pentanoic acid via inhalation of ambient air, ingestion of food and drinking water, and dermal contact with this compound and other products containing pentanoic acid. n-Pentanoic acid was widely detected in a variety of effluent sources ranging from wastewater from industrial areas and radioactive material disposal sites and in landfill leachates. (SRC)

THE ACID IS NOT COMMON IN NATURE. REPORTED (AS THE CORRESPONDING ESTER) FOUND IN ESSENTIAL OIL OF BORONIA ANEMONIFOLIA, IN PINEAPPLE FRUITS, & IN OTHER PLANTS; ALSO IDENTIFIED AS ACID OR THE CORRESPONDING ESTER IN THE ESSENTIAL OIL OF LEMON PETITGRAIN.

n-Pentanoic acid was identified as a volatile fatty acid occurring in dalieb fruit pulp at a concentration of 5 mg/kg pulp(1).

THIS REPORT GIVES RESULTS OF INVESTIGATIONS OF ADIPIC ACID DEGRADATION TO ACCOUNT FOR LOSSES OBSERVED DURING EARLIER STUDIES WHERE IT WAS USED AS AN ADDITIVE TO IMPROVE SO2 SCRUBBER PERFORMANCE. LABORATORY EXPERIMENTS IDENTIFIED ONE OF THE MAJOR SPECIES AS VALERIC ACID.

n-Pentanoic acid's production and use as an intermediate for flavors and perfumes, ester-type lubricants, plasticizers, pharmaceuticals, vinyl stabilizers and use as a sugarcane ripening 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 140(SRC), determined from a log Kow of 1.39(2) and a regression-derived equation(3), indicates that n-pentanoic acid is expected to have high mobility in soil(SRC). The pKa of n-pentanoic acid is 4.84(4), indicating that this compound will partially exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(5). Volatilization of n-pentanoic acid from moist soil surfaces is not expected to be an important fate process(SRC) given a Henry's Law constant of 4.72X10-7 atm-cu m/mole(6). n-Pentanoic acid is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.96X10-1 mm Hg(7). n-Pentanoic acid is expected to be readily biodegradable in most environmental conditions based on several biodegradation tests where n-pentanoic acid reached 43%(8) to 68%(9) of its theoretical BODs in sewage inoculum after 5 days.

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 140(SRC), determined from a log Kow of 1.39(2) and a regression-derived equation(3), indicates that n-pentanoic acid is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon a Henry's Law constant of 4.72X10-7 atm-cu m/mole(4). According to a classification scheme(5), an estimated BCF of 7(SRC), from its log Kow(2) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low(SRC). n-Pentanoic acid is expected to be readily biodegradable in most environmental conditions based on several biodegradation tests where n-pentanoic acid reached 43%(7) to 68%(8) of its theoretical BODs in sewage inoculum after 5 days.

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), n-pentanoic acid, which has an estimated vapor pressure of 1.96X10-1 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase n-pentanoic 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 3.9 days(SRC), calculated from its rate constant of 4.11X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3).

AEROBIC: n-Pentanoic acid reached 50, 68, 82, and 74% of its theoretical BOD on days 2, 5, 10, and 30, respectively, using a domestic sewage inoculum and a pentanoic acid concentration of 3.4 ppm(1). After 5 days incubation, n-pentanoic acid reached 43% of its theoretical BOD using a sewage inoculum(2). A 99 and 98% BOD reduction was observed for n-pentanoic acid after 16 and 23 days, respectively, using an activated sludge system operated under semi-continuous conditions(3). n-Pentanoic acid reached 52% of its theoretical BOD after 5 days using a sewage inoculum(4). n-Pentanoic acid, present at an initial concentration of 500 ppm, was readily degraded, 22.9 to 44.7% of theoretical BOD after 72 hours, by activated sludge obtained from three different treatment plants(5). In screening tests, n-pentanoic acid, present at a concentration of 3 ppm, reached 74.9 and 62.0% of its theoretical BOD in 5 days using the standard dilution method and seawater dilution method, respectively(6). After a lag period of 5 hours, n-pentanoic acid, present at a concentration of 100 ppm, was degraded at a rate of 0.07 to 0.072 1/hour using an activated sludge inoculum(7). A total organic carbon removal ratio of 87% was observed for n-pentanoic acid using a non-acclimated activated sludge and an initial n-pentanoic acid concentration of 100 mg total organic carbon/L(8).

ANAEROBIC: After a lag period of 3 days, n-pentanoic acid was metabolized, at a rate of 72 mg/L day, by anaerobic bacteria acclimated to acetate culture(1). Pentanoic acid, present at a concn of 4.6 mg/L was degraded 100% after 30 days by a mixed culture of anaerobic bacteria obtained from trench leachate of a low-level radioactive waste disposal site in Maxey Flats, KY(2). A 27% increase in concn was observed for n-pentanoic acid, present at an initial concn of 5.5 mg/L, in a similar test with anaerobic bacteria obtained from different trench leachate(2). An initial n-pentanoic acid concn of 30 mg carbon/L was anaerobically biodegraded 95% after 7 days incubation in synthetic sewage(3). Pentanoic acid was labeled "readily biodegradable" as the result of an anaerobic sewage sludge test that measured net gas production from 10 mL of laboratory prepared sludge suspension, 90 mL of inorganic medium, and 10 mgC of n-pentanoic acid(4).

The rate constant for the vapor-phase reaction of n-pentanoic acid with photochemically-produced hydroxyl radicals has been estimated as 4.11X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 3.9 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). n-Pentanoic acid is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2).

An estimated BCF of 7 was calculated for n-pentanoic acid(SRC), using a log Kow of 1.39(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).

The Koc of n-pentanoic acid is estimated as 140(SRC), using a log Kow of 1.39(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that n-pentanoic acid is expected to have high mobility in soil. In aqueous solution, n-pentanoic acid adsorbed 15.4 and 37.9% onto the clay minerals kaolinite and montmorillonite, respectively, after 144 hours at 22 °C(4). The pKa of n-pentanoic acid is 4.84(5), indicating that this compound will partially exist in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(6).

The Henry's Law constant for n-pentanoic acid is 4.72X10-7 atm-cu m/mole(1). This Henry's Law constant indicates that n-pentanoic acid is expected to be essentially nonvolatile from water surfaces(2). Volatilization of the ionized form from water surfaces is not expected to be an important fate process(SRC). Pentanoic acid is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.96X10-1 mm Hg(3).

DRINKING WATER: n-Pentanoic acid was quantitatively detected in drinking water in Cincinnati, OH in Oct 1978 and Jan 1980, Miami, FL in Feb 1976, New Orleans, LA in Jan 1976, Philadelphia, PA in Feb 1976, Ottumwa, IA in Sept 1976, and in Seattle, WA in Nov 1976(1). n-Pentanoic acid was identified as a non-halogenated disinfection byproduct in ozonated drinking water at a pilot plant in Jefferson Parish, LA from four rounds of sampling taken between January, 1994 and September, 1996(3).

SURFACE WATER: n-Pentanoic acid was detected in the Ohio and Little Miami Rivers, downstream from an unspecified municipality, at concns ranging from 0.1 ug/L in the Ohio River to 0.2 ug/L in the Little Miami River(1). n-Pentanoic acid was detected in the Ohio and Little Miami Rivers, upstream from an unspecified municipality, at concns ranging from 0.1 ug/L in the Little Miami River to 0.3 ug/L in the Ohio River(1). n-Pentanoic acid was identified in Tanners Creek at a concn of 0.3 ug/L(1).

RAIN/SNOW: n-Pentanoic acid was detected in rainwater samples collected in a suburb of Hannover, Germany at an unspecified concn(1). n-Pentanoic acid was detected in rain and snow samples collected from southern CA at concns ranging from 0.006 to 0.20 uM(2).

n-Pentanoic acid was identified in trench leachate from low-level radioactive waste disposal sites in Maxey Flats, KY and West Valley, NY at an average concn of 3.8 and 47 mg/L, respectively(1). n-Pentanoic acid was detected in raw and processed wastewater from the Lurgi-Process Plant in Sasolburg, South Africa at concns of 12 and 7 mg/L, respectively(2). n-Pentanoic acid was identified as a volatile component of kitchen waste exudate(3). n-Pentanoic acid was identified in the final effluent from the Los Angeles County wastewater treatment plant between Nov 1980 and August 1981 at a concn of 50 ug/L(4). Groundwater samples collected near an area known to be contaminated by wood-preserving chemicals in Pensacola, FL contained n-pentanoic acid at concns of 6.55, 1.53, and 0.51 mg/L 6.1, 3.3, and 5.8 m below the surface, respectively(5). n-Pentanoic acid was detected in groundwater from a landfill well near Norman, OK at an estimated concn of 1.1 ug/L(6). n-Pentanoic acid was detected in the acidic fraction of oil shale retort water at a concn of 210 mg/L(7). Groundwater samples collected 15.5 feet below the land surface near an area contaminated with gasoline contained n-pentanoic acid at a concn of 2 ug/L(8).

n-Pentanoic acid was detected in the leachate of a sanitary landfill located in Barcelona, Spain at an unreported concn(1). n-Pentanoic acid was identified in the effluent of a publicly owned treatment works facility located in an industrial area of NJ at an estimated concn of 8 ppb(2). n-Pentanoic acid was detected in: product water samples from an in situ coal gasification site in Hanna, WY at a concn of 1060 ppm; retort water from in situ oil shale processing in Rock Springs, WY at a concn of 5 ppm; and boiler blowdown water from in situ shale oil processing in DeBeque, CO at a concn of 4 ppm(3). Pentanoic acid was detected in condensate retort water and process retort water from the Occidental Oil Shale, Inc facility in Logan Wash, CO at concns of 0.3 and 110 mg/L, respectively(4). n-Pentanoic acid was identified as a byproduct of chlorine dioxide disinfection of drinking water at a pilot plant in Evansville, IN(5). n-Pentanoic acid was detected in primary and secondary effluents from four sewage treatment plants at concns ranging from 3.7 to 379 ug/L and 0.6 to 40 ug/L, respectively(6).

ONE OF VOLATILE ACIDS IDENTIFIED IN THE RAW SEWAGE IN HAIFA, ISRAEL WAS VALERIC ACID.

n-Pentanoic acid was detected in groundwater down-gradient from a crude oil spill in Bemidiji, MN from 1986-1990 at concentrations ranging from 0.009 to 0.326 uM(1). Samples were taken from distances ranging from 0-90 m downgradient from the spill(1). n-Pentanoic acid was extracted from oil-field wastewater samples from an oil processing facility located in California in concentrations ranging from 0.0009 mg/L to 1.37 mg/L(2).

SEDIMENT: n-Pentanoic acid was detected in sediment samples from Loch Eil, Scotland(1). The concn in sediment pore water from Station E-24 ranged from 9.3 to 160 ug/g dry weight at 9 to 12 cm and 0 to 3 cm, respectively(1); sediment pore water from Station E-70, located about 2 km from the effluent outfall of a pulp and paper mill, contained 1.3 to 24 ug/g dry weight pentanoic acid at 9 to 12 cm and 0 to 3 cm, respectively(1).

URBAN/SUBURBAN: n-Pentanoic acid was detected in the daytime air of Fukaya, Takasaki, and Karuizawa, Japan at 0.01, 0.02, and 0.01 ppb, respectively, in 1986(1).

SOURCE DOMINATED: n-Pentanoic acid has been reported as a component of diesel exhaust(1). On Sept 8-9, 1993 n-pentanoic acid was detected in the ambient air during a photochemical smog episode in Los Angeles, CA at an average concn of 0.26 ug/cu m for 6 samples with a high and low concn of 0.00 ug/cu m and 0.34 ug/cu m(2).

n-Pentanoic acid has been identified as a volatile component of roasted filberts(1), Parma ham(2), fried chicken flavor(3), bacon flavor(4), baked potato flavor(5), and raw beef(6). n-Pentanoic acid was identified as a volatile fatty acid occurring in dalieb fruit pulp at a concn of 5 mg/kg pulp(7). Pentanoic acid has been identified as a volatile flavor component of mutton, chicken, beef, and pork(8). n-Pentanoic acid was identified as a volatile component of microwave popcorn at a concn of 130 ug/kg(9). n-Pentanoic acid was identified as a volatile component of two commercial rice cakes at concns of 210 ppb and 270 ppb(10).

n-Pentanoic acid was detected in rotten mussels obtained from the Oarai Coast in Ibaraki, Japan at a concn of 0.69 ug/g wet weight(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 4,509 workers (780 of these are female) are potentially exposed to n-pentanoic acid in the US(1). Occupational exposure to n-pentanoic acid may occur through inhalation and dermal contact with this compound at workplaces where n-pentanoic acid is produced or used(SRC). The general population may be exposed to n-pentanoic acid via inhalation of ambient air, and ingestion of contaminated food and drinking water(SRC).

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.

Corrosive

Symbol: C; R: 34-52/53; S: (1/2)-26-36-45-61

UN Hazard Class: 8