hexanoic acid

This chemical does not meet GHS hazard criteria for < 0.1% (2 of 2136) of reports.

H311 (17.1%): Toxic in contact with skin [Danger Acute toxicity, dermal]

H314 (> 99.9%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H318 (82.1%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

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

Aggregated GHS information provided per 2136 reports by companies from 34 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Reported as not meeting GHS hazard criteria per 2 of 2136 reports by companies.

There are 32 notifications provided by 2134 of 2136 reports by companies with hazard statement code(s).

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

Not Classified

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

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

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

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

P260, P261, P262, P264, P264+P265, P270, P271, P280, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P321, P361+P364, P363, 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. Do NOT induce vomiting. Give one or two glasses of water to drink. Rest.

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)

General First Aid:

· Call 911 or emergency medical service.

· Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.

· Move victim to fresh air if it can be done safely.

· Administer oxygen if breathing is difficult.

· If victim is not breathing:

-- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance.

-- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).

-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.

· Remove and isolate contaminated clothing and shoes.

· For minor skin contact, avoid spreading material on unaffected skin.

· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.

· For severe burns, immediate medical attention is required.

· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.

· Keep victim calm and warm.

· Keep victim under observation.

· For further assistance, contact your local Poison Control Center.

· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.

Specific First Aid:

· For corrosives, in case of contact, immediately flush skin or eyes with running water for at least 30 minutes. Additional flushing may be required.

· Removal of solidified molten material from skin requires medical assistance.

In Canada, an Emergency Response Assistance Plan (ERAP) may be required for this product. Please consult the shipping paper and/or the "ERAP" section.

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 powder, AFFF, foam, carbon dioxide.

To fight fire use, CO2, dry chemical, fog, mist.

If material on fire or involved in fire: Use water in flooding quantities as fog. Solid streams of water may be ineffective. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use "alcohol" foam, carbon dioxide or dry chemical. Use water spray to knock-down vapors.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· Keep unauthorized personnel away.

· Stay upwind, uphill and/or upstream.

· Ventilate closed spaces before entering, but only if properly trained and equipped.

· 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.

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)

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.

· For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.

· For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind direction, as necessary.

· 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.

Do NOT let this chemical enter the environment. Collect leaking and spilled liquid in sealable containers as far as possible. Wash away remainder with plenty of water.

Collect leaking liquid in sealable containers. Wash away spilled liquid with plenty of water. Do NOT wash away into sewer.

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.

The following wastewater treatment technology has been investigated for caproic acid: Concentration process: Activated carbon.

The following wastewater treatment technology has been investigated for caproic acid: Concentration process: Resin adsorption.

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Use water spray to knock-down vapors. Neutralize spilled material with crushed limestone, soda ash, or lime.

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

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 oxidants, strong bases and food and feedstuffs.

Separated from strong oxidants, strong bases, food and feedstuffs.

· Wear positive pressure self-contained breathing apparatus (SCBA).

· Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE.

· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

15 [mg/m3]

24 [mg/m3]

140 [mg/m3]

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.

A harmful contamination of the air will not or will only very slowly be reached on evaporation of this substance at 20 °C.

The substance is irritating to the eyes, skin and respiratory tract. If this liquid is swallowed, aspiration into the lungs may result in chemical pneumonitis.

Respirator, chemical safety goggles, rubber boots and heavy rubber gloves. (USCG, 1999)

Strict precautions are necessary in handling, suitable protective equipment should be available. /Saturated monocarboxylic acids/

NO open flames. NO contact with strong oxidizing agents.

PREVENT GENERATION OF MISTS!

Use ventilation, local exhaust or breathing protection.

Protective gloves. Protective clothing.

Wear safety goggles or eye protection in combination with breathing protection.

Do not eat, drink, or smoke during work.

Caproic acid appears as a white crystalline solid or colorless to light yellow solution with an unpleasant odor. Insoluble to slightly soluble in water and less dense than water. Contact may severely irritate skin, eyes and mucous membranes. May be toxic by ingestion, inhalation and skin absorption. Used to make perfumes.

Liquid; Liquid; Other Solid

Colorless or slightly yellow oily liquid with an odor of Limburger cheese; [Hawley] White solid or colorless to light yellow solution with an unpleasant odor; [CAMEO] Clear colorless liquid with a stench; [MSDSonline]

OILY COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR.

colourless to very pale yellow, oily liquid/cheesy, sweat-like odour

Oily liquid

Characteristic goat-like odor

396 to 397 °F at 760 mmHg (NTP, 1992)

205.8 °C

202.00 to 203.00 °C. @ 760.00 mm Hg

205 °C @760 [mm Hg]

27 °F (NTP, 1992)

-4.00 to -3.00 °C. @ 760.00 mm Hg

220 °F (NTP, 1992)

215 °F (102 °C) (Open cup)

102 °C o.c.

5 to 10 mg/mL at 72 °F (NTP, 1992)

In water, 1.03X10+4 mg/L at 25 °C

Readily sol in ethanol, ether.

10.3 mg/mL

Solubility in water, g/100ml at 20 °C: 1.1

miscible with alcohol, most fixed oils, ether, 1 ml in 250 ml water

(in ethanol)

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

0.929 at 20 °C/4 °C

Relative density (water = 1): 0.93

0.923-0.928

0.9295 @25 °C

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

4.01 (Air = 1)

Relative vapor density (air = 1): 4.0

0.2 mmHg at 68 °F ; 1 mmHg at 158 °F; 20 mmHg at 233.2 °F (NTP, 1992)

0.04 [mmHg]

Vapor pressure, Pa at 20 °C: 27

0.18 [mm Hg] @20 °C

log Kow = 1.92

Henry's Law constant = 7.58X10-7 atm cu m/mol at 25 °C

716 °F (NTP, 1992)

716 °F (380 °C)

When heated to decomposition it emits acrid smoke and fumes.

Slightly water soluble.

Acids, Carboxylic

CAPROIC ACID is a carboxylic acid. Carboxylic acids donate hydrogen ions if a base is present to accept them. They react in this way with all bases, both organic (for example, the amines) and inorganic. Their reactions with bases, called "neutralizations", are accompanied by the evolution of substantial amounts of heat. Neutralization between an acid and a base produces water plus a salt. Carboxylic acids with six or fewer carbon atoms are freely or moderately soluble in water; those with more than six carbons are slightly soluble in water. Soluble carboxylic acid dissociate to an extent in water to yield hydrogen ions. The pH of solutions of carboxylic acids is therefore less than 7.0. Many insoluble carboxylic acids react rapidly with aqueous solutions containing a chemical base and dissolve as the neutralization generates a soluble salt. Carboxylic acids in aqueous solution and liquid or molten carboxylic acids can react with active metals to form gaseous hydrogen and a metal salt. Such reactions occur in principle for solid carboxylic acids as well, but are slow if the solid acid remains dry. Even "insoluble" carboxylic acids may absorb enough water from the air and dissolve sufficiently in it to corrode or dissolve iron, steel, and aluminum parts and containers. Carboxylic acids, like other acids, react with cyanide salts to generate gaseous hydrogen cyanide. The reaction is slower for dry, solid carboxylic acids. Insoluble carboxylic acids react with solutions of cyanides to cause the release of gaseous hydrogen cyanide. Flammable and/or toxic gases and heat are generated by the reaction of carboxylic acids with diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides. Carboxylic acids, especially in aqueous solution, also react with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), to generate flammable and/or toxic gases and heat. Their reaction with carbonates and bicarbonates generates a harmless gas (carbon dioxide) but still heat. Like other organic compounds, carboxylic acids can be oxidized by strong oxidizing agents and reduced by strong reducing agents. These reactions generate heat. A wide variety of products is possible. Like other acids, carboxylic acids may initiate polymerization reactions; like other acids, they often catalyze (increase the rate of) chemical reactions. This compound reacts with bases, oxidizing agents and reducing agents. (NTP, 1992).

... Can react with oxidizing materials.

The CIR Expert Panel concluded that the following ingredients are safe in the present practices of use andconcentration described in the safety assessment when formulated to be non-irritating and non-sensitizing, which may be basedon a QRA...Caproic Acid...

Safe for use in cosmetics, with qualifications

No indication of carcinogenicity to humans (not listed by IARC).

The substance can be absorbed into the body by inhalation of its aerosol and through the skin.

Cough. Sore throat.

Redness. Pain.

Redness. Pain. Blurred vision.

Dermatotoxin - Skin burns.

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

LC50 (mice) = 4,100 mg/m3/2h

LD50 Rat oral 3.0 g/kg

LD50 Mouse ip 3180 mg/kg /From table/

LD50 Mouse sc 3180 mg/kg /From table/

LD50 Mouse iv 1725 mg/kg /From table/

For more Non-Human Toxicity Values (Complete) data for HEXANOIC ACID (6 total), please visit the HSDB record page.

Rates of ketone body (beta-hydroxybutyrate plus acetoacetate) production by perfused livers from starved rats were decreased about 60% from 39 + or - 2 to 17 + or - 3 umol/g/hr by 2-ethylhexanol (200 uM), a primary metabolite of the plasticizer diethylhexyl phthalate. Rates of ketone body production in the presence of oleate (250 uM), which requires transport of the corresponding CoA compound into mitochondria, were reduced from 80 + or - 6 to 58 + or - 8 umol/g/hr by ethylhexanol. In contrast, ketone body production from hexanoate, which is activated in the mitochondria, was not affected by ethylhexanol.

Hexanoate and octanoate inhibit the triiodothyronine (T3) induced increases in the activities of malic enzyme and fatty acid synthase in chick embryo hepatocytes in culture. Butanoate was less effective as an inhibitor, and palmitate, stearate, and oleate had no effect or small stimulatory effects. Hexanoate and octanoate inhibited the lipogenic enzyme activities at a transcriptional step, and did so within 30 min of addition. Incubation for 2 hr in the absence of fatty acid reversed the inhibition of transcription caused by hexanoate. The inhibitory effect of hexanoate was selective because DNA content and transcription of the glyceraldehyde-3-phosphate dehydrogenase and beta-actin genes were not inhibited. Hexanoate mediated inhibition of transcription rates of the lipogenic genes was not correlated with an inhibition of binding of triiodothyronine to its nuclear receptor. 2-Bromooctanoate and carnitine stimulated the triiodothyronine induced accumulation of the mRNAs for malic enzyme and fatty acid synthase. The presence of hexanoate stimulated by 2 to 3 fold the increase caused by carnitine, suggesting that hexanoate and carnitine may regulate lipogenic gene expression by a common pathway. The active inhibitor may be a metabolite derived from hexanoate or octanoate, possibly an intermediate derived from an acyl-CoA derivative.

/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/

/LABORATORY ANIMALS: Acute Exposure/ Rats exposed to air saturated with caproic acid vapor for 8 hr suffered no fatalities.[Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. 5:718]

/LABORATORY ANIMALS: Acute Exposure/ Caproic acid is a mild skin irritant and severe eye irritant in rabbits. A mild response occurred in rabbits when 10 mg of the compound or 465 mg was applied to open skin patches for 24 hr; a 15% solution of caproic acid produced severe burns of the rabbit cornea.[Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. 5:718]

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ Male Fischer 344 rats fed caproic acid for 3 weeks at dietary concentrations of 2, 4, or 8% (by weight) showed no changes in liver size, liver to body-weight ratio, serum lipids, or peroxisome-related enzymes.[Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. 5:718]

/LABORATORY ANIMALS: Developmental or Reproductive Toxicity/ As with other saturated carboxylic acids, caproic acid caused microencephaly and other abnormalities in frog embryos. The degree of potency in the series of acids increased with hydrophobicity.[Bingham, E.; Cohrssen, B.; Powell, C.H.; Patty's Toxicology Volumes 1-9 5th ed. John Wiley & Sons. New York, N.Y. (2001)., p. 5:718]

For more Non-Human Toxicity Excerpts (Complete) data for HEXANOIC ACID (6 total), please visit the HSDB record page.

LC50 Lepomis macrochirus (Bluegill) >150-<200 mg/L/24 hr; static /formulated product/

LC50 Daphnia magna 22 mg/L/24 hr /Conditions of bioassay not specified in source examined/

LC50 Gammarus (Hyale plumulosa; Isopod) 235 mg/L/96 hr /Conditions of bioassay not specified in source examined/

LC50 Pimephales promelas (Fathead minnow) 140 mg/L/1 hr, static bioassay in Lake Superior water at 18-22 °C

For more Ecotoxicity Values (Complete) data for HEXANOIC ACID (11 total), please visit the HSDB record page.

The substance is harmful to aquatic organisms.

Hexanoic acid's production and use in the manufacture of esters for artificial flavors, rubber chemicals, varnish driers, resins and pharmaceuticals, may result in its release to the environment through various waste streams. Hexanoic acid occurs in milk fats and essential oils of various plants. If released to air, an extrapolated vapor pressure of 0.0435 mm Hg at 25 °C indicates hexanoic acid will exist solely as a vapor in the ambient atmosphere. Vapor-phase hexanoic 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 3 days. If released to soil, hexanoic acid is expected to have very high mobility based upon measured Koc values in the range of 24 to 37. The pKa of hexanoic acid is 4.88, which indicates it will exist primarily as an anion under environmental conditions. Volatilization from moist soil surfaces will not be an important fate process because anions do not volatilize. Hexanoic acid is not expected to volatilize from dry soil surfaces based upon its extrapolated vapor pressure. Hexanoic acid was readily degraded in a variety of screening tests, which suggest that it will biodegrade in the environment. If released into water, hexanoic acid is not expected to adsorb to suspended solids and sediment based upon the Koc data. Volatilization will not be an important fate process in water since anions do not volatilize. Carboxylic acids are generally resistant to aqueous environmental hydrolysis. An estimated BCF of 3 suggests the potential for bioconcentration in aquatic organisms is low. Occupational exposure to hexanoic acid may occur through inhalation and dermal contact with this compound at workplaces where hexanoic acid is produced or used. Monitoring data indicate that the general population may be exposed to hexanoic acid through the ingestion of food and water, and the inhalation of ambient air, particularly in areas where emissions from automobile traffic are high. (SRC)

Hexanoic acid occurs in milk fats (about 2%), in coconut oil (<1%), and in various palm and other oils(1). Hexanoic acid is emitted to the atmosphere in emissions from food decay, animal waste and vegetation(2).

Hexanoic acid's production and use in the manufacture of esters for artificial flavors(1), rubber chemicals, varnish driers, resins and pharmaceuticals(2), may result in its release to the environment through various waste streams(SRC). Hexanoic acid is also released to the environment from a variety of anthropogenic sources, especially automobile emissions(3).

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 26, 24 and 37 measured, for an acidic forest soil (pH 2.8, 4.85% organic carbon), agricultural soil (pH 6.7, 1.25% organic carbon), and a lake sediment (pH 7.1, 1.58% organic carbon), respectively(2), indicate that hexanoic acid is expected to have very high mobility in soil(SRC). Furthermore, the pKa of hexanoic acid is 4.88(3), indicating it will exist primarily as an anion under environmental conditions and anions generally possess greater mobility in soils than neutral compounds(4). Volatilization from moist soil surfaces will not be an important environmental fate process since anions do not volatilize(SRC). Hexanoic acid is not expected to volatilize from dry soil surfaces(SRC), based upon an extrapolated vapor pressure of 0.0435 mm Hg at 25 °C(5). Hexanoic acid was shown to biodegrade quickly in a variety of screening tests(6-8), suggesting that it will be susceptible to biodegradation in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), a Koc value of 37 measured in lake sediment(2), indicates that hexanoic acid is not expected to adsorb to suspended solids and sediment(SRC). The pKa of hexanoic acid is 4.88(3), indicating it will exist primarily as an anion under environmental conditions. Volatilization from water surfaces is not an important environmental fate process since anions do not volatilize(SRC). According to a classification scheme(4), an estimated BCF of 3(SRC), from a log Kow of 1.92(5) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Hexanoic acid was shown to biodegrade quickly in aqueous screening tests(7-9), suggesting that it will be susceptible to biodegradation in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), hexanoic acid, which has an extrapolated vapor pressure of 0.0435 mm Hg at 25 °C(2), is expected to exist solely in the vapor-phase in the ambient atmosphere. Vapor-phase hexanoic 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 days(SRC), calculated from its rate constant of 5.5X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3).

AEROBIC: A 5-day theoretical BOD of 44% was observed for hexanoic acid in an aerobic screening test using a sewage inoculum(1). Five and 20-day theoretical BODs of 66 and 87% were observed in another aerobic screening test using a sewage inoculum(2). Using a Warburg respirometer, an adapted sewage inoculum and 10,000 ppm concns of hexanoic acid, respective 5-, 10- and 20-day theoretical BODs of 29, 66 and 69% were measured under aerobic conditions(3). One-day theoretical BODs of 26-54% were determined in a Warburg respirometer using various activate sludge inocula(4). Five-day theoretical BODs of 98-99% were achieved in an aerobic screening study using acclimated activated sludge inoculum(5). Respective 2-, 5-, 10- and 30-day theoretical BODs of 42, 48, 54 and 65% were measured in an aerobic Warburg respirometer study using sewage inoculum(6). Using a Warburg respirometer and activated sludge inocula from three Tennessee municipal plants, theoretical BODs of 34.9-61.2% were measured over a 3-day inoculation period(7).

ANAEROBIC: Using an anaerobic reactor system, hexanoic acid was found to be readily metabolized by enriched methane cultures(1).

The rate constant for the vapor phase reaction of hexanoic acid with photochemically produced hydroxyl radicals has been estimated to be 5.5X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 3 days at an atmospheric concn of 5X10+5 hydroxyl radicals per cu cm(1). Carboxylic acids are generally resistant to aqueous environmental hydrolysis(2).

An estimated BCF of 3 was calculated for hexanoic acid(SRC), using a log Kow of 1.92(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).

LC50 Lepomis macrochirus (Bluegill) >150-<200 mg/L/24 hr; static /formulated product/

LC50 Daphnia magna 22 mg/L/24 hr /Conditions of bioassay not specified in source examined/

LC50 Gammarus (Hyale plumulosa; Isopod) 235 mg/L/96 hr /Conditions of bioassay not specified in source examined/

LC50 Pimephales promelas (Fathead minnow) 140 mg/L/1 hr, static bioassay in Lake Superior water at 18-22 °C

For more Ecotoxicity Values (Complete) data for HEXANOIC ACID (11 total), please visit the HSDB record page.

The substance is harmful to aquatic organisms.

Hexanoic acid's production and use in the manufacture of esters for artificial flavors, rubber chemicals, varnish driers, resins and pharmaceuticals, may result in its release to the environment through various waste streams. Hexanoic acid occurs in milk fats and essential oils of various plants. If released to air, an extrapolated vapor pressure of 0.0435 mm Hg at 25 °C indicates hexanoic acid will exist solely as a vapor in the ambient atmosphere. Vapor-phase hexanoic 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 3 days. If released to soil, hexanoic acid is expected to have very high mobility based upon measured Koc values in the range of 24 to 37. The pKa of hexanoic acid is 4.88, which indicates it will exist primarily as an anion under environmental conditions. Volatilization from moist soil surfaces will not be an important fate process because anions do not volatilize. Hexanoic acid is not expected to volatilize from dry soil surfaces based upon its extrapolated vapor pressure. Hexanoic acid was readily degraded in a variety of screening tests, which suggest that it will biodegrade in the environment. If released into water, hexanoic acid is not expected to adsorb to suspended solids and sediment based upon the Koc data. Volatilization will not be an important fate process in water since anions do not volatilize. Carboxylic acids are generally resistant to aqueous environmental hydrolysis. An estimated BCF of 3 suggests the potential for bioconcentration in aquatic organisms is low. Occupational exposure to hexanoic acid may occur through inhalation and dermal contact with this compound at workplaces where hexanoic acid is produced or used. Monitoring data indicate that the general population may be exposed to hexanoic acid through the ingestion of food and water, and the inhalation of ambient air, particularly in areas where emissions from automobile traffic are high. (SRC)

Hexanoic acid occurs in milk fats (about 2%), in coconut oil (<1%), and in various palm and other oils(1). Hexanoic acid is emitted to the atmosphere in emissions from food decay, animal waste and vegetation(2).

Hexanoic acid's production and use in the manufacture of esters for artificial flavors(1), rubber chemicals, varnish driers, resins and pharmaceuticals(2), may result in its release to the environment through various waste streams(SRC). Hexanoic acid is also released to the environment from a variety of anthropogenic sources, especially automobile emissions(3).

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 26, 24 and 37 measured, for an acidic forest soil (pH 2.8, 4.85% organic carbon), agricultural soil (pH 6.7, 1.25% organic carbon), and a lake sediment (pH 7.1, 1.58% organic carbon), respectively(2), indicate that hexanoic acid is expected to have very high mobility in soil(SRC). Furthermore, the pKa of hexanoic acid is 4.88(3), indicating it will exist primarily as an anion under environmental conditions and anions generally possess greater mobility in soils than neutral compounds(4). Volatilization from moist soil surfaces will not be an important environmental fate process since anions do not volatilize(SRC). Hexanoic acid is not expected to volatilize from dry soil surfaces(SRC), based upon an extrapolated vapor pressure of 0.0435 mm Hg at 25 °C(5). Hexanoic acid was shown to biodegrade quickly in a variety of screening tests(6-8), suggesting that it will be susceptible to biodegradation in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), a Koc value of 37 measured in lake sediment(2), indicates that hexanoic acid is not expected to adsorb to suspended solids and sediment(SRC). The pKa of hexanoic acid is 4.88(3), indicating it will exist primarily as an anion under environmental conditions. Volatilization from water surfaces is not an important environmental fate process since anions do not volatilize(SRC). According to a classification scheme(4), an estimated BCF of 3(SRC), from a log Kow of 1.92(5) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Hexanoic acid was shown to biodegrade quickly in aqueous screening tests(7-9), suggesting that it will be susceptible to biodegradation in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), hexanoic acid, which has an extrapolated vapor pressure of 0.0435 mm Hg at 25 °C(2), is expected to exist solely in the vapor-phase in the ambient atmosphere. Vapor-phase hexanoic 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 days(SRC), calculated from its rate constant of 5.5X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3).

AEROBIC: A 5-day theoretical BOD of 44% was observed for hexanoic acid in an aerobic screening test using a sewage inoculum(1). Five and 20-day theoretical BODs of 66 and 87% were observed in another aerobic screening test using a sewage inoculum(2). Using a Warburg respirometer, an adapted sewage inoculum and 10,000 ppm concns of hexanoic acid, respective 5-, 10- and 20-day theoretical BODs of 29, 66 and 69% were measured under aerobic conditions(3). One-day theoretical BODs of 26-54% were determined in a Warburg respirometer using various activate sludge inocula(4). Five-day theoretical BODs of 98-99% were achieved in an aerobic screening study using acclimated activated sludge inoculum(5). Respective 2-, 5-, 10- and 30-day theoretical BODs of 42, 48, 54 and 65% were measured in an aerobic Warburg respirometer study using sewage inoculum(6). Using a Warburg respirometer and activated sludge inocula from three Tennessee municipal plants, theoretical BODs of 34.9-61.2% were measured over a 3-day inoculation period(7).

ANAEROBIC: Using an anaerobic reactor system, hexanoic acid was found to be readily metabolized by enriched methane cultures(1).

The rate constant for the vapor phase reaction of hexanoic acid with photochemically produced hydroxyl radicals has been estimated to be 5.5X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 3 days at an atmospheric concn of 5X10+5 hydroxyl radicals per cu cm(1). Carboxylic acids are generally resistant to aqueous environmental hydrolysis(2).

An estimated BCF of 3 was calculated for hexanoic acid(SRC), using a log Kow of 1.92(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).

Koc values of 26, 24 and 37 have been experimentally measured, for an acidic forest soil (pH 2.8, 4.85% organic carbon), agricultural soil (pH 6.7, 1.25% organic carbon), and a lake sediment (pH 7.1, 1.58% organic carbon), respectively(1). According to a classification scheme(2), these measured Koc values suggest that hexanoic acid is very highly mobile in soil(SRC). In addition, the pKa of hexanoic acid is 4.88(3), indicating that this compound will primarily exist as an anion in the environment, and anions generally possess high mobility in soil(4).

The pKa of hexanoic acid is 4.88(1), indicating that this compound will exist predominantly as an anion under environmental conditions. Volatilization will not occur from water and moist soils since anions do not volatilize(SRC). Hexanoic acid is not expected to volatilize from dry soil surfaces(SRC), based upon an extrapolated vapor pressure of 0.0435 mm Hg at 25 °C(2).

DRINKING WATER: Hexanoic acid was identified, not quantified, in drinking water samples collected from treatment facilities in Cincinnati, OH (Oct 17, 1978 and Jan 14, 1980), Philadelphia, PA (Feb 10, 1976), Poplarville, MS (Mar 2, 1979), Miami, FL (Feb 3, 1976), New Orleans, LA (Jan 14, 1976) and Ottumwa, IO (Sep 10, 1976)(1).

SURFACE WATER: Hexanoic acid has been identified (concn generally <0.1 ug/L) in water samples collected from the River Lee in Great Britain(1). Hexanoic acid concns of 0.3 to 6.2 ug/L have been detected in river water samples collected from the Ohio and Little Miami rivers and from Tanners Creek (sampled dates or specific location not reported)(2).

GROUNDWATER: Ground water collected from a well near a landfill site in Norman, OK contained a hexanoic acid at 1.1 ug/L(1).

RAINWATER: Hexanoic acid was identified, not quantified, in rainwater samples collected in Hannover, Germany in 1986(1). Hexanoic acid was detected in rain and snow samples obtained from Southern California at levels of 0.008 to 0.44 uM (0.93 to 51.11 ug/L)(2). Hexanoic acid was detected in snow samples obtained from locations in Russia and Finland at levels of 0.08 to 0.47 ug/kg(3).

A hexanoic acid concn of 1.8 mg/L was detected in a trench leachate sample collected from a low-level radioactive waste disposal site in Maxey Flats, KY in May of 1978(1). Hexanoic acid concns of 9.6 to 420 ug/L were detected in primary and secondary effluents from four un-named sewage treatment plants(2). Hexanoic acid was detected at a concn of 0.063 ppb in gasoline automobile exhaust collected from a 1982 model Toyota Corolla(3); it has been estimated that the emission rate of hexanoic acid from motor vehicles in the south coast air basin of CA is 180 kg/day(4). Wastewater effluents collected from the Los Angeles County waste treatment plant in 1980 and 1981 contained hexanoic acid levels of 55 ug/L(5). Levels of 5-1470 ppb have been detected in wastewaters from coal gasification and shale oil processing(6). Spent wastewater from a sulfite pulping processed contained 0.3-1 g hexanoic acid/ton pulp(7). Hexanoic acid was identified at levels ranging from 0.058 to 0.249 ppb in the exhaust of 5 different automobiles(8).

SEDIMENT: Hexanoic acid was identified, not quantified, in the sediment from 3 rivers and a port in Niigata, Japan(1).

URBAN/SUBURBAN: Mean atmospheric concns of 0.006-0.063 ppb hexanoic acid were detected in ambient air samples collected in Los Angeles, CA in Jul and Sep 1984(1). Hexanoic acid was detected in the indoor air of manufactured homes at levels of 0.3-5.5 ppb (geometric mean = 1.2 ppb) and newly constructed homes at levels of 0.5-2.0 ppb (geometric mean = 1.0 ppb)(2). Hexanoic acid was detected in the air of Southern California in October 1984 at levels of 0.004-0.027 ppb(3). The average concn of hexanoic acid in the air of Long Beach, Los Angeles, Azusa, and Claremont, CA was 0.32, 0.48, 0.52, and 0.27 ug/cu m, respectively during a photochemical smog event in the summer of 1993(4).

RURAL/REMOTE: The concentration at a background remote location (San Nicolas Island, off the southwest coast of California) was measured as 0.02 ug/cu m(1).

Hexanoic acid concns of 1.2-12.3 mg/L were detected in various fruit dessert wines and fruit brandies(1). Trace quantities of hexanoic acid (<10 ug/kg)in mature guava fruit were detected, while 982 ug/kg were detected in over-ripe guava fruits(2). Hexanoic acid has been qualitatively detected in volatile constituents of baked potatoes(3) and fried chicken(4). Hexanoic acid was detected in the volatile emissions of two types of rice cakes at levels of 250 and 280 ppb(5). Hexanoic acid was identified in popcorn at a level of 400 ug/kg(6).

Hexanoic acid has been detected in the essential oils of Juniperus turkestanica and noble laurel plants(1).

Mussels (Mytilus edulis) collected from the Oarai Coast in Ibaraki, Japan in July 1985 contained a hexanoic acid concn of 0.05 ug/g(1).

Hexanoic acid occurs in milk fats (about 2%)(1).

Hexanoic acid was detected in roadside dust samples collected in southern California at levels of 1.3 and 9.5 nmols/g (0.15 to 1.10 ug/g)(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 10,060 workers (3,562 of these are female)are potentially exposed to hexanoic acid in the USA(1). Occupational exposure occurs through inhalation and dermal contact with this chemical at workplaces were hexanoic acid is produced and used(SRC). Monitoring data indicate that the general population may be exposed to hexanoic acid through the ingestion of food and water, and the inhalation of ambient air, particularly in areas where automobile emissions are high(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.

The following wastewater treatment technology has been investigated for caproic acid: Concentration process: Activated carbon.

The following wastewater treatment technology has been investigated for caproic acid: Concentration process: Resin adsorption.

/GUIDE 153: SUBSTANCES - TOXIC and/or CORROSIVE (Combustible)/ Fire or Explosion: Combustible material: may burn but does not ignite readily. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form.

/GUIDE 153: SUBSTANCES - TOXIC and/or CORROSIVE (Combustible)/ Health: TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

/GUIDE 153: SUBSTANCES - TOXIC and/or CORROSIVE (Combustible)/ Public Safety: CALL Emergency Response Telephone Number on Shipping Paper first. If Shipping Paper not available or no answer, refer to appropriate telephone number listed on the inside back cover. As an 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. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate enclosed areas.

/GUIDE 153: SUBSTANCES - TOXIC and/or CORROSIVE (Combustible)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible.

For more DOT Emergency Guidelines (Complete) data for HEXANOIC ACID (8 total), please visit the HSDB record page.

UN 2829; Caproic acid

IMO 8.0; Caproic acid

49 314 34; Hexanoic Acid

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

Corrosive

Do not transport with food and feedstuffs.

UN Hazard Class: 8; UN Pack Group: III