Isobutyric Acid

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

H312: Harmful in contact with skin [Warning Acute toxicity, dermal]

P264, P270, P280, P301+P317, P302+P352, P317, P321, P330, P362+P364, and P501 (click each P-code to see the statement)

H226 (11.9%): Flammable liquid and vapor [Warning Flammable liquids]

H302 (99.3%): Harmful if swallowed [Warning Acute toxicity, oral]

H311 (11.3%): Toxic in contact with skin [Danger Acute toxicity, dermal]

H312 (88.7%): Harmful in contact with skin [Warning Acute toxicity, dermal]

H314 (10.2%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H318 (10%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

P210, P233, P240, P241, P242, P243, P260, P262, P264, P264+P265, P270, P280, P301+P317, P301+P330+P331, P302+P352, P302+P361+P354, P303+P361+P353, P304+P340, P305+P354+P338, P316, P317, P321, P330, P361+P364, P362+P364, P363, P370+P378, P403+P235, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 2003 reports by companies from 18 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.

H226: Flammable liquid and vapor [Warning Flammable liquids]

H301: Toxic if swallowed [Danger Acute toxicity, oral]

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]

H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

P210, P233, P240, P241, P242, P243, P260, P261, P262, P264, P264+P265, P270, P271, P280, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P303+P361+P353, P304+P340, P305+P354+P338, P316, P317, P319, P321, P330, P361+P364, P363, P370+P378, P403+P233, P403+P235, 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.

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

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

INHALATION: move to fresh air.

INGESTION: give large amounts of water.

EYES: flush with water for at least 15 min.; get medical attention if irritation persists.

SKIN: flush with water. (USCG, 1999)

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.

· In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin.

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 132 [Flammable Liquids - Corrosive]:

Some of these materials may react violently with water.

SMALL FIRE: Dry chemical, CO2, water spray or alcohol-resistant foam.

LARGE FIRE: Water spray, fog or alcohol-resistant foam. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal. Do not get water inside containers.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. 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. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2024)

Use alcohol-resistant foam, powder, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water.

Extinguish with dry chemical, alcohol foam, or carbon dioxide.

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, dry chemical or carbon dioxide. 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.

· All equipment used when handling the product must be grounded.

· Do not touch or walk through spilled material.

· Stop leak if you can do it without risk.

· Prevent entry into waterways, sewers, basements or confined areas.

· A vapor-suppressing foam may be used to reduce vapors.

· Absorb with earth, sand or other non-combustible material.

· For hydrazine, absorb with DRY sand or inert absorbent (vermiculite or absorbent pads).

· Use clean, non-sparking tools to collect absorbed material.

Large Spill

· Dike far ahead of liquid spill for later disposal.

· Water spray may reduce vapor, but may not prevent ignition in closed spaces.

Excerpt from ERG Guide 132 [Flammable Liquids - Corrosive]:

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

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 for at least 50 meters (150 feet) in all directions.

· 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.

Remove all ignition sources. Collect leaking and spilled liquid in covered containers as far as possible. Wash away remainder with plenty of water.

Environmental considerations: Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash or cement powder. Neutralize with agricultural lime (CaO), crushedd limestone (CaCO3) or sodium bicarbonate (NaHCO3). /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be contained with a flexible impermeable membrane liner./

Environmental considerations: Water spill: Neutralize with agricultural lime (CaO), crushed limestone (CaCO3), or sodium bicarbonate (NaHCO3). If dissolved, in region of 10 ppm or greater concentration, apply activated carbon at ten times the spilled amount. Use mechanical dredges or lifts to remove immobilized masses of pollutants and precipitates.

Environmental considerations: Air spill: Apply water spray or mist to knock down vapors. Vapor knockdown water is corrosive or toxic and should be diked for containment.

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.

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. ... Avoid breathing vapors. Keep upwind. Avoid bodily contact with the material. Do not handle broken packages without 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.

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 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 appropriate chemical protective clothing.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. Quality assurance to ascertain the completeness of the cleaning procedures should be implemented before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at end of shift, but should remain at employee's place of work for cleaning.

Excerpt from ERG Guide 132 [Flammable Liquids - Corrosive]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. A vapor-suppressing foam may be used to reduce vapors. Absorb with earth, sand or other non-combustible material. For hydrazine, absorb with DRY sand or inert absorbent (vermiculite or absorbent pads). Use clean, non-sparking tools to collect absorbed material.

LARGE SPILL: Dike far ahead of liquid spill for later disposal. Water spray may reduce vapor, but may not prevent ignition in closed spaces. (ERG, 2024)

Fireproof. Separated from strong bases and 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.

0.80 [mg/m3]

8.8 [mg/m3]

53 [mg/m3]

· Some of these materials may react violently with water.

Small Fire

· Dry chemical, CO2, water spray or alcohol-resistant foam.

Large Fire

· Water spray, fog or alcohol-resistant foam.

· If it can be done safely, move undamaged containers away from the area around the fire.

· Dike runoff from fire control for later disposal.

· Do not get water inside containers.

Fire Involving Tanks, Rail Tank Cars or Highway Tanks

· Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles.

· 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.

· For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn.

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.

Organic chemical respirator; goggles or face shield; rubber gloves (USCG, 1999)

SRP: When working with strong solutions of acids or bases or other caustic or corrosive materials, always wear a full face mask. When working with caustic or corrosive gases or vapors, a full face mask will not protect the eyes or prevent inhaling the material. A full face respirator is required.

Personnel protection: Wear appropriate chemical protective gloves, boots and goggles.

NO open flames, NO sparks and NO smoking. Above 56 °C use a closed system, ventilation and explosion-proof electrical equipment.

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.

Isobutyric acid appears as a colorless liquid with a light odor of rancid butter. Corrosive to metals and tissue.

Colorless liquid; [Hawley] Pungent odor, but not as unpleasant as butyric acid; [Merck Index]

COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR.

colourless liquid with a strong penetrating odour of rancid butter

Colorless liquid

Pungent odor like that of butyric acid, but not as unpleasant

SHARP, BUTTER-FAT-LIKE ODOR

CHEESY TASTE

309 °F at 760 mmHg (USCG, 1999)

152-155 °C at 760 mm Hg

152-155 °C

-51 °F (USCG, 1999)

132 °F (NFPA, 2010)

170 °F OPEN CUP

132 °F (56 °C) (closed cup)

56 °C c.c.

Slightly soluble in carbon tetrachloride

Sol in 6 parts of water; miscible with alcohol, chloroform, and ether.

In water, 1.67X10+5 mg/L at 20 °C

167 mg/mL at 20 °C

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

miscible with alcohol, most fixed oils, glycerine and propylene glycol; insoluble in water

(in ethanol)

0.949 at 68 °F (USCG, 1999) - Less dense than water; will float

0.950 at 20 °C/4 °C

Relative density (water = 1): 0.95

0.944-0.948

0.949 @ 20°C

Relative vapor density (air = 1): 3.0

1.81 [mmHg]

1.81 mm Hg at 25 °C

Vapor pressure, kPa at 14.7 °C: 0.13

1 [mm Hg] @14.7 °C

log Kow = 0.94

Henry's Law constant = 8.85X10-7 atm-cu m/mol at 25 °C

Stable during transport.

935 °F (USCG, 1999)

When heated to decomposition it emits acrid smoke and fumes.

1.126 mPa.s

/2-Methylpropanoic acid/ is corrosive to metals.

Flammable. Water soluble

Acids, Carboxylic

ISOBUTYRIC ACID corrodes aluminum and other metals. Flammable hydrogen gas may accumulate in enclosed spaces in which this reaction has taken place (USCG, 1999).

2-Methylpropanoic acid can react with oxidizing materials.

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

Burning sensation. Cough. Sore throat.

Redness. Skin burns. Pain.

Pain. Redness. Severe deep burns.

Abdominal pain. Burning sensation. Shock or collapse.

Dermatotoxin - Skin burns.

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

LD50 Rat oral 2518 mg/kg

LD50 Rat oral 266 mg/kg

LD50 Rat oral 280 mg/kg

LD50 Rabbit oral 8000 mg/kg

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

/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Organic acids and related compounds/

/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/ In an open rabbit skin irritation test, isobutyric acid (0.01 mL, 10 mg) caused some necrosis in 24 hr.

/LABORATORY ANIMALS: Acute Exposure/ No fatalities occurred when rats inhaled air saturated with isobutyric acid vapor for 8 hr.

/LABORATORY ANIMALS: Acute Exposure/ Rated 9 on rabbit eyes. ... tested externally on eyes of rabbits & ... rated numerically on scale of 1-10 according to degree of injury ... after 24 hr /observation/, paying particular attention to condition of cornea. Most severe injuries have been rated 10.

/LABORATORY ANIMALS: Acute Exposure/ Isobutyric acid is moderately severe primary irritant to skin & eye in concentrated form. It is not a skin sensitizer.

For more Non-Human Toxicity Excerpts (Complete) data for ISOBUTYRIC ACID (10 total), please visit the HSDB record page.

EC50; Species: Xenopus laevis (African clawed frog, embryo); Conditions: freshwater, renewal, pH 7.0-7.8; Concentration: 2567400 ug/L for 96 hr (2092000-3041000 ug/L); Effect: increased developmental changes, general (craniofacial defects, abnormal gut coiling) /> or =98% purity/

LC50; Species: Xenopus laevis (African clawed frog, embryo); Conditions: freshwater, renewal, pH 7.0-7.8; Concentration: 7925000 ug/L for 96 hr (7392000-8351000 ug/L) /> or =98% purity/

EC50; Species: Daphnia magna (Water flea); Conditions: freshwater, pH 8; Concentration: 1000 mg/L for 24 hr; Effect: behavior, equilibrium /Conditions of bioassay not specified in source examined/

LC50; Species: Leuciscus idus melanotus (Carp); Conditions: freshwater; Concentration: 175 mg/L for 48 hr /Conditions of bioassay not specified in source examined/

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

The substance is harmful to aquatic organisms.

Isobutyric acid's use in the production of fibers, resins, plastics and dyestuffs, its use as an intermediate in the manufacture of pharmaceuticals, cosmetics, food additives, and in its use as a starting material for diisopropyl ketone may result in its release to the environment through various waste streams. The use of its as textile chemicals, tanning compounds, stabilizers, catalysts and preservatives may also result in its release to the environment through various waste streams. Its former use as an herbicide resulted in its direct release to the environment. Isobutyric acid is found in Dalieb (Borassus aethiopum l.) fruit, earth almonds (Cyperus esculentus l.) and 9 hop varieties and is produced during the intermediary hepatic and microbial metabolism of valine. If released to air, a vapor pressure of 1.81 mm Hg at 25 °C indicates isobutyric acid will exist solely as a vapor in the atmosphere. Vapor-phase isobutyric 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 8 days. If released to soil, isobutyric acid is expected to have high mobility based upon an estimated Koc of 77. The pKa of isobutyric acid is 4.84, indicating that this compound will exist almost entirely 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 because anions do not volatilize. Isobutyric acid may volatilize from dry soil surfaces based upon its vapor pressure. Aerobic biodegradation of isobutyric acid is unknown; however, under anaerobic conditions, isobutyric acid was metabolized by an enriched acetate culture cross acclimated with isobutyric acid at a rate of 250 mg/L following a 3 day lag period. If released into water, isobutyric acid is expected to adsorb to suspended solids and sediment based upon the estimated Koc. The pKa indicates isobutyric acid will exist almost entirely in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces is not expected to be an important fate process. An estimated BCF of 3 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 isobutyric acid may occur through inhalation and dermal contact with this compound at workplaces where isobutyric acid is produced or used. Monitoring data indicate that the general population may be exposed to isobutyric acid via inhalation of ambient air, ingestion of food and drinking water, and dermal contact with this compound and other consumer products containing isobutyric acid. (SRC)

REPORTED FOUND IN SEVERAL ESSENTIAL OILS: ARNICA MONTANA, ROMAN CAMOMILE, LAURUS NOBILIS, IMPERATORIA, & IN CAROB FRUITS (SILIQUA DULCIS); ALSO IDENTIFIED IN ESSENCE OF SESELI TORTUOSUM, ARTEMISIA TRANSILIENSIS, & IN STRAWBERRY AROMA.

Isobutyric acid is a naturally occurring component of food (cheese, butter, milk protein, vinegar, and beer) and feedstuffs, and is produced during the intermediary hepatic and microbial metabolism of valine. Isobutyric acid ... is present in human feces, presumably due to action of intestinal microflora.

20 Fatty acids were identified and quantified in 9 hop varieties. Major components included /isobutyric acid/ ... responsible for the cheesy off-flavor of stored hops. ... Mycrene-rich varieties contained high amounts of /isobutyric acid/.

Isobutyric acid was detected in Dalieb (Borassus aethiopum L.) fruit at 25 mg/kg of pulp(1). Isobutyric acid was identified as a volatile component of earth almonds (Cyperus esculentus L.)(2).

For more Natural Pollution Sources (Complete) data for ISOBUTYRIC ACID (6 total), please visit the HSDB record page.

Isobutyric acid's use in the production of fibers, resins, plastics and dyestuffs, its use as an intermediate in the manufacture of pharmaceuticals, cosmetics, food additives(1), and in its use as a starting material for diisopropyl ketone(2) may result in its release to the environment through various waste streams(SRC). The use of its salts as textile chemicals, tanning compounds, stabilizers, catalysts and preservatives(2) may also result in its release to the environment through various waste streams. Its former use as an herbicide(2) resulted in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 77(SRC), determined from a log Kow of 0.94(2) and a regression-derived equation(3), indicates that isobutyric acid is expected to have high mobility in soil(SRC). The pKa of isobutyric acid is 4.84(4), indicating that this compound will exist almost entirely in 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 from moist soil surfaces is not expected to be an important fate process because anions do not volatilize. Isobutyric acid is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.81 mm Hg(6). Aerobic biodegradation data were not available(SRC, 2008); however, under anaerobic conditions, isobutyric acid was metabolized by an enriched acetate culture cross acclimated with isobutyric acid at a rate of 250 mg/L following a 3 day lag period(7).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 77(SRC), determined from a log Kow of 0.94(2) and a regression-derived equation(3), indicates that isobutyric acid is expected to adsorb to suspended solids and sediment(SRC). A pKa of 4.84(4) indicates isobutyric acid will exist almost entirely in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces is not expected to be an important fate process(5). The half-life for isobutyric acid reacting with photochemically generated hydroxyl radicals in water has been calculated to be 1.7 years based on a reaction rate constant of 1.26X10+9 L/mol-sec(6) and a hydroxyl radical concn of 1X10-17 mol/L(7). According to a classification scheme(8), an estimated BCF of 3(SRC), from its log Kow(2) and a regression-derived equation(9), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Aerobic biodegradation data were not available(SRC, 2008); however, under anaerobic conditions, isobutyric acid was metabolized by an enriched acetate culture cross acclimated with isobutyric acid at a rate of 250 mg/L following a 3 day lag period(10).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), isobutyric acid, which has a vapor pressure of 1.81 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase isobutyric 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 8 days(SRC), calculated from its rate constant of 2.0X10-12 cu cm/molecule-sec at 25 °C(3).

ANAEROBIC: Isobutyric acid is reported to be susceptible to anaerobic biodegradation(1). Under anaerobic conditions, isobutyric acid was metabolized by an enriched acetate culture cross acclimated with isobutyric acid at a rate of 250 mg/L following a 3 day lag period(2).

The rate constant for the vapor-phase reaction of isobutyric acid with photochemically-produced hydroxyl radicals has been measured as 2.0X10-12 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 8 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The half-life for isobutyric acid reacting with photochemically generated hydroxyl radicals in water has been calculated to be 1.7 years based on a reaction rate constant of 1.26X10+9 L/mol-sec(2) and a hydroxyl radical concn of 1X10-17 mol/L(3). Isobutyric acid is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(4).

An estimated BCF of 3 was calculated in fish for isobutyric acid(SRC), using a log Kow of 0.94(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 isobutyric acid is estimated as 77(SRC), using a log Kow of 0.94(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that isobutyric acid is expected to have high mobility in soil. The pKa of isobutyric acid is 4.84(4), indicating that this compound will exist almost entirely in 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).

EC50; Species: Xenopus laevis (African clawed frog, embryo); Conditions: freshwater, renewal, pH 7.0-7.8; Concentration: 2567400 ug/L for 96 hr (2092000-3041000 ug/L); Effect: increased developmental changes, general (craniofacial defects, abnormal gut coiling) /> or =98% purity/

LC50; Species: Xenopus laevis (African clawed frog, embryo); Conditions: freshwater, renewal, pH 7.0-7.8; Concentration: 7925000 ug/L for 96 hr (7392000-8351000 ug/L) /> or =98% purity/

EC50; Species: Daphnia magna (Water flea); Conditions: freshwater, pH 8; Concentration: 1000 mg/L for 24 hr; Effect: behavior, equilibrium /Conditions of bioassay not specified in source examined/

LC50; Species: Leuciscus idus melanotus (Carp); Conditions: freshwater; Concentration: 175 mg/L for 48 hr /Conditions of bioassay not specified in source examined/

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

The substance is harmful to aquatic organisms.

Isobutyric acid's use in the production of fibers, resins, plastics and dyestuffs, its use as an intermediate in the manufacture of pharmaceuticals, cosmetics, food additives, and in its use as a starting material for diisopropyl ketone may result in its release to the environment through various waste streams. The use of its as textile chemicals, tanning compounds, stabilizers, catalysts and preservatives may also result in its release to the environment through various waste streams. Its former use as an herbicide resulted in its direct release to the environment. Isobutyric acid is found in Dalieb (Borassus aethiopum l.) fruit, earth almonds (Cyperus esculentus l.) and 9 hop varieties and is produced during the intermediary hepatic and microbial metabolism of valine. If released to air, a vapor pressure of 1.81 mm Hg at 25 °C indicates isobutyric acid will exist solely as a vapor in the atmosphere. Vapor-phase isobutyric 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 8 days. If released to soil, isobutyric acid is expected to have high mobility based upon an estimated Koc of 77. The pKa of isobutyric acid is 4.84, indicating that this compound will exist almost entirely 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 because anions do not volatilize. Isobutyric acid may volatilize from dry soil surfaces based upon its vapor pressure. Aerobic biodegradation of isobutyric acid is unknown; however, under anaerobic conditions, isobutyric acid was metabolized by an enriched acetate culture cross acclimated with isobutyric acid at a rate of 250 mg/L following a 3 day lag period. If released into water, isobutyric acid is expected to adsorb to suspended solids and sediment based upon the estimated Koc. The pKa indicates isobutyric acid will exist almost entirely in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces is not expected to be an important fate process. An estimated BCF of 3 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 isobutyric acid may occur through inhalation and dermal contact with this compound at workplaces where isobutyric acid is produced or used. Monitoring data indicate that the general population may be exposed to isobutyric acid via inhalation of ambient air, ingestion of food and drinking water, and dermal contact with this compound and other consumer products containing isobutyric acid. (SRC)

REPORTED FOUND IN SEVERAL ESSENTIAL OILS: ARNICA MONTANA, ROMAN CAMOMILE, LAURUS NOBILIS, IMPERATORIA, & IN CAROB FRUITS (SILIQUA DULCIS); ALSO IDENTIFIED IN ESSENCE OF SESELI TORTUOSUM, ARTEMISIA TRANSILIENSIS, & IN STRAWBERRY AROMA.

Isobutyric acid is a naturally occurring component of food (cheese, butter, milk protein, vinegar, and beer) and feedstuffs, and is produced during the intermediary hepatic and microbial metabolism of valine. Isobutyric acid ... is present in human feces, presumably due to action of intestinal microflora.

20 Fatty acids were identified and quantified in 9 hop varieties. Major components included /isobutyric acid/ ... responsible for the cheesy off-flavor of stored hops. ... Mycrene-rich varieties contained high amounts of /isobutyric acid/.

Isobutyric acid was detected in Dalieb (Borassus aethiopum L.) fruit at 25 mg/kg of pulp(1). Isobutyric acid was identified as a volatile component of earth almonds (Cyperus esculentus L.)(2).

For more Natural Pollution Sources (Complete) data for ISOBUTYRIC ACID (6 total), please visit the HSDB record page.

Isobutyric acid's use in the production of fibers, resins, plastics and dyestuffs, its use as an intermediate in the manufacture of pharmaceuticals, cosmetics, food additives(1), and in its use as a starting material for diisopropyl ketone(2) may result in its release to the environment through various waste streams(SRC). The use of its salts as textile chemicals, tanning compounds, stabilizers, catalysts and preservatives(2) may also result in its release to the environment through various waste streams. Its former use as an herbicide(2) resulted in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 77(SRC), determined from a log Kow of 0.94(2) and a regression-derived equation(3), indicates that isobutyric acid is expected to have high mobility in soil(SRC). The pKa of isobutyric acid is 4.84(4), indicating that this compound will exist almost entirely in 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 from moist soil surfaces is not expected to be an important fate process because anions do not volatilize. Isobutyric acid is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.81 mm Hg(6). Aerobic biodegradation data were not available(SRC, 2008); however, under anaerobic conditions, isobutyric acid was metabolized by an enriched acetate culture cross acclimated with isobutyric acid at a rate of 250 mg/L following a 3 day lag period(7).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 77(SRC), determined from a log Kow of 0.94(2) and a regression-derived equation(3), indicates that isobutyric acid is expected to adsorb to suspended solids and sediment(SRC). A pKa of 4.84(4) indicates isobutyric acid will exist almost entirely in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces is not expected to be an important fate process(5). The half-life for isobutyric acid reacting with photochemically generated hydroxyl radicals in water has been calculated to be 1.7 years based on a reaction rate constant of 1.26X10+9 L/mol-sec(6) and a hydroxyl radical concn of 1X10-17 mol/L(7). According to a classification scheme(8), an estimated BCF of 3(SRC), from its log Kow(2) and a regression-derived equation(9), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Aerobic biodegradation data were not available(SRC, 2008); however, under anaerobic conditions, isobutyric acid was metabolized by an enriched acetate culture cross acclimated with isobutyric acid at a rate of 250 mg/L following a 3 day lag period(10).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), isobutyric acid, which has a vapor pressure of 1.81 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase isobutyric 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 8 days(SRC), calculated from its rate constant of 2.0X10-12 cu cm/molecule-sec at 25 °C(3).

ANAEROBIC: Isobutyric acid is reported to be susceptible to anaerobic biodegradation(1). Under anaerobic conditions, isobutyric acid was metabolized by an enriched acetate culture cross acclimated with isobutyric acid at a rate of 250 mg/L following a 3 day lag period(2).

The rate constant for the vapor-phase reaction of isobutyric acid with photochemically-produced hydroxyl radicals has been measured as 2.0X10-12 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 8 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The half-life for isobutyric acid reacting with photochemically generated hydroxyl radicals in water has been calculated to be 1.7 years based on a reaction rate constant of 1.26X10+9 L/mol-sec(2) and a hydroxyl radical concn of 1X10-17 mol/L(3). Isobutyric acid is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(4).

An estimated BCF of 3 was calculated in fish for isobutyric acid(SRC), using a log Kow of 0.94(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 isobutyric acid is estimated as 77(SRC), using a log Kow of 0.94(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that isobutyric acid is expected to have high mobility in soil. The pKa of isobutyric acid is 4.84(4), indicating that this compound will exist almost entirely in 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).

A pKa of 4.84(1) indicates isobutyric acid will exist almost entirely in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces and moist soil is not expected to be an important fate process(2). Isobutyric acid is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.81 mm Hg(3).

DRINKING WATER: Isobutyric acid was tentatively identified in drinking water from Cincinnati, OH during 1980 and Philadelphia, PA during 1976(1). Isobutyric acid was identified as an ozone disinfection by-product in drinking water samples from a pilot plant in Jefferson Parish, LA which uses Mississippi River was as the raw water source; samples were collected following 4 rounds of ozonation treatment performed in January, 1994, August 1994, May 1995, and September 1996(2).

GROUNDWATER: Groundwater samples taken from wells in the Besos basin, Northeast Spain were found to contain <5 ng/L of isobutyric acid(1). Isobutyric acid was detected in ground water at a concn of 2 ug/L in Galloway Township, NJ, Feb 1990(2). Isobutyric acid was detected at different depths at a site in Pensacola, FL from 0.00 to 3.32 mg/L in 1985(3).

During 1974, isobutyric acid was tentatively identified in water at an advanced waste treatment plant in Pomona, CA(1). Isobutyric acid was detected in retort water from Australian oil shales at a concn of 31 ppm(2). Oil retort water from Occidental Oil Shale Inc. contained 119 mg/L of isobutyric acid(3). Isobutyric acid has been qualitatively identified in effluents from the following industries: paint and ink, textile mills, auto and other laundries and organic chemicals(4). Isobutyric acid was found at a concn of 16.5 g/L in one year old leachate(5). Isobutyric acid was found in leachate from landfill for municipal wastes in Japan at a concn of 5280 ug/L(6). Taichung (Taiwan) sanitary landfill leachates contained isobutyric acid at concns of 153 ug/ml(7). Isobutyric acid was found in trench leachate samples taken from low level radioactive waste disposal sites in Maxey Flats, KY and West Valley, NY at a concn ranging from 0.40 to 3.6 ppm and 12 to 21 ppm, respectively(8). Isobutyric acid was detected in Norman, OK landfill well water at a concn of 48.6ug/L(9). Isobutyric acid was detected in the goundwater at the site of a wood treatment facility in Pensacola, FL at a maximum concn of 2.49 ppm(10). Isobutyric acid was found in groundwater below a municipal landfill in Norman, OK at an estimated concn of 48.7 ppb(11). Isobutyric acid was found in kitchen waste exudate and building materials with microbial growth(12). Exhaust from gasoline and diesel powered automobiles had total isobutyric acid concns of 0.165-0.54 ppbv(13). Isobutyric acid was detected in used automobile motor oil at a concn of 88 ppb and automobile gas exhaust at a concn of 0.056 ppb(14).

Isobutyric acid was not detected in soil samples from the UCLA campus, Los Angeles, CA tested in October 1984(1).

URBAN/SUBURBAN: During 1984, isobutyric acid was monitored in the atmosphere of Los Angeles, CA at concn ranging from 0.003 to 0.056 ppb(1). Isobutyric acid was detected at 0.17, 0.25, 0.32 and 0.35 ug/cu m in Long Beach, Los Angeles, Azusa and Claremont, CA, respectively, Sept 8-9, 1993(2). Isobutyric acid was found at 0.0021-0.014, 0.005-0.006, 0.0045-0.02, and 0.009-0.014 ppbv at UCLA campus, Newberry Park, Monterey Park, and La Habra, CA, respectively, in October 1984(3).

RURAL/REMOTE: Isobutyric acid was detected at 0.02 ug/cu m on San Nicolas Island, CA, September 8-9, 1993(1).

INDOOR: Isobutyric acid was found in a greenhouse at 0.0039-0.0042 ppbv(1).

Isobutyric acid has been identified as a volatile flavor component of Idaho Russet Burbank baked potatoes(1). Isobutyric acid was identified as a volatile component of raw and roasted earth almonds (Cyperus esculentus L.)(2), in Korean red pine (Pinus densiflora) sprout tea(3), in strawberry jam(4) and in Italian-type dry-cured ham(5). Isobutyric acid was detected in Dalieb (Borassus aethiopum L.) fruit at 25 mg/kg of pulp(6).

Isobutyric acid was identified as a volatile component of earth almonds (Cyperus esculentus L.)(1). Isobutyric acid was detected in Dalieb (Borassus aethiopum L.) fruit at 25 mg/kg of pulp(2).

Isobutyric acid was identified in rotten mussels (Mytilus edulis) at 10.9 ug/g wet weight(1).

Isobutyric acid was found in trench leachate samples taken from low level radioactive waste disposal sites in Maxey Flats, KY and West Valley, NY at a concn ranging from 0.40 to 3.6 ppm and 12 to 21 ppm, respectively(1).

Isobutyric acid was detected in used automobile motor oil at a concn of 88 ppb and automobile gas exhaust at a concn of 0.056 ppb(1).

Isobutyric acid was detected in poultry manure from a large scale farm in Japan at concns from 0.43 to 68.5 mg/kg May 21, 1984(1). Isobutyric acid was found in dust samples taken from the UCLA campus at 1.9 nmol/g and not detected in dust collected in an apartment building in Monterey Park, CA(2).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 5052 workers (652 of these were female) were potentially exposed to isobutyric acid in the US(1). Occupational exposure to isobutyric acid may occur through inhalation and dermal contact with this compound at workplaces where isobutyric acid is produced or used. Monitoring data indicate that the general population may be exposed to isobutyric acid via inhalation of ambient air, ingestion of food and drinking water, and dermal contact with this compound and other consumer products containing isobutyric acid(SRC).

Annual consumption is 2650.00 lb. Individual consumption is 0.002245 mg/kg/day.

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.

/GUIDE 132: FLAMMABLE LIQUIDS - CORROSIVE/ Fire or Explosion: Flammable/combustible material. May be ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.

/GUIDE 132: FLAMMABLE LIQUIDS - CORROSIVE/ Health: May cause toxic effects if inhaled or ingested/swallowed. Contact with substance may cause severe burns to skin and eyes. Fire will produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution.

/GUIDE 132: FLAMMABLE LIQUIDS - CORROSIVE/ 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 for at least 50 meters (150 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate closed spaces before entering.

/GUIDE 132: FLAMMABLE LIQUIDS - CORROSIVE/ 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 ISOBUTYRIC ACID (8 total), please visit the HSDB record page.

UN 2529; Isobutyric acid

IMO 3.3; Isobutyric acid

49 314 38; Isobutyric 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.

Flammable Liquid Corrosive

Do not transport with food and feedstuffs.

Symbol: Xn; R: 21/22; S: (2)

UN Hazard Class: 3; UN Subsidiary Risks: 8; UN Pack Group: III