4-Nitro-1,1'-biphenyl

H350: May cause cancer [Danger Carcinogenicity]

H411: Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P203, P273, P280, P318, P391, P405, and P501 (click each P-code to see the statement)

H350 (100%): May cause cancer [Danger Carcinogenicity]

H411 (100%): Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

Aggregated GHS information provided per 45 reports by companies from 2 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.

P203, P280, P318, P405, and P501 (click each P-code to see the statement)

Fresh air, rest. Refer for medical attention.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

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

Rinse mouth. Refer for medical attention .

Excerpt from NIOSH Pocket Guide for 4-Nitrobiphenyl:

Eye: IRRIGATE IMMEDIATELY - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: SOAP WASH IMMEDIATELY - If this chemical contacts the skin, immediately wash the contaminated skin with soap and water. If this chemical penetrates the clothing, immediately remove the clothing, wash the skin with soap and water, and get medical attention promptly.

Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible.

Swallow: MEDICAL ATTENTION IMMEDIATELY - If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2024)

(General first aid procedures)

Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: Soap wash immediately - If this chemical contacts the skin, immediately wash the contaminated skin with soap and water. If this chemical penetrates the clothing, immediately remove the clothing, wash the skin with soap and water, and get medical attention promptly.

Breathing: Respiratory support

Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately.

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

SMALL FIRE: Dry chemical, CO2 or water spray.

LARGE FIRE: Dry chemical, CO2, alcohol-resistant foam or water spray. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. (ERG, 2024)

Use water spray.

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Sweep spilled substance into covered sealable containers. Carefully collect remainder. Then store and dispose of according to local regulations.

RESEARCH PROGRAM WAS CONDUCTED TO DETERMINE THE CAPABILITY OF BIOL TREATMENT AND ACTIVATED CARBON ADSORPTION TO REMOVE CHEM CARCINOGENS FROM WATER AND WASTEWATER. CMPD STUDIED INCL 4-NITROBIPHENYL. ALL CMPD TESTED EXHIBITED SOME DEG OF BIOL DEGRADATION. CARBON ADSORPTION WAS ALSO EFFECTIVE IN REMOVING THE CMPD FROM AQ SOLN.

The worker should immediately wash the skin when it becomes contaminated.

Work clothing that becomes wet or significantly contaminated should be removed or replaced.

The worker should wash daily at the end of each work shift.

Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises.

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.

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2024)

Separated from strong reducing agents. Well closed.

6.7 [mg/m3]

74 [mg/m3]

440 [mg/m3]

Ca See Appendix A

[1910.1003] See Appendix B

A potential occupational carcinogen. (NIOSH, 2024)

NIOSH has recommended that 4-nitrobiphenyl be treated as a potential human carcinogen.

Ca [N.D.]

See: IDLH INDEX

Exposure by routes should be carefully controlled to levels as low as possible. /4-Nitrodiphenyl/

A2; Suspected human carcinogen; skin notation. /4-Nitrodiphenyl/

(skin); A2 (suspected human carcinogen).

Exposure by all routes should be carefully controlled to levels as low as possible. [1992]

skin absorption (H); carcinogen category: 2

A harmful concentration of airborne particles can be reached quickly when dispersed, especially if powdered.

The substance is irritating to the eyes.

This substance is probably carcinogenic to humans.

Excerpt from NIOSH Pocket Guide for 4-Nitrobiphenyl:

Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact.

Wash skin:

• WHEN CONTAMINATED - The worker should immediately wash the skin when it becomes contaminated.

• DAILY - The worker should wash daily at the end of each work shift, and prior to eating, drinking, smoking, etc.

Remove: WHEN WET OR CONTAMINATED - Work clothing that becomes wet or significantly contaminated should be removed and replaced.

Change: DAILY - Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises.

Provide:

• EYEWASH - Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substances; this is irrespective of the recommendation involving the wearing of eye protection.

• QUICK DRENCH - Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] (NIOSH, 2024)

Wear appropriate personal protective clothing to prevent skin contact.

Wear appropriate eye protection to prevent eye contact.

Eyewash fountains should be provided in areas where there is any possbility that workers could be exposed to the substance; this is irrespective of the recommendation involving the wearing of eye protection.

Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.]

For more Personal Protective Equipment (PPE) (Complete) data for P-NITROBIPHENYL (6 total), please visit the HSDB record page.

(See OSHA respirator requirements for selected chemicals)

At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration:

(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode

(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus

(APF = 50) Any air-purifying, full-facepiece respirator with an N100, R100, or P100 filter.

Click here for information on selection of N, R, or P filters. 

Any appropriate escape-type, self-contained breathing apparatus

4-nitrobiphenyl is a white to yellow needle-like crystalline solid with a sweetish odor. (NIOSH, 2024)

White to yellow, needle-like, crystalline solid with a sweetish odor; [NIOSH]

WHITE-TO-YELLOW CRYSTALS WITH CHARACTERISTIC ODOUR.

White to yellow, needle-like, crystalline solid with a sweetish odor.

YELLOW NEEDLES FROM ALC

WHITE NEEDLES

White to yellow, needle-like, crystalline solid.

SWEETISH ODOR

Sweetish odor.

644 °F at 760 mmHg (NIOSH, 2024)

340 °C @ 760 MM HG

340 °C @760 [mm Hg]

237 °F (NIOSH, 2024)

290 °F (NIOSH, 2024)

143 °C c.c.

Insoluble (NIOSH, 2024)

SOL IN ETHER, BENZENE, CHLOROFORM, ACETIC ACID

SLIGHTLY SOL IN COLD ALC

Solubility in water: very poor

Insoluble

When heated to decomp it emits toxic fumes of /nitrogen oxides/.

UV: 373 (Sadtler Research Laboratories Spectral Collection) /Biphenyl, 2-nitro/

UV: 6834 (Sadtler Research Laboratories Spectral Collection) /Biphenyl, 3-nitro/

Angular frequency

Chemical structure

Clearing parameter

Crystal structure

Crystal-to-crystal transition

External quantum efficiency

Formula unit

Liquid crystalline phase

Luminescence

Luminescence emission linewidth

Melting temperature

Melting transition

Polarization degree

Solid-to-solid transition

Space group

Transition pressure

Unit cell

Insoluble in water.

Hydrocarbons, Aromatic

Nitro, Nitroso, Nitrate, and Nitrite Compounds, Organic

4-NITROBIPHENYL is incompatible with the following: Strong reducers (NIOSH, 2024).

Strong reducers.

Strong reducers

No data are available in humans. Inadequate evidence of carcinogenicity in animals. OVERALL EVALUATION: Group 3: The agent is not classifiable as to its carcinogenicity to humans.

A2; Suspected human carcinogen. /4-Nitrodiphenyl/

4-Nitrobiphenyl

Group 3: Not classifiable as to its carcinogenicity to humans

Volume 4: (1974) Some Aromatic Amines, Hydrazine and Related Substances, N-Nitroso Compounds and Miscellaneous Alkylating Agents

Volume Sup 7: Overall Evaluations of Carcinogenicity: An Updating of IARC Monographs Volumes 1 to 42, 1987; 440 pages; ISBN 92-832-1411-0 (out of print)

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

inhalation, skin absorption, ingestion, skin and/or eye contact

See Effects of long-term or repeated exposure.

MAY BE ABSORBED!

Redness.

headache, drowsiness, dizziness; dyspnea (breathing difficulty); ataxia, lassitude (weakness, exhaustion); methemoglobinemia; urinary burning; acute hemorrhagic cystitis; [potential occupational carcinogen]

Bladder, blood

[in animals: bladder tumors]

ACGIH Carcinogen - Suspected Human.

LD50 Rabbit oral 1.97 g/kg

LD50 Rat oral 2.23 g/kg

THERE ARE NO DATA ON CARCINOGENICITY OF 4-NITROBIPHENYL IN MAN. HOWEVER, IT HAS BEEN USED IN PRODN OF 4-AMINOBIPHENYL, WHICH IS RECOGNIZED HUMAN BLADDER CARCINOGEN.

SUMMARY TOXICITY STATEMENT: /ACUTE/ ... MODERATE VIA ORAL ROUTE. MODERATE= MAY CAUSE REVERSIBLE OR IRREVERSIBLE CHANGES ... /TO EXPOSED TISSUE/, NOT NECESSARILY SEVERE ENOUGH TO CAUSE SERIOUS PHYSICAL IMPAIRMENT OR THREATEN LIFE.

THE INTERNATIONAL AGENCY FOR RESEARCH ON CANCER WORKING GROUP ON THE EVALUATION OF THE CARCINOGENIC RISK OF CHEMICALS TO MAN FOUND NO REPORTS ON CARCINOGENICITY OF 4-NITROBIPHENYL TO MAN. THE GROUP CONCLUDED THAT IT IS NOT POSSIBLE TO SEPARATE THE EXPOSURES TO 4-NITROBIPHENYL FROM EXPOSURES TO 4-AMINOBIPHENYL BECAUSE THE FORMER IS CONVERTED TO THE LATTER BY REDUCTION.

... CARCINOMAS OF BLADDER EPITHELIUM /WERE INDUCED/ IN 2/4 FEMALE MONGREL DOGS IN 33 MO BY FEEDING DOSE OF 300 MG 4-NITROBIPHENYL BY CAPSULE 3 TIMES/WK FOR LIFE (MAX TOTAL DOSE, APPROX 10 G/KG BODY WT). ... TOTAL DOSE OF 0.77 G/KG BODY WT WAS NOT EFFECTIVE IN INDUCING ... TUMORS IN 6 DOGS WITHIN 3 YR ... .

LIVER POST-MITOCHONDRIAL SUPERNATANTS FROM 10 DECEASED HUMANS USED FOR METABOLIC ACTIVATION OF CARCINOGENS IN AMES QUANTITATIVE MUTAGENICITY TEST USING SALMONELLA TYPHIMURIUM TA 100. 4-NITROBIPHENYL TESTED POSITIVE IN MOST SAMPLES.

THE EFFECT OF OZONATION ON THE MUTAGENICITY OF MUTAGENS AND(OR) CARCINOGENS WAS EVALUATED BY THE SALMONELLA/MICROSOME ASSAY. THE MUTAGENICITY OF POLYCYCLIC AROMATIC HYDROCARBONS AND AROMATIC AMINES WAS INACTIVATED BY OZONE TREATMENT, WHILE ALKYLATING AGENTS, NITRO AROMATICS, AND NITROSO COMPOUNDS WERE NOT AFFECTED. /NITRO AROMATICS/

In order to elucidate the mechanisms of mutagenic activation of nitroarenes, the mutagenic potency of 18 kinds of nitroarenes including nitrated biphenyl was tested on Salmonella typhimurium TA98 in the absence and presence of S9 mix. The mutagenicity of 4-nitrobiphenyl was enhanced by the addition of S9.

The substance is toxic to aquatic organisms. The substance may cause long-term effects in the aquatic environment.

p-Nitrobiphenyl does not appear to be manufactured, imported, used or sold on a commercial-scale in the US at the present time. No data are available to suggest that it is inadvertently formed during any commercial process or in the environment. p-Nitrobiphenyl was formerly used in the manufacture of 4-diphenylamine. Release to the environment may be restricted to leakages from prior disposals of hazardous wastes. If released to soil or water, biodegradation may be the major degradation process. A single biodegradation study has shown that p-nitrobiphenyl is significantly biodegradable with rapid microbial adaptation. Photodegradation may occur in water, in air, or on soil surfaces exposed to sunlight; however, kinetic rate data pertaining to environmental photolysis are not available to predict its relative significance. Estimated Koc values of 2680-3360 indicate that leaching in soil should not be important; in addition, some partitioning from the water column to aquatic sediments and suspended material may occur. If released to air, p-nitrobiphenyl will react in the vapor-phase with photochemically produced hydroxyl radicals at an estimated half-life rate of 6.8 days in an average atmosphere. Human exposure to p-nitrobiphenyl may be possible through contact with hazardous waste which was disposed of in past years. (SRC)

No data are currently available to suggest that p-nitrobiphenyl is currently manufactured, imported, used or sold on a commercial-scale in the United States. No data are available to suggest that p-nitrobiphenyl is inadvertently formed during any commercial process or in the environment. (SRC)

TERRESTRIAL FATE: The important p-nitrobiphenyl degradation process in soil may be biodegradation. A single biodegradation study has shown that p-nitrobiphenyl is biodegradable with rapid microbial adaptation. Estimated Koc values of 2680-3360 indicate that significant leaching should not occur in most types of soil. Photodegradation on soil surfaces exposed to sunlight may be possible. (SRC)

AQUATIC FATE: The important p-nitrobiphenyl degradation processes in water may be biodegradation and photolysis. A single biodegradation study has shown that p-nitrobiphenyl is significantly biodegradable with rapid microbial adaptation. p-Nitrobiphenyl has also been shown to photodegrade rapidly when diethylamine solutions are exposed to uv light above 290 nm. Photolysis in water may be important; however, kinetic rate data pertaining to environmental photolysis are not available to predict its relative significance. Estimated Koc values of 2680-3360 indicate that some partitioning from the water column to sediments and suspended material may occur. Moderate bioconcentration may be possible. Aquatic volatilization is expected to be relatively slow in comparison to other fate processes. Aquatic hydrolysis is not expected to be important. (SRC)

ATMOSPHERIC FATE: Based upon its chemical structure, p-nitrobiphenyl is expected to exist primarily in the vapor-phase in the ambient atmosphere, although a small percentage may be associated with the particulate-phase. Vapor-phase p-nitrobiphenyl is degraded in the ambient atmosphere by reaction with photochemically produced hydroxyl radicals. Degradation via direct photolysis may also be important; however, kinetic rate data pertaining to environmental photolysis are not available to predict its relative significance. (SRC)

p-Nitrobiphenyl exhibited fast biodegradation with rapid adaptation using a static-culture screening procedure with a settled domestic wastewater microbial inocula(1); degradation was determined to be 97.5% after 7 days of incubation(1).

The rate constant for the gas-phase reaction between p-nitrobiphenyl and hydroxyl radicals can be estimated to be 2.36X10-12 cu cm/molecule-sec at 25 °C which corresponds to a half-life of about 6.8 days in an average atmosphere containing 5X10+5 OH radicals/cu cm(1,SRC). p-Nitrobiphenyl has a uv absorption max at 295 nm(2) which suggests a potential for direct photolysis in the environment(SRC). Exposure of p-nitrobiphenyl (6.7 g/L) in a diethylamine solvent to uv irradiation above 290 nm for 3 hr resulted in 99% degradation(3); the degradation products were primarily azo aromatics(3). Aromatic nitro compounds are generally resistant to hydrolysis in water at pH 5-9(4); therefore, p-nitrobiphenyl is not expected to hydrolyze in the environment(SRC).

Based upon an estimated log Kow of 3.77(1), the BCF for p-nitrobiphenyl can be estimated to be 432 from a recommended regression equation(2,SRC). This estimated BCF value suggests that moderate bioconcentration may occur(SRC).

Based upon an estimated log Kow of 3.77(1), the Koc for p-nitrobiphenyl can be estimated to range from 2680 to 3360 using various regression-derived equations(2,SRC). These Koc estimates indicate very low soil mobility(3).

The Henry's Law Constant for p-nitrobiphenyl can be estimated to be 3.54X10-6 atm-cu m/mole at 25 °C using a structure estimation method(1,SRC). This value of Henry's Law Constant indicates slow volatilization from environmental waters, although volatilization from shallow rivers may have some significance(2). The volatilization half-life from a model river (1 meter deep flowing 1 m/sec with a wind speed of 3 m/sec) has been estimated to be 14.8 days(2,SRC); however, this estimation neglects the potentially significant effect of adsorption(SRC). The volatilization half-life from an environmental pond, which considers the effect of adsorption, can be estimated to be 1453 days(3,SRC); if parameters are introduced into the pond model to exclude the adsorption effects of p-nitrobiphenyl's log Kow of 3.77, the volatilization half-life is reduced to 160 days(SRC).

p-Nitrobiphenyl was analyzed for, but not detected (detection limit 0.68-3.2 ug/g), in particulate material collected from the exhaust of a heavy-duty diesel engine(1).

No data are currently available to suggest that p-nitrobiphenyl is currently manufactured, imported, used or sold on a commercial-scale in the United States. p-Nitrobiphenyl was formerly used in the manufacture of 4-diphenylamine(1). No data are available to suggest that p-nitrobiphenyl is inadvertently formed during any commercial process or in the environment. Therefore, exposure to the general population is not likely to occur. Exposure may be possible through contact with hazardous waste which was disposed of in past years. Laboratory workers handling reagent grades of p-nitrobiphenyl may be subject to exposure through dermal contact or inhalation(SRC).

The substance is toxic to aquatic organisms. The substance may cause long-term effects in the aquatic environment.

p-Nitrobiphenyl does not appear to be manufactured, imported, used or sold on a commercial-scale in the US at the present time. No data are available to suggest that it is inadvertently formed during any commercial process or in the environment. p-Nitrobiphenyl was formerly used in the manufacture of 4-diphenylamine. Release to the environment may be restricted to leakages from prior disposals of hazardous wastes. If released to soil or water, biodegradation may be the major degradation process. A single biodegradation study has shown that p-nitrobiphenyl is significantly biodegradable with rapid microbial adaptation. Photodegradation may occur in water, in air, or on soil surfaces exposed to sunlight; however, kinetic rate data pertaining to environmental photolysis are not available to predict its relative significance. Estimated Koc values of 2680-3360 indicate that leaching in soil should not be important; in addition, some partitioning from the water column to aquatic sediments and suspended material may occur. If released to air, p-nitrobiphenyl will react in the vapor-phase with photochemically produced hydroxyl radicals at an estimated half-life rate of 6.8 days in an average atmosphere. Human exposure to p-nitrobiphenyl may be possible through contact with hazardous waste which was disposed of in past years. (SRC)

No data are currently available to suggest that p-nitrobiphenyl is currently manufactured, imported, used or sold on a commercial-scale in the United States. No data are available to suggest that p-nitrobiphenyl is inadvertently formed during any commercial process or in the environment. (SRC)

TERRESTRIAL FATE: The important p-nitrobiphenyl degradation process in soil may be biodegradation. A single biodegradation study has shown that p-nitrobiphenyl is biodegradable with rapid microbial adaptation. Estimated Koc values of 2680-3360 indicate that significant leaching should not occur in most types of soil. Photodegradation on soil surfaces exposed to sunlight may be possible. (SRC)

AQUATIC FATE: The important p-nitrobiphenyl degradation processes in water may be biodegradation and photolysis. A single biodegradation study has shown that p-nitrobiphenyl is significantly biodegradable with rapid microbial adaptation. p-Nitrobiphenyl has also been shown to photodegrade rapidly when diethylamine solutions are exposed to uv light above 290 nm. Photolysis in water may be important; however, kinetic rate data pertaining to environmental photolysis are not available to predict its relative significance. Estimated Koc values of 2680-3360 indicate that some partitioning from the water column to sediments and suspended material may occur. Moderate bioconcentration may be possible. Aquatic volatilization is expected to be relatively slow in comparison to other fate processes. Aquatic hydrolysis is not expected to be important. (SRC)

ATMOSPHERIC FATE: Based upon its chemical structure, p-nitrobiphenyl is expected to exist primarily in the vapor-phase in the ambient atmosphere, although a small percentage may be associated with the particulate-phase. Vapor-phase p-nitrobiphenyl is degraded in the ambient atmosphere by reaction with photochemically produced hydroxyl radicals. Degradation via direct photolysis may also be important; however, kinetic rate data pertaining to environmental photolysis are not available to predict its relative significance. (SRC)

p-Nitrobiphenyl exhibited fast biodegradation with rapid adaptation using a static-culture screening procedure with a settled domestic wastewater microbial inocula(1); degradation was determined to be 97.5% after 7 days of incubation(1).

The rate constant for the gas-phase reaction between p-nitrobiphenyl and hydroxyl radicals can be estimated to be 2.36X10-12 cu cm/molecule-sec at 25 °C which corresponds to a half-life of about 6.8 days in an average atmosphere containing 5X10+5 OH radicals/cu cm(1,SRC). p-Nitrobiphenyl has a uv absorption max at 295 nm(2) which suggests a potential for direct photolysis in the environment(SRC). Exposure of p-nitrobiphenyl (6.7 g/L) in a diethylamine solvent to uv irradiation above 290 nm for 3 hr resulted in 99% degradation(3); the degradation products were primarily azo aromatics(3). Aromatic nitro compounds are generally resistant to hydrolysis in water at pH 5-9(4); therefore, p-nitrobiphenyl is not expected to hydrolyze in the environment(SRC).

Based upon an estimated log Kow of 3.77(1), the BCF for p-nitrobiphenyl can be estimated to be 432 from a recommended regression equation(2,SRC). This estimated BCF value suggests that moderate bioconcentration may occur(SRC).

Based upon an estimated log Kow of 3.77(1), the Koc for p-nitrobiphenyl can be estimated to range from 2680 to 3360 using various regression-derived equations(2,SRC). These Koc estimates indicate very low soil mobility(3).

The Henry's Law Constant for p-nitrobiphenyl can be estimated to be 3.54X10-6 atm-cu m/mole at 25 °C using a structure estimation method(1,SRC). This value of Henry's Law Constant indicates slow volatilization from environmental waters, although volatilization from shallow rivers may have some significance(2). The volatilization half-life from a model river (1 meter deep flowing 1 m/sec with a wind speed of 3 m/sec) has been estimated to be 14.8 days(2,SRC); however, this estimation neglects the potentially significant effect of adsorption(SRC). The volatilization half-life from an environmental pond, which considers the effect of adsorption, can be estimated to be 1453 days(3,SRC); if parameters are introduced into the pond model to exclude the adsorption effects of p-nitrobiphenyl's log Kow of 3.77, the volatilization half-life is reduced to 160 days(SRC).

p-Nitrobiphenyl was analyzed for, but not detected (detection limit 0.68-3.2 ug/g), in particulate material collected from the exhaust of a heavy-duty diesel engine(1).

No data are currently available to suggest that p-nitrobiphenyl is currently manufactured, imported, used or sold on a commercial-scale in the United States. p-Nitrobiphenyl was formerly used in the manufacture of 4-diphenylamine(1). No data are available to suggest that p-nitrobiphenyl is inadvertently formed during any commercial process or in the environment. Therefore, exposure to the general population is not likely to occur. Exposure may be possible through contact with hazardous waste which was disposed of in past years. Laboratory workers handling reagent grades of p-nitrobiphenyl may be subject to exposure through dermal contact or inhalation(SRC).

Symbol: T, N; R: 45-51/53; S: 53-45-61