1H-Pyrrole

67.091

67.09

203-724-7

86S1ZD6L2C

72470|62777

DTXSID5021910

Colorless liquid when fresh|Yellowish or brown oil

2933990090

15.8

0.75

Liquid

0.9698 g/cm³ @ Temp: 20 °C

-23.4 °C

129.7 °C

102 DEG F (39 DEG C) (CLOSED CUP)

n 20/D 1.508(lit.)

H2O: 45 mg/mL at 25 °C

0-6ºC

8.7 hPa (20 °C)

2.31 (Air= 1)

LD50 orally in Rabbit: 137 mg/kg

3.10-14.8%(V)

Agreeable empyreumatic odor resembling that of chloroform

Burning, pungent taste

1.10e-10 cm3/molecule*sec

1.80e-05 atm-m3/mole|Henry's Law constant = 1.80X10-5 atm-cu m/mol @ 25 °C

pKa= 17.5|pKa = -3.80 (protonated form) (conjugate acid)

Polymerizes under influence of acids and glycols; soln in dil hydrogen chloride yield pyrrole red, an amorphous, orange-colored substance|Decomposes in acid; Conversion factors: 1 mg/l= 3.64 ppm; 1 ppm= 2.74 mg/cu m|Hydroxyl radical rate constant = 1.1X10-10 cu m/molc-sec @ 25 °C|Hygroscopic

-2.2418X10+9 J/kmol

10.79 kcla/mol @ 25 °C

Critical temperature: 366.75 °C; Critical pressure: 6.21X10+6 Pa

III

3

UN 1992 3/PG 3

2

R10;R20;R25;R41

26-37/39-45-39-24-16

UX9275000

T

Stable. Incompatible with strong acids, strong oxidizing agents. Combustible.

P280-P301 + P310-P305 + P351 + P338

H226-H301-H318-H332

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

... CAN REACT WITH OXIDIZING MATERIALS.|Violent reaction with 2-nitrobenzaldehyde.

UN 1993

|Warning|H400 (100%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]|P273, P391, and P501|The GHS information provided by 1 company from 1 notification to the ECHA C&L Inventory.|H226 (12.57%): Flammable liquid and vapor [Warning Flammable liquids]|P210, P233, P240, P241, P242, P243, P264, P270, P280, P301+P312, P303+P361+P353, P330, P370+P378, P403+P235, and P501|Aggregated GHS information provided by 1472 companies from 11 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H226: Flammable liquid and vapor [Warning Flammable liquids]|P210, P233, P240, P241, P242, P243, P280, P303+P361+P353, P370+P378, P403+P235, and P501

IN VIEW OF THE COMPOUND'S RELATIVELY LOW TOXICITY, ORDINARY HANDLING PRECAUTIONS INCLUDING USE OF GLOVES & GOOD VENTILATION ARE ADEQUATE TO PREVENT INJURY.

Flammable liquid when exposed to heat or flame ...

FOAM, CARBON DIOXIDE, DRY CHEMICAL.

| 2 - Materials that, under emergency conditions, can cause temporary incapacitation or residual 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.

Results of a study of several sites show that prior to coal gasification by ground water, pyrrole was not detected (limits of detection were 0.1 ppb). However, once coal gasification began, pyrrole was detected at 208 ppm in Hanna, Wyoming and 111 ppm Gillete, Wyoming. Pyrrole was not detected from low-Btu gasification of Rosebud coal but was detected at 23 ppm from an in situ oil shale process (limits of detection were 0.1 ppb)(1). Two retort wastewaters selected for study were produced from January to May, 1979 in the modified in situ retort 6 at the Occidental Oil Shale, Inc. facility at Logan Wash, CO. In the condensate retort water, 4.9 mg/l of pyrrole was detected while no pyrrole was detected at the process retort water (detection limits not specified)(2). Pyrrole was detected from shale oil wastewaters used to cool hot spent shale, both in gas condensate water and process retort water units not specified(3).

Pyrrole is a constituent of creosote which is a compound used as a wood preservative, especially in electric poles. Due to this, pyrrole may be found in soil in locations where creosote has been used(1).

SOURCE DOMINATED: Pyrrole was detected at <1 ng/ml of air above 1 ml of water in 10 ml samples from two process retort wastewaters collected at Laramie Energy Technology Center during May 1982 and at the Logan Wash site of Occidental Oil Shale Inc. during December 1987; it was also detected in the gas-condensate retort wastewaters at 3.1 and 5.0 ng/ml of air above 1 ml of water at both sites(1). Pyrrole has been found in stock emission during incineration of municipal waste units not specified(2). URBAN/SUBURBAN: Pyrrole was not detected in ambient air at either Logan Wash, CO or at Boulder, CO(1).

LD50 Mouse sc 61 mg/kg|LD50 Mouse ip 98 mg/kg

Pyrrole's production and presence in creosote(1), chemical intermediate in drug manufacturing(2) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 61(SRC), determined from a log Kow of 0.75(2) and a regression-derived equation(3), indicates that pyrrole is expected to have high mobility in soil(SRC). Volatilization of pyrrole from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 1.8X10-5 atm-cu m/mole(4). The potential for volatilization of pyrrole from dry soil surfaces may exist(SRC) based upon a vapor pressure of 8.35 mm Hg(5). Pyrrole does not readily undergo biodegradation in water unless there exists bacteria that have had previous exposure to pyrrole. Given this need for acclimation, the decomposition of pyrrole may be very slow(6).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 61(SRC), determined from a log Kow of 0.75(2), indicates that pyrrole is not expected to adsorb to suspended solids and sediment in water(SRC). Volatilization from water sources is expected(3) based upon a Henry's Law constant of 1.80X10-5 atm-cu m/mole(4). Volatilization half-lives for a model river and model lake are 42 hrs and 368 hrs, respectively(SRC), using an estimation method(3). According to a classification scheme(5), an estimated BCF of 2(3,SRC) from a log Kow of 0.75(2) suggests the potential for bioconcentration in aquatic organisms is low. Experiments have shown that pyrrole is actually degraded by gasoline-adapted ground water cultures when present as a single substrate. Adaption time was 480 hrs and degradation time was 600 hrs(6). Pyrrole was not degraded in a mixture of compounds in water after 1100-1300 hrs at 10 °C and at a concentration of 0.2-1 mg/l(6).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), pyrrole, which has a vapor pressure of 8.35 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase pyrrole 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 4 days(SRC) from its rate constant of 1X10-10 cu cm/molecule sec(3). In a comparison of room temperature rate constants and loss rates of selected organics in the presence of 7.2X10+11 molecule/cu cm of ozone, 5X10+5 molecule/cu cm of hydroxyl radicals, and 2.4X10+8 molecules/cu cm of NO3 radicals, pyrrole displayed the following rate constants: 1.6X10-17 cu cm/molecule sec with a loss rate of 1 day, 1.2X10-11 cu cm/molecule sec with a loss rate of 5.2 days, and 4.9X10-11 cu cm/molecule sec with a loss rate of 1000 days, respectively(4).

The rate constant for the vapor-phase reaction of pyrrole with photochemically-produced hydroxyl radicals is 1X10-10 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 4 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Pyrrole is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(2) nor to directly photolyze due to the lack of absorption in the environmental UV spectrum (>290 nm). A rate constant of 8.71X10+9 mole-1 sec-1 with hydroxyl radicals in aqueous solution was estimated for pyrrole using structure-reactivity relationships (SRR) and linear free-energy relationships (LFER)(3). The -log of the rate constant of pyrrole reacting with nitrate radical in the gas phase at 298 K is 10.338(4) with a half life of 3.62 sec(SRC) assuming a concentration of 1.5X10+13 in the ambient environment under dark conditions(5).

An estimated BCF of 2 was calculated for pyrrole(SRC), using a log Kow of 0.75(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is low.

The Koc of pyrrole is estimated as approximately 61(SRC), using a log Kow of 0.75(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that pyrrole is expected to have high mobility in soil.

The Henry's Law constant for pyrrole is 1.8X10-5 atm-cu m/mole(1). This Henry's Law constant indicates that pyrrole is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as approximately 42 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as approximately 368 hours(SRC). Pyrrole's Henry's Law constant(1) indicates that volatilization from moist soil surfaces may occur(SRC). The potential for volatilization of pyrrole from dry soil surfaces may exist(SRC) based upon a vapor pressure of 8.35 mm Hg(3).

GROUNDWATER: Pyrrole was detected in 1 of 5 groundwater samples collected from Fredericia(Jutland) Denmark in 1992 at a concentration of 0.22 ug/l(1). Pyrrole is introduced into groundwater through the use of creosote on wooden electric poles(2).

Pyrrole has been detected in "popped" popcorn at a level of 26 ug/kg in a dry capture method and 44 ug/kg in a wet capture method(1). Fresh chicken breast with bone was cut into 1.5 inch cubes, coated with flour and fried in Fri-al shortening. During a 48 hour period in which the chicken was fried, pyrrole was detected (detection level not specified)(2).

Occupational exposure to pyrrole may occur through inhalation and dermal contact with this compound at workplaces where pyrrole is produced or used. The general population may be exposed to pyrrole via ingestion of food, and dermal contact with this compound and creosote containing pyrrole. (SRC)

IT HAS A DEPRESSANT ACTION ON THE CENTRAL NERVOUS SYSTEM AND, IN SEVERE INTOXICATION, IS INJURIOUS TO THE LIVER.|NO CASES OF OCCUPATIONAL DISEASE DUE TO PYRROLE HAVE BEEN REPORTED; HOWEVER TESTS INDICATE THAT IT HAS A MODERATE CUMULATIVE TOXICITY.

Pyrrole

GRADE: TECHNICAL.

1H-Pyrrole: ACTIVE|STUDY OF FREE RADICALS PRODUCED IN PYRROLE BY X IRRADIATION & TRITIUM ATOM DECAY.|A constituent of coal tar & bone oil ... .|Pyrrole was found to be potentially useful as a tracer for determining the contribution of environmental tobacco smoke to concentrations of volatile organic compounds in indoor environments with smoking.|The ability of 10 pyrroles to block the acidic nitrosation of morpholine has been determined by using an assay that measures their effectiveness in the presence of a 10-fold excess of amine. The log (% N-nitrosomorpholine) formed is a linear function of blocking agent concentrations ranging from 0.0 to 1.5 times the equivalents of initial nitrate. The negative slopes of these plots allow a ranking of the effectiveness of the blocking agent. Several of the pyrroles have been found to be much more effective than establishing blocking agents such as ascorbic acid. The following order blocking ability has been determined: 2,5-dimethylpyrrole = 1-benzyl-2,5-dimethylpyrroleic acid = 1,2-phenylenediamine = pyrrole > 1,2,5-tribenzylpyrrole = 1-benzylpyrrole = octamethylporphine hydrazine = 2,5-diphenylpyrrolecarboxylic acid. Pyrroles give complex mixtures devoid of N-nitroso compounds upon nitrosation.

Runge test with hydrochloric acid yields pyrrole red, an amorphous polymer mixture. In addition, all pyrroles with a free alpha or beta position or with groups, eg. ester, that can be converted to such pyrroles under acid conditions undergo the Ehrlich reaction with p(dimethylamino) benzaldehyde to give a purple product. Pyrrole reacts with selenium dioxide in the presence of nitric acid to give a deep violet solution. Very small quantities (4X10-5 g) of pyrrole can be detected in this method.

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