Isobutyric acid

88.11

88.11

635770

201-195-7

8LL210O1U0

0903

62780

2529

DTXSID4021636

Colorless liquid

2915600000

37.3

0.88

Clear colorless Liquid

0.950 g/cm³ @ Temp: 20 °C

-47 °C

152-155 °C @ Press: 760 Torr

132 °F

1.408

H2O: 210 g/L (20 ºC)

room temp

1.5 mm Hg ( 20 °C)

3.04 (vs air)

Oral-Rat LD50: 280 mg/kg

Combustible in case of open flame, high temperature and strong oxidant; burning emits irritating smoke

1.6-7.3%(V)

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

CHEESY TASTE

4.84(at 20 °C)

2.00e-12 cm3/molecule*sec

8.85e-07 atm-m3/mole|Henry's Law constant = 8.85X10-7 atm-cu m/mol at 25 °C

4.84 (at 20 °C)|pKa = 4.84

Hydroxyl radical reaction rate constant = 2.00X10-12 cu cm/molec-sec at 25 °C

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).

935 °F (USCG, 1999)|935 °F|481 °C

Lower flammable limit: 2.0% by volume, Upper flammable limit: 9.2% by volume

The vapour is heavier than air.

/2-Methylpropanoic acid/ is corrosive to metals.

11,182.8 g cal/g mole

Critical temp: 637 °F= 336 °C; Critical pressure: 588 psia= 40 atm= 4.06 MN/sq m

III

3

UN 2529 3/PG 3

1

21/22

23-36/37/39-24/25

NQ4375000

Xn

Complete packaging, light loading and unloading; warehouse ventilated, away from open flame, high temperature, stored separately from oxidants and alkalis

Stable during transport.

P210-P260-P280-P303 + P361 + P353-P305 + P351 + P338-P370 + P378

H226-H302-H311-H314

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.

2-Methylpropanoic acid can react with oxidizing materials.

Isobutyric acid is a food additive permitted for direct addition to food for human consumption as a synthetic flavoring substance and adjuvant in accordance with the following conditions: a) they are used in the minimum quantity required to produce their intended effect, and otherwise in accordance with all the principles of good manufacturing practice, and 2) they consist of one or more of the following, used alone or in combination with flavoring substances and adjuvants generally recognized as safe in food, prior-sanctioned for such use, or regulated by an appropriate section in this part.|Since 1994, dietary supplements have been regulated under the Dietary Supplement Health and Education Act (DSHEA). The DSHEA requires no proof of safety for dietary supplements on the market prior to October 15, 1994. Labeling requirements for such supplements allow warnings and dosage recommendations as well as substantiated "structure or function" claims. All claims must prominently note that they have not been evaluated by the FDA, and they must bear the statement "This product is not intended to diagnose, treat, cure, or prevent any disease".

European Chemicals Bureau; IUCLID Dataset, Isobutyric acid (CAS #79-31-2) (2000 CD-ROM edition). Available from the Database Query page at: http://ecb.jrc.it/esis/esis.php as of February 29, 2008.

Excerpt from ERG Guide 132 [Flammable Liquids - Corrosive]: 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. (ERG, 2016)|Flammable. Gives off irritating or toxic fumes (or gases) in a fire. Above 56 °C explosive vapour/air mixtures may be formed.|Flammable - 2nd degree

|Warning|H302: Harmful if swallowed [Warning Acute toxicity, oral]|P264, P270, P280, P301+P312, P302+P352, P312, P322, P330, P363, and P501|H226 (10.78%): Flammable liquid and vapor [Warning Flammable liquids]|P210, P233, P240, P241, P242, P243, P264, P270, P280, P301+P312, P302+P352, P303+P361+P353, P312, P322, P330, P363, P370+P378, P403+P235, and P501|Aggregated GHS information provided by 1966 companies from 16 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|Danger|H226: Flammable liquid and vapor [Warning Flammable liquids]|P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P280, P301+P310, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P321, P322, P330, P361, P363, P370+P378, P403+P233, P403+P235, P405, and P501

Excerpt from ERG Guide 132 [Flammable Liquids - Corrosive]: As an immediate precautionary measure, isolate spill or leak area for at least 50 meters (150 feet) in all directions. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck 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, 2016)

Excerpt from ERG Guide 132 [Flammable Liquids - Corrosive]: Fully encapsulating, vapor-protective clothing should be worn for spills and leaks with no fire. ELIMINATE all ignition sources (no smoking, flares, sparks or flames in 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 and transfer to containers (except for Hydrazine). 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, 2016)

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.

/2-Methylpropanoic acid/ is combustible.|Moderate fire hazard when exposed to heat or flame.

Explosive limits , vol% in air: 2-9

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.

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.

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.

/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.

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.

Isobutyric acid is moderately severe primary irritant to skin & eye in concentrated form. It is not a skin sensitizer.|Strong irritant to tissue.

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

Fireproof. Separated from strong bases and food and feedstuffs.

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.

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.

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

| 3 - Materials that, under emergency conditions, can cause serious or permanent injury.| 2 - Materials that must be moderately heated or exposed to relatively high ambient temperatures before ignition can occur. Materials would not under normal conditions form hazardous atmospheres with air, but under high ambient temperatures or under moderate heating could release vapor in sufficient quantities to produce hazardous atmospheres with air.| 0 - Materials that in themselves are normally stable, even under fire conditions.

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 5000 lb or 2270 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).

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 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).

highly toxic

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.

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).

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).

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).

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).

(11)C-isobutyrate showed initial accum of activity in liver & diffusely throughout abdomen & variable retention in heart-blood pool. This distribution pattern may reflect equilibration of carboxylates with fatty tissue having high perfusion rates where metab can occur.|(1-14)C-isobutyric acid was admin by gavage to male rats at doses of 4, 40 & 400 mg/kg body wt & to females at 400 mg/kg. It was rapidly eliminated in breath as (14)co2. Urine avg 3.5% of dose. Fecal excretion was less than 1% of dose. Plasma clearance was rapid.|/Isobutyric acid/ has been detected in human blood and saliva.|Isobutyric acid used as feed fungistat is unlikely to contribute to endogenous levels of isobutyric acid in flesh, eggs, or milk of grain-consuming animals.|Rats fed high doses of isobutyric acid excrete increased amounts of 2-methylmalonic acid in the urine (an intermediate in the conversion of propionic acid to succinic acid).

Isobutyric acid was rapidly metabolized to carbon dioxide in Charles River CD rats after gavage admin. At 4 hours, 75.4, 83.3 and 66.7% of the dose had been exhaled by male rats dosed with 4, 40 or 400 mg/kg, respectively. At 48 hours, 85-90% of the dose /had been exhaled/.|Isobutyric acid is metabolized to propionic acid which, in turn, is converted to succinic acid and ultimately to glucose and glycogen.|Male and female rats administered isobutyric acid by oral gavage (4 to 400 mg/kg) rapidly eliminated 70 to 80% of the dose as 14CO2 in the expired air within 4 hr and 90 to 96% in 48 hr; approximately 3 to 4% of the dose was present in the urine as [14C]urea, also formed from 14CO2.|Metabolism in dairy cattle is apparently rapid; there was no carryover of isobutyric acid into the milk of animals fed 170 mg/kg/day for 10 days, and no increases in the peripheral blood concentrations of isobutyric acid were found.

... The effect of butyrate and other short-chain carboxylic acids /were compared/ in transient expression studies with K562 cells using an expression plasmid bearing a luciferase reporter gene driven by the normal human A gamma-globin gene promoter. Butyrate (4 carbons) increased the activity of the human A gamma-globin gene promoter up to 123 times. Marked augmentation of the normal gamma-promoter activity was also noted with 5-carbon valeric acid (up to 394 times) and 3-carbon propionic acid (up to 129 times). The branched isobutyric acid as well as phenylacetate showed less ability to increase promoter activity. Addition of the tandemly repeated AP-1/NF-E2 (AP) enhancer sequences from hypersensitive site 2 (HS2) of the locus control region (LCR) increased gamma-promoter activity up to 24 times. Addition of a nearby 16-bp conserved motif (CM) in HS2 ... to the AP-containing plasmid construct further increased gamma-promoter activity. In the presence of butyrate, the plasmid bearing both the AP and CM sequences showed gene expression up to 477 times greater than that of the basal gamma-promoter-driven luciferase plasmid in the absence of inducer. A plasmid bearing the herpes simplex thymidine kinase promoter was also tested and gene expression was markedly increased by the same organic acids. MEL cells responded to butyrate, valerate, and propionate with induction of hemoglobin synthesis. Responses to isobutyrate and 6-carbon caproate required higher concentrations of the compounds. Thus, other short-chain organic acids as well as butyrate increase gamma-promoter activity in the transient expression system, and this activity can be further augmented by incorporating LCR elements into the expression vector. Nonglobin promoters also respond to the same carboxylic acids.|The inhibitory effects of isobutyric acid on activity of pepsin on synthetic dipeptide, n-carbobenzoxy-L-glutamyl-L-tyrosine, were studied to obtain evidence for the hypothesis which suggests that pepsin forms a hydrophobic bond with the nonpolar side chain or its substrates. Kinetic study showed that the inhibition by carboxylic acids was competitive, the inhibitor constant (Ki) decreasing with an increase in the size of inhibitor molecule. The free energy change of formation of complex between pepsin and the hydrocarbon chain of carboxylic acid increased linearly with the increase in the number of C atoms in the hydrocarbon chain of the inhibitor. The hydrophobic interaction between the side chain of amino acid residues in the binding region of the active center of pepsin and the hydrocarbon side chain of the inhibitor may be the probable cause of the inhibition.

Inhalation causes irritation of nose and throat. Ingestion causes irritation of mouth and stomach. Contact with eyes or skin causes irritation. (USCG, 1999)

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)

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.

/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/

2-methpropanoic acid

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.

Grade: Technical

All other basic organic chemical manufacturing|Propanoic acid, 2-methyl-: ACTIVE|TP - indicates a substance that is the subject of a proposed TSCA section 4 test rule.

DETERMINATION OF ISOBUTYRIC ACID IN AIR BY GAS CHROMATOGRAPHY. THE PRECOLUMN WAS HEATED TO 200 DEG IN 24 SEC, & EVOLVED GAS WAS DETERMINED. LINEAR CALIBRATION CURVE WAS OBTAINED FOR 2-4000 NANOGRAM FATTY ACID.|Isobutyric acid, used in the mfr of brufen, was determined by gas chromatography on a column of 10% polyethylene glycol adipate on BLK with flame-ionization detection. The sensitivity of the method was 1%.|Gas chromatography sep of mixtures of fatty acids, phenols, and indoles were effected with flexible fused silica capillary columns containing either volatile fatty acid, Carbowax 20M nondeactivated fused silica (VFA) or Carbowax 20M deactivated (Carbowax 20M), or SP-2100, Carbowax 20M deactivated (Methyl Silicone) and the respective chromatograms compared for artificial mixtures, for human urine, or for persian cat feces. Optimum conditions for the column were detected and fair to good separations were achieved.

Food additives -> Flavoring Agents|Flavoring Agents -> JECFA Flavorings Index|Fatty Acyls [FA] -> Fatty Acids and Conjugates [FA01] -> Branched fatty acids [FA0102]|Fire Hazards -> Flammable - 2nd degree|Cosmetics -> Buffering

Flavoring Agents