Pyromellitic dianhydride

H317: May cause an allergic skin reaction [Warning Sensitization, Skin]

H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]

H334: May cause allergy or asthma symptoms or breathing difficulties if inhaled [Danger Sensitization, respiratory]

P233, P260, P261, P264+P265, P271, P272, P280, P284, P302+P352, P304+P340, P305+P354+P338, P317, P321, P333+P317, P342+P316, P362+P364, P403, and P501 (click each P-code to see the statement)

H317 (100%): May cause an allergic skin reaction [Warning Sensitization, Skin]

H318 (100%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

H334 (100%): May cause allergy or asthma symptoms or breathing difficulties if inhaled [Danger Sensitization, respiratory]

Aggregated GHS information provided per 673 reports by companies from 4 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.

H315: Causes skin irritation [Warning Skin corrosion/irritation]

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

H360: May damage fertility or the unborn child [Danger Reproductive toxicity]

H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

H401: Toxic to aquatic life [Hazardous to the aquatic environment, acute hazard]

P203, P233, P260, P261, P264, P264+P265, P270, P271, P272, P273, P280, P284, P302+P352, P304+P340, P305+P354+P338, P317, P318, P319, P321, P332+P317, P333+P317, P342+P316, P362+P364, P403, P403+P233, P405, and P501 (click each P-code to see the statement)

P261, P264+P265, P272, P280, P302+P352, P305+P354+P338, P317, P321, P333+P317, P362+P364, and P501 (click each P-code to see the statement)

Fresh air, rest. Half-upright position. 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.

Rinse mouth. Do NOT induce vomiting.

Use water spray, powder, foam, carbon dioxide.

/To fight fire use:/ Powder, water spray, foam, carbon dioxide.

Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Wash away remainder with plenty of water.

Sweep spilled substance into containers; if appropriate, moisten first to prevent dusting. Wash away remainder with plenty of water. (Extra personal protection: P2 filter respirator for harmful particles.)

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.

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.

Dry. Well closed.

0.098 [mg/m3]

1.1 [mg/m3]

6.4 [mg/m3]

Evaporation at 20 °C is negligible; a harmful concentration of airborne particles can, however, be reached quickly when dispersed.

The substance is irritating to the eyes, skin and respiratory tract. Exposure at high levels could cause pulmonary haemorrhage.

Repeated or prolonged contact may cause skin sensitization. Repeated or prolonged inhalation may cause asthma.

Safety goggles, or eye protection in combination with breathing protection. Protective gloves. Protective clothing.

NO open flames.

PREVENT DISPERSION OF DUST!

Use local exhaust or breathing protection.

Protective gloves. Protective clothing.

Wear safety goggles or eye protection in combination with breathing protection.

Do not eat, drink, or smoke during work. Wash hands before eating.

Large Crystals; Dry Powder

White hygroscopic solid; [ICSC] White or off-white powder; [Alfa Aesar MSDS]

WHITE HYGROSCOPIC CRYSTALLINE POWDER WITH CHARACTERISTIC ODOUR.

White powder

397-400 °C

Soluble in some organic solvents

In water, 130 mg/L @ 25 °C /Estimated/

Solubility in water: reaction

1.68 g/cu cm

1.68 g/cm³

1.68 @25 °C

0.0000048 [mmHg]

4.8X10-6 mm Hg @ 25 °C /Estimated/

0.0000048 [mm Hg] @25 °C

log Kow = 2.14 /Estimated/

Henry's Law constant = 7.5X10-9 atm-cu m/mole @ 25 °C /Estimated/

Hydroxyl radical reaction rate constant = 2.9X10-13 cu cm/molecule-sec @ 25 °C /Estimated/

Boiling point

Chemical shift

Fusion temperature

Heat of sublimation

Lineshape

Melting temperature

Phase transition

Transition enthalpy

Vapor pressure

FCS -> FDA Cumulative Estimated Daily Intake (CEDI)

FCS -> FDA Inventory of Food Contact Substances Listed in 21 CFR

FCS -> FDA Inventory of Effective Food Contact Substance (FCS) Notifications

Plastics & Rubber -> Acid Anhydrides, Cyclic

The substance can be absorbed into the body by inhalation of its aerosol.

Cough. Sore throat. Wheezing. Shortness of breath.

Redness. Burning sensation.

Redness. Pain. Blurred vision.

Burning sensation.

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

Skin Sensitizer - An agent that can induce an allergic reaction in the skin.

Asthma - Reversible bronchoconstriction (narrowing of bronchioles) initiated by the inhalation of irritating or allergenic agents.

LCLo (rat) = 150 mg/m3/4hr

LD50 Guinea pig oral 1595 mg/kg

LD50 Mouse oral 2400 mg/kg

LD50 Rat oral 2250 mg/kg

Basic treatment: Establish a patent airway. 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 normal saline 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/

Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in respiratory arrest. 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. Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start an IV with D5W /SRP: "To keep open", minimal flow rate/. Use lactated Ringer's if signs of hypovolemia are present. Watch for signs of fluid overload. Consider drug therapy for pulmonary edema ... . 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/

/HUMAN EXPOSURE STUDIES/ ...Pyromellitic dianhydride... /has/ been reported to cause occupational immune lung disease (OILD).

/HUMAN EXPOSURE STUDIES/ The most common adverse health effects of the acid anhydrides are noncardiac pulmonary edema, immune sensitization, and irritation of mucous membranes and skin. Reports of the irritant effects and pulmonary edema have been extensive; some of the reports of pulmonary edema, pulmonary hemorrhage, and chemical pneumonitis may actually represent immune sensitization that was not evaluated. Immune sensitization, which has been studied only in the last 15 years, is probably the most important problem clinically. The first cases were probably reported in the 1940s, but there was no accompanying immunologic investigation. /Acid anhydrides/

/CASE REPORTS/ A 17-yr-old man was occupationally exposed to pyromellitic acid dianhydride dust during the production of epoxy resin in a chemical factory. He was clinically diagnosed as having acute hemorrhagic alveolitis associated with anemia. The serologic analysis revealed a high concentration of IgG antibodies against pyromellitic acid dianhydride-treated human serum albumin (PMDA-HSA). Immunoblotting with PMDA-treated human serum as antigen and the patient's serum as the first antibody showed that additional PMDA-modified serum proteins other than HSA were recognized by the patient's IgG antibodies in the higher mol. mass range (>67 kDa). No specific IgG could be detected against other anhydride conjugates (maleic acid, MA; phthalic acid, PA) with the exception of a reaction with the trimellitic acid anhydride-conjugated HSA (TMA-HSA). No specific IgE antibodies could be detected against any of the above mentioned antigens, but immunoblotting of the patient's serum indicated IgG4-type autoantibodies against in vitro PMDA-treated Ig molecules of normal serum proteins.

/CASE REPORTS/ Seven workers using an epoxy adhesive cured with pyromellitic dianhydride were studied. Workers both mixed and used the adhesive. Each completed a questionnaire about previous respiratory symptoms, family or personal history of atopy, smoking history and symptoms using the adhesive. FEV1 /(forced expiratory volume in 1 second)/ was measured as a base-line and after working with the adhesive. Skin tests to common allergens were performed on all subjects. Two subjects who stated they wheezed with adhesive had falls in FEV1 of 15% and 18% from base-line. Totally symptom-free subjects had falls of less than 4% from base-line or a rise in FEV1. There was no clear relationship between smoking habits or atopic state or skin rashes with resin and a fall in FEV1. There is no simple way to identify those at risk of developing wheeze. Care should be taken with epoxy adhesives to avoid sensitization and where it occurs a simple questionnaire would provide a screening method.

For more Human Toxicity Excerpts (Complete) data for PYROMELLITIC DIANHYDRIDE (7 total), please visit the HSDB record page.

/LABORATORY ANIMALS: Acute Exposure/ Poisoning /in animals/ is accompanied by CNS depression including behavioral changes (ataxia, somnolence, adynamia, muscle weakness, etc.). Death within the first three days.

/LABORATORY ANIMALS: Acute Exposure/ /1,2,4,5-Benzenetetracarboxylic, 1,2:4,5 dianhydride/ exhibits mild sensitizing properties on skin application of 0.2 mg/kg bw to guinea pigs.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ Female rats exposed to 4.4 and 8.8 mg/kg bw for 6 months developed changes in the activities of a number of enzymes (cholinesterase, AST and ALT, cytochrome oxidase, etc.). Gross pathology and histology changes were evident.

Pyromellitic dianhydride's production and use as a curing agent for epoxy resins and plasticizers may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 4.8X10-6 mm Hg at 25 °C indicates pyromellitic dianhydride will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase pyromellitic dianhydride will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 56 days. Pyromellitic dianhydride is a hygroscopic substance that undergoes hydrolysis when contacted by moist air resulting in the formation of pyromellitic acid. Particulate-phase pyromellitic dianhydride that has not reacted with moist air or hydroxyl radicals will be removed from the atmosphere by wet and dry deposition. If released to soil, pyromellitic dianhydride is expected to have moderate mobility based upon an estimated Koc of 178. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 7.5X10-9 atm-cu m/mole. If released into water, pyromellitic dianhydride is expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. No biodegradation data were located for pyromellitic dianhydride, and it is expected that hydrolysis in moist soil and water will be the dominant fate process for this compound. The estimated hydrolysis half-life of this compound at pH 8 is about 9 days. An estimated BCF of 9 suggests the potential for bioconcentration in aquatic organisms is low. Occupational exposure to pyromellitic dianhydride may occur through inhalation of dust and dermal contact with this compound at workplaces where pyromellitic dianhydride is produced or used. (SRC)

Pyromellitic dianhydride's production and use as a curing agent for epoxy resins and plasticizers(1) 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 178(SRC), determined from a structure estimation method(2), indicates that pyromellitic dianhydride is expected to have moderate mobility in soil(SRC). Volatilization of pyromellitic dianhydride from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 7.5X10-9 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Pyromellitic dianhydride is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 4.8X10-6 mm Hg(SRC), determined from a fragment constant method(4). No biodegradation data for pyromellitic dianhydride were located(SRC); however, this compound is expected to hydrolyze in moist environments including soils producing the monohydride and subsequently pyromellitic acid(5).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 178(SRC), determined from a structure estimation method(2), indicates that pyromellitic dianhydride is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 7.5X10-9 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of 9(SRC), from an estimated log Kow of 2.14(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). No biodegradation data for pyromellitic dianhydride were located(SRC); however, this compound is expected to hydrolyze in water producing the monohydride and subsequently pyromellitic acid(8). The hydrolysis half-life of pyromellitic dianhydride at pH 8 is estimated as about 9 days using an estimation method based on perturbed molecular orbital theory and linear free energy relationship (LFER) methods(9).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), pyromellitic dianhydride, which has an estimated vapor pressure of 4.8X10-6 mm Hg at 25 °C (SRC), determined from a fragment constant method(2), is expected to exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase pyromellitic dianhydride 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 56 days(SRC), calculated from its rate constant of 2.9X10-13 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Pyromellitic dianhydride is a hygroscopic substance that undergoes hydrolysis when contacted by moisture in the atmosphere resulting in the formation of pyromellitic acid(4). Unreacted particulate-phase pyromellitic dianhydride may be removed from the air by wet and dry deposition(SRC). Pyromellitic dianhydride absorbs light greater than 290 nm and is susceptible to direct photolysis in the environment(5), but the kinetics of this reaction are not known.

The rate constant for the vapor-phase reaction of pyromellitic dianhydride with photochemically-produced hydroxyl radicals has been estimated as 2.9X10-13 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 56 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Pyromellitic dianhydride is a hygroscopic substance that undergoes hydrolysis initially forming the monohydride and subsequently pyromellitic acid when contacted by moist air(2); however the rate of this reaction was not quantified. The second order base catalyzed rate constant of pyromellitic dianhydride was estimated as 0.868 l/mol-sec using an estimation method based on perturbed molecular orbital theory and linear free energy relationship (LFER) methods(3). This corresponds to a half-life of about 9 days at pH 8(SRC). Pyromellitic dianhydride absorbs light greater than 290 nm and is susceptible to direct photolysis in the environment(4), but the kinetics of this reaction are not known.

An estimated BCF of 9 was calculated for pyromellitic dianhydride(SRC), using an estimated log Kow of 2.14(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).

Using a structure estimation method based on molecular connectivity indices(1), the Koc for pyromellitic dianhydride can be estimated to be 178(SRC). According to a classification scheme(2), this estimated Koc value suggests that pyromellitic dianhydride is expected to have moderate mobility in soil(SRC).

The Henry's Law constant for pyromellitic dianhydride is estimated as 7.5X10-9 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that pyromellitic dianhydride is expected to be essentially nonvolatile from water surfaces(2). Pyromellitic dianhydride's Henry's Law constant indicates that volatilization from moist soil surfaces is not expected(SRC). Pyromellitic dianhydride is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 4.8X10-6 mm Hg(SRC), determined from a fragment constant method(3).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 286 workers (16 of these are female) are potentially exposed to pyromellitic dianhydride in the US(1). Occupational exposure to pyromellitic dianhydride may occur through inhalation of dust and dermal contact with this compound at workplaces where pyromellitic dianhydride is produced or used(SRC).

Pyromellitic dianhydride's production and use as a curing agent for epoxy resins and plasticizers may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 4.8X10-6 mm Hg at 25 °C indicates pyromellitic dianhydride will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase pyromellitic dianhydride will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 56 days. Pyromellitic dianhydride is a hygroscopic substance that undergoes hydrolysis when contacted by moist air resulting in the formation of pyromellitic acid. Particulate-phase pyromellitic dianhydride that has not reacted with moist air or hydroxyl radicals will be removed from the atmosphere by wet and dry deposition. If released to soil, pyromellitic dianhydride is expected to have moderate mobility based upon an estimated Koc of 178. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 7.5X10-9 atm-cu m/mole. If released into water, pyromellitic dianhydride is expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. No biodegradation data were located for pyromellitic dianhydride, and it is expected that hydrolysis in moist soil and water will be the dominant fate process for this compound. The estimated hydrolysis half-life of this compound at pH 8 is about 9 days. An estimated BCF of 9 suggests the potential for bioconcentration in aquatic organisms is low. Occupational exposure to pyromellitic dianhydride may occur through inhalation of dust and dermal contact with this compound at workplaces where pyromellitic dianhydride is produced or used. (SRC)

Pyromellitic dianhydride's production and use as a curing agent for epoxy resins and plasticizers(1) 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 178(SRC), determined from a structure estimation method(2), indicates that pyromellitic dianhydride is expected to have moderate mobility in soil(SRC). Volatilization of pyromellitic dianhydride from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 7.5X10-9 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Pyromellitic dianhydride is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 4.8X10-6 mm Hg(SRC), determined from a fragment constant method(4). No biodegradation data for pyromellitic dianhydride were located(SRC); however, this compound is expected to hydrolyze in moist environments including soils producing the monohydride and subsequently pyromellitic acid(5).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 178(SRC), determined from a structure estimation method(2), indicates that pyromellitic dianhydride is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 7.5X10-9 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of 9(SRC), from an estimated log Kow of 2.14(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). No biodegradation data for pyromellitic dianhydride were located(SRC); however, this compound is expected to hydrolyze in water producing the monohydride and subsequently pyromellitic acid(8). The hydrolysis half-life of pyromellitic dianhydride at pH 8 is estimated as about 9 days using an estimation method based on perturbed molecular orbital theory and linear free energy relationship (LFER) methods(9).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), pyromellitic dianhydride, which has an estimated vapor pressure of 4.8X10-6 mm Hg at 25 °C (SRC), determined from a fragment constant method(2), is expected to exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase pyromellitic dianhydride 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 56 days(SRC), calculated from its rate constant of 2.9X10-13 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Pyromellitic dianhydride is a hygroscopic substance that undergoes hydrolysis when contacted by moisture in the atmosphere resulting in the formation of pyromellitic acid(4). Unreacted particulate-phase pyromellitic dianhydride may be removed from the air by wet and dry deposition(SRC). Pyromellitic dianhydride absorbs light greater than 290 nm and is susceptible to direct photolysis in the environment(5), but the kinetics of this reaction are not known.

The rate constant for the vapor-phase reaction of pyromellitic dianhydride with photochemically-produced hydroxyl radicals has been estimated as 2.9X10-13 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 56 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Pyromellitic dianhydride is a hygroscopic substance that undergoes hydrolysis initially forming the monohydride and subsequently pyromellitic acid when contacted by moist air(2); however the rate of this reaction was not quantified. The second order base catalyzed rate constant of pyromellitic dianhydride was estimated as 0.868 l/mol-sec using an estimation method based on perturbed molecular orbital theory and linear free energy relationship (LFER) methods(3). This corresponds to a half-life of about 9 days at pH 8(SRC). Pyromellitic dianhydride absorbs light greater than 290 nm and is susceptible to direct photolysis in the environment(4), but the kinetics of this reaction are not known.

An estimated BCF of 9 was calculated for pyromellitic dianhydride(SRC), using an estimated log Kow of 2.14(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).

Using a structure estimation method based on molecular connectivity indices(1), the Koc for pyromellitic dianhydride can be estimated to be 178(SRC). According to a classification scheme(2), this estimated Koc value suggests that pyromellitic dianhydride is expected to have moderate mobility in soil(SRC).

The Henry's Law constant for pyromellitic dianhydride is estimated as 7.5X10-9 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that pyromellitic dianhydride is expected to be essentially nonvolatile from water surfaces(2). Pyromellitic dianhydride's Henry's Law constant indicates that volatilization from moist soil surfaces is not expected(SRC). Pyromellitic dianhydride is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 4.8X10-6 mm Hg(SRC), determined from a fragment constant method(3).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 286 workers (16 of these are female) are potentially exposed to pyromellitic dianhydride in the US(1). Occupational exposure to pyromellitic dianhydride may occur through inhalation of dust and dermal contact with this compound at workplaces where pyromellitic dianhydride is produced or used(SRC).

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.

Symbol: Xn; R: 41-42/43; S: (2)-22-24-26-37/39