TECHNICAL SUPPORT DOCUMENT: 

BIOACCUMULATION AND PERSISTENCE DATA FOR 

SELECTED NITROARENES 

6-Nitrochrysene (7496-02-8) 

1,6-Dinitropyrene (42397-64-8) 

1,8-Dinitropyrene (42397-65-9) 

4-Nitropyrene (57835-92-4) 

Office of Environmental Information 

Environmental Analysis Division 

Analytical Support Branch 

November 2009 
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I. Introduction 

 This technical support document contains information on the bioaccumulation and 

persistence properties of four nitroarenes: 6-nitrochrysene (Chemical Abstracts Service Number 

(CAS No.) 7496-02-8); 1,6-dinitropyrene (CAS No. 42397-64-8); 1,8-dinitropyrene (CAS No. 

42397-65-9); and 4-nitropyrene (CAS No. 57835-92-4). Since there is little chemical specific 

persistence data for these nitroarenes, data on the persistence of 1-nitropyrene, a structural 

isomer of 4-nitropyrene and close chemical analog of the other nitroarenes, are presented. 

Structures of all five nitroarenes are presented below. 

O2N NO2 O2N

NO2

 1-Nitropyrene 4-Nitropyrene 1,6-Dinitropyrene 

O2N NO2

 

NO2

 1,8-Dinitropyrene 6-Nitrochrysene 

1-Nitropyrene is a member of the Emergency Planning and Community Right-to-Know 

Act (EPCRA) section 313 polycyclic aromatic compounds (PACs) category. The PACs category 

was designated as a category of persistent, bioaccumulative, toxic (PBT) chemicals in 1999 PBT 

chemical rule (October 29, 1999, 64 FR 58666). Data on the bioaccumulation and persistence 

properties of 1-nitropyrene were presented in that rulemaking and associated support documents 

(January 5, 1999, 64 FR 688; USEPA/OPPT, 1998; Aronson, D. et.al., 1998). 

II. Persistence Data 

1-Nitropyrene – PBT Rule Data: 

 The persistence data presented in the PBT Chemical Rule (January 5, 1999, 64 FR 688) 

for 1-nitropyrene included half-lives for air and surface water. The half-life in air was reported 

as a range of 10 hours to 4 days. The technical report for the persistence data (Aronson, D. et.al., 

1998) included the following summary comments concerning this data: 

“Based upon an estimated rate constant for the reaction of 1-nitropyrene with hydroxyl radicals 

in the vapor phase (Kwok and Atkinson, 1995). However, this compound is expected to exist 

mainly in the particulate phase in the atmosphere [based on a vapor pressure of 5.52x10-8 mm Hg 

(Neely and Blau, 1985)] which may result in longer half-lives. This compound is susceptible to 
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direct photolysis as shown by several laboratory studies using organic solvents (Fan et al. 1996; 

Holder et al., 1994; Koizumi et al., 1994).” 

 The half-lives in surface water were reported as a range of 16 to 44 years. The technical 

report for the persistence data (Aronson, D. et.al., 1998) included the following summary 

comments concerning this data: 

 “Half-lives given for the mineralization of 1-nitropyrene in two waters, an oil contaminated 

drainage pond (high t1⁄2) and a bay (low t1⁄2) (Heitkamp et al., 1991). Photolysis of 1-nitropyrene 

in surface waters may occur based on direct photolysis studies in organic solvents (Greenberg et 

al., 1987; Holloway et al., 1987; Koizumi et al., 1994); however, this compound is expected to 

adsorb to particulates and suspended material in the water and may be removed from the surface 

where photolysis will occur.” 

 No half-lives were presented for soil, but the technical report for the persistence data 

(Aronson, D. et.al., 1998) included the following summary comments about soil half lives: 

“No biodegradation studies were located for this compound in soil. 1-Nitropyrene is expected to 

be resistant to aerobic biodegradation based on results in water. Photolysis on the soil surface 

may occur based on laboratory results reported for 1-nitropyrene placed on glass surfaces and in 

organic solvents.” 

6-Nitrochrysene, 1,6-Dinitropyrene, 1,8-Dinitropyrene and 4-Nitropyrene: 

The analysis of the persistence of the four nitroarenes includes the previous data for 1-

nitropyrene plus some additional information mainly addressing persistence in air. 

1. Abiotic Degradation. 

The polycyclic ring structures of the nitroarenes absorb ultraviolet light at 

environmentally relevant wavelengths (greater than 290 nanometers (nm)) and are susceptible to 

direct photolysis in the atmosphere and in sun-lit waters (HSDB, 2009; Morel et al., 2006). 

Morel et al. (2006) observed major absorbance of ultraviolet light by 1,6- and 1,8-dinitropyrene 

at 245 nm, 284 nm, and also near 400 nm with a broad band characteristic of nitroaromatics 

Greenberg et al. (1987) measured about 70% decomposition of 1-nitropyrene, that was 

applied to a filter as a 0.1 milligrams per liter (mg/mL) methanol solution and exposed to 

sunlight and air for 14 days. Benson et al. (1985) reported a half-life of 533 hours for the 

degradation of 1 micromole (μmol) of 1-nitropyrene applied to a glass surface and exposed to 

natural sunlight for periods of 12 to 670 hours. 1-Nitropyrene at a concentration of 1 mg/mL in a 

benzene solution was degraded by 52.8% after 4 hours exposure to sunlight (Koizumi et al. 

1994). Half-lives measured for 1-nitropyrene exposed to light ≥ 310 nm were 1.2 days in 

dimethyl sulfoxide (DMSO) at 0.5 mg/mL and 6 days on silica plates at 133 (parts per million 

(ppm) (Holloway et al., 1987). Half-lives measured for 1,8-dinitropyrene following the same 

procedure were 0.7 days in DMSO and 5.7 days on silica plates. Morel et al. (2006) measured 

the photodegradation rates of 1,6- and 1,8-dinitropyrene in acetonitrile (4×10-5 molar (M)) 
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saturated with N2, O2, or containing 5.6 M H2O and exposed to artificial light. Half lives derived 

from the reported first-order rate constants ranged from 24 to 46 minutes for 1,6-dinitropyrene 

and 1.2 to 1.8 hours for 1,8-dinitropyrene (Morel et al., 2006). Although the actual wavelengths 

of light that caused this degradation were not specified, analysis of the products formed from this 

reaction indicated that the degradation took place through an energy transition that requires 

absorbance of the higher, environmentally relevant wavelengths. 

Most of the measured photolysis data reported above are for 1-nitropyrene. Although the 

behavior of this substance is expected to be representative of the photodegradation of the other 4-

ring nitroarenes, slight differences in structure can result in different rates of direct photolysis for 

these compounds (Morel et al., 2006). For example, the rate of direct photolysis for 1,6-

dinitropyrene in acetonitrile saturated with N2 and O2 was four times greater than the rate of 

direct photolysis for 1,8-dinitropyrene measured under the same conditions (Morel et al., 2006). 

No photodegradation data were located for 6-nitrochrysene or 4-dinitropyrene. 

The estimated rate constant for the reaction of 6-nitrochrysene and 4-nitropyrene with 

photochemically produced hydroxyl radicals in the atmosphere is approximately 6×10-12 cubic 

meters (cm3

)/molecule-second (sec) (U.S. EPA, 2008). This corresponds to a half-life of 

approximately 21 hours based on an atmospheric hydroxyl radical concentration of 1.5×106

molecules/cm3 and a 12-hour day. The estimated rate constant for the reaction of 1,6- and 1,8-

dinitropyrene with photochemically produced hydroxyl radicals in the atmosphere is 

approximately 5×10-13 cm3/molecule-sec (U.S. EPA, 2008). This corresponds to a half-life of 

approximately 20 days based on an atmospheric hydroxyl radical concentration of 1.5×106

molecules/cm3 and a 12-hour day. These values (21 hours for 6-nitrochrysene and 4-nitropyrene, 

20 days for 1,6- and 1,8-dinitropyrene) are somewhat higher than the range estimated for 1-

nitropyrene which was 1 hour to 4 days (Aronson, D. et.al., 1998). 

 

 The rates of photolysis and photooxidation are expected to be slower for nitroarenes that 

are adsorbed onto carbonaceous atmospheric particulates (high elemental carbon content) since 

the particulate matter can shield the adsorbed substance from incident light and attack from 

atmospheric radicals (Feilberg and Nielsen, 2000; Holder et al. 1994). Energy transfer from the 

adsorbed substance to the carbon surface may also hinder photolysis (Feilberg and Nielsen, 

2000). The composition of the particulate matter to which the nitroarene is adsorbed is expected 

to influence the rate of photodegradation. No photodegradation was observed for 1-nitropyrene 

adsorbed to unfractionated coal fly ash or to the carbonaceous fraction of this ash after 24 hours 

irradiation using a xenon arc lamp (Holder et al. 1994). However, the loss of 1-nitropyrene 

adsorbed to the ferromagnetic fraction, the mineral fraction, and to silica gel was 10-12%, 20-

21%, and 33-41%, respectively. Fan et al. (1996) reported that the degradation of 1- and 2-

nitropyrene adsorbed to wood smoke was more rapid than the degradation of these substances 

adsorbed to diesel soot particulates when exposed to natural sunlight. 

Hydrolysis is not expected to be an important removal mechanism for nitroarenes in the 

environment since these structures do not contain functional groups that hydrolyze under 

environmental conditions (Lyman et al., 1990). 
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2. Aerobic Biotic Degradation. 

Very little biodegradation data are available for the nitroarenes. Heitkamp et al. (1991) 

reported that less than 1% of 1-nitropyrene added to estuarine sediments was converted to CO2

after 8 weeks of aerobic incubation. These authors proposed that the aerobic degradation 

pathway proceeded through the formation of the 1-nitropyrene cis-9,10- and 4,5-dihydrodiols 

followed by ring cleavage. Pothuluri et al. (1998) studied the aerobic metabolism of 6-

nitrochrysene by the fungal species C. elegans and proposed a degradation pathway proceeding 

through the formation of 1- and 2-hydroxy-6-nitrochrysene followed by 6-nitrochrysene 1- and 

2-sulfate. 

 Measured rate data for the aerobic biodegradation of nitroarenes were not located. 

Biodegradation half-lives determined for the unsubstituted polycyclic aromatics chrysene and 

pyrene range from weeks to a few years (Aronson et al., 1999). Aerobic biodegradation of the 

nitroarenes is expected to proceed even more slowly than that of the unsubstituted compounds 

since the presence of nitro groups on aromatic rings makes these structures more resistant to 

aerobic biodegradation (Cerniglia and Somerville, 1995; Howard, 2000). 

3. Anaerobic Biotic Degradation. 

Heitkamp et al. (1991) reported that 0% of 1-nitropyrene, a structural isomer of 4-

nitropyrene, added to estuarine sediments was converted to CO2 after 8 weeks of anaerobic 

incubation. 1-Aminopyrene was detected as an anaerobic metabolite of 1-nitropyrene 

biodegradation during this process, indicating that nitroarenes are reduced to form aromatic 

amines under anaerobic conditions. The reduction of aromatic nitro groups under anaerobic 

conditions is well known (Boethling et al., 1995). 

III. Bioaccumulation Data 

As was done previously for 1-nitropyrene, and most of the other members of the PACs 

category, the bioconcentration factors (BCFs) for the four nitroarenes were calculated using 

estimated log Kow values and a regression-derived equation (USEPA/OPPT, 1998). The 

estimated BCF value for 1-nitropyrene cited in the PBT rule was 908 (January 5, 1999, 64 FR 

688, USEPA/OPPT, 1998). The regression equation used to estimate the BCF value for 1-

nitropyrene was: 

Equation 1: log BCF = 0.77 log Kow - 0.70 + correction factor 

The above equation is from version 2 of the SRC program (BCF WIN, the Bioconcentration 

Factor Estimation Program, version 2.0 (USEPA/OPPT, 1998)). The latest version of that 

program uses a revised equation (USEPA 2008): 

Equation 2: Log BCF = 0.6598 log Kow - 0.333 + correction factor 
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The results of the BCF estimations using both equations are presented in the table below, no 

correction factors were used for either equation. The estimated log Kow values used to calculate 

the BCF values are also listed in the table (USEPA 2008). 

Chemical Log Kow BCF equation 1 BCF equation 2 

1,6-dinitropyrene 4.57 660 480 

1,8-dinitropyrene 4.57 660 480 

6-nitrochrysene 5.34 2600 1600 

4-nitropyrene 4.75 910 630 

IV. References 

Aronson, D. et.al., (1998) Chemical Fate Half-Lives for Toxics Release Inventory (TRI) 

Chemicals. Prepared by Syracuse Research Corp. for Robert S. Boethling, USEPA Office of 

Pollution Prevention and Toxics, Washington, DC. July 30, 1998. SRC TR 98-008. 

Aronson, D; Citra, M, Shuler, K; et al. (1999) Aerobic biodegradation of organic chemicals in 

environmental media: A summary of field and laboratory studies. Prepared for U.S. 

Environmental Protection Agency, Athens, GA. 

Benson, J.M., Brooks, A.L., Cheng, Y.S., Henderson, T.R. and White, J.E. Environmental 

transformations of 1-nitropyrene on glass surfaces. Atmos. Environ. 19: 1169-1174. 1985. 

Boethling, RS; Howard, PH; Beauman, JA; et al. (1995) Factors for intermedia extrapolation in 

biodegradability assessment. Chemosphere 30(4):741–752. 

Cerniglia, CE; Somerville, CC. (1995) Reductive metabolism of nitroaromatic and 

nitropolycyclic aromatic hydrocarbons. In: Biodegradation of nitroaromatic compounds. New 

York, NY: Plenum Press, 99–115. 

Fan, Z., Kamens, R.M., Hu, J., Zhang, J. and McDow, S. Photostability of nitro-polycyclic 

aromatic hydrocarbons on combustion soot particles in sunlight. Environ. Sci. Technol. 30: 

1358-1364. 1996. 

Feilberg, A; Nielsen, T. (2000) Effect of aerosol chemical composition on the photodegradation 

of nitro-polycyclic aromatic hydrocarbons. Environ Sci Technol 34(5);789-797. 

Greenberg, A., Darack, F., Wang, Y., Harkov, R., Louis, J. and Atherholt, T. Fate of airborne 

PAH and nitro-PAH. Proceedings of the 80th Annual Meeting of the APCA. 6: 1-33. 1987. 

Heitkamp, M.A., Freeman, J.P., Miller, D.W. and Cerniglia, C.E. Biodegradation of 1-

nitropyrene. Arch. Microbiol. 156: 223-230. 1991. 
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Holder, P.S., Wehry, E.L. and Mamantov, G. Photochemistry transformation of 1-nitropyrene 

sorbed on coal fly ash fractions. Polycyclic Arom. Comp. 4: 135-139. 1994. 

Holloway, M.P., Biaglow, M.C., McCoy, E.C., Anders, M., Rosenkranz, H.S. and Howard, P.C. 

Photochemical instability of 1-nitropyrene, 3-nitrofluoranthene, 1,8-dinitropyrene and their 

parent polycyclic aromatic hydrocarbons. Mutat. Res. 187: 199-207. 1987. 

Howard, PH. (2000) Biodegradation. In: Property estimation methods for chemicals. Boca 

Raton, FL: Lewis Publishers, 281–310. 

HSDB (Hazardous Substances Data Bank). (2009) 1-Nitropyrene, chrysene, and pyrene. 

National Library of Medicine. Available online at http://toxnet.nlm.nih.gov. (accessed July 24, 

2009). 

Koizumi, A., Satioh, N., Suzuki, T. and Kamiyama, S. A novel compound, 9-hydroxy-1-pyrene, 

is a major photodegraded compound of 1-nitropyrene in the environment. Arch. Environ. Health. 

49: 87-93. 1994. 

Kwok, E.S.C. and Atkinson, R. Estimation of hydroxyl radical reaction rate constants for gasphase organic compounds using a structure-reactivity relationship: an update. Atmos. Environ. 

29: 1685-1695. 1995. 

Lyman, WJ; Reehl, WF; Rosenblatt, DH. (1990) Selected nitroarenes. In: Handbook of chemical 

property estimation methods. Environmental behavior of organic compounds. Washington, DC: 

American Chemical Society, 4-8; 7-4–7-5; 8-13; 15-15–15-17. 

Morel, MC; Alers, I; Arce, R. (2006) Photochemical degradation of 1,6-and 1,8-dinitropyrene in 

solution. Polycyclic Aromatic Compounds 26:207–219. 

Neely, W.B. and Blau, G.E. Environmental exposure from chemicals. Volume 1. Boca Raton, 

FL: CRC Press. 1985. 

Pothuluri, JV; Sutherland, JB; Freeman, JP; et al. (1998) Fungal biotransformation of 6-

Nitrochrysene. Appl Environ Microbiol 64:3106–3109 

USEPA/OPPT. 1998. Technical Support Document for Determination of Bioaccumulation 

(BAF) and Bioconcentration (BCF) Values for Persistent Bioaccumulative Toxic (PBT) 

Chemicals and for Identification of PBT Chemicals. Jerry Smrchek, Ph.D., Biologist, Existing 

Chemicals Assessment Branch, Risk Assessment Division. September 1998. 

USEPA 2008. Estimation Programs Interface Suite (EPI Suite)TM. Available online at 

http://www.epa.gov/oppt/exposure/pubs/eipsuitedl.htm. (accessed July 24, 2009).