Diphenyl Carbonate Toxicity - Causes, Health Effects, and Treatment

Introduction

Diphenyl carbonate (DPC) is a chemical compound with the formula (C6H5O)2CO. It is a white-colored crystalline solid that can be dissolved in many organic solvents. DPC is used as an intermediate in the production of polycarbonate, a common plastic material. Additionally, other organic compounds including pharmaceuticals and pesticides are synthesized using it.

DPC is typically produced through the reaction of phenol and phosgene, a highly toxic gas. The synonyms of diphenyl carbonate are diphenyl ester and carbonic acid

How Is Diphenyl Carbonate Produced?

The phosgene and phenol are typically reacted together in a solvent, such as a dichloromethane or toluene, and the resultant mixture is stirred at a low temperature to control the reaction rate. The catalyst is added to the reaction mixture and is permitted for the reaction to finish. The resulting diphenyl carbonate can be isolated and purified by standard techniques, such as distillation or crystallization.

Alternative methods for the production of diphenyl carbonate include the transesterification of dimethyl carbonate with phenol and the reaction of carbon dioxide with phenol in the presence of a metal catalyst. However, the phosgene-based process is the most widely used method for the production of diphenyl carbonate on an industrial scale.

What Is Diphenyl Carbonate Toxicity?

Diphenyl carbonate is a chemical compound that is associated with potential health hazards, and exposure to high levels of this compound can be toxic. Diphenyl carbonate toxicity refers to the harmful effects that can result from exposure to this compound.

What Are the Causes of Diphenyl Carbonate Toxicity?

The reasons for diphenyl carbonate toxicity include:

1. Occupational Exposure: Workers in industries that use this compound, such as the pharmaceutical and chemical industries, are at risk of occupational exposure to diphenyl carbonate. Workers may inhale DPC vapors or come in contact with it through the skin or eyes, due to insufficient safety measures. All these routes of exposure may increase the chances of toxicity.

2. Environmental Exposure: Diphenyl carbonate-containing waste contaminates the soil and water if disposed of without following proper guidelines, leading to potential toxicity in the environment.

3. Accidental exposure: Accidental exposure can also occur due to spills or leaks during transportation, storage, or handling of the compound. Ingestion of this compound, even in small amounts, can cause toxicity.

What Are the Health Effects of Diphenyl Carbonate Toxicity?

The toxic effects of diphenyl carbonate toxicity can differ among persons depending on the duration, level of exposure, and route of exposure.

• Ingestion

  • If accidentally ingested, diphenyl carbonate can be harmful, and ingestion of even small amounts, such as fewer than 150 grams, may result in a fatality or serious health damage based on animal studies.

  • Nausea, vomiting, and stomach pain may be present if exposure occurs through ingestion. If large amounts of DPC are ingested, it can cause more severe symptoms such as unconsciousness and convulsions.

• Direct Contact

  • Direct contact with the eye can cause temporary discomforts such as tearing and conjunctival redness, along with slight abrasive damage. Sometimes it results in severe eye irritation and damage, leading to permanent eye injury or blindness.

  • Skin contact with diphenyl carbonate may lead to systemic effects due to absorption, and although it is not considered a skin irritant according to animal models, prolonged exposure can cause abrasive damage.

  • Molten material may cause burns, and it is not recommended to expose open cuts, abrasions, or irritated skin to this material. The material entering the bloodstream through cuts, abrasions, or lesions may cause systemic injury with harmful effects.

  • Before using the material, examining the skin and ensuring any external damage is adequately protected is essential.

• Inhalation

  • Some evidence suggests that the substance may cause respiratory irritation in certain individuals. This irritation can create further damage to the lungs.

  • Processing the material for extended periods or at high temperatures can generate highly irritating vapors that may cause red, itchy eyes, coughing, and a sore throat.

  • Individuals with impaired respiratory function, airway diseases, or conditions like emphysema or chronic bronchitis develop toxic effects earlier, as inhaling excessive concentrations of particulates can worsen the existing respiratory disabilities.

  • As the material is usually handled as a molten liquid, it poses a hazard of vapor exposure and requires workers to use thermal protection.

• Chronic Health Effects

  • The potential long-term health effects of this substance have raised concerns, particularly regarding its ability to cause cancer or mutations. However, a thorough evaluation cannot be made due to insufficient data.

  • Additionally, evidence suggests that inhaling the substance may cause a sensitization reaction in some individuals more often than in the general population. Similarly, there is limited evidence that skin contact with the substance may also cause a sensitization reaction in some individuals.

  • Prolonged exposure to high levels of dust-containing particles smaller than 0.5 microns can result in changes to lung function, leading to pneumoconiosis.

  • Sensitive individuals may experience allergic reactions due to chronic exposure.

  • Long-term exposure to this compound can cause neurological effects such as headaches, dizziness, and memory loss.

How to Diagnose Diphenyl Carbonate Toxicity?

Diphenyl carbonate toxicity can be diagnosed in the following ways:

• Medical History: A thorough medical history can help to identify affected individuals. The doctor may inquire about the person's occupation, hobbies, and any recent incidents of accidental exposure to toxic compounds.

• Physical Examination: During this examination signs of skin irritation or burns, respiratory distress, or neurological symptoms may be detected.

• Laboratory Tests: Laboratory tests may be conducted to confirm the toxicity. These may include blood tests, urine tests, or other specialized tests to detect the presence of DPC or its metabolites in the body.

• Imaging Tests: Imaging tests such as chest X-rays or CT (computed tomography) scans may be ordered to check for any respiratory or neurological damage.

What Is the Treatment for Diphenyl Carbonate Toxicity?

The diphenyl carbonate toxicity can be managed with the help of the following:

• Removal From Exposure: The first step in treating DPC toxicity is to remove the person from the source of exposure. This may involve evacuating the area if DPC has been spilled or leaked or removing the person from the workplace if the exposure occurred on the job.

• Decontamination: Decontamination of the skin or eyes may be necessary to remove any residual DPC. The affected area may need to be washed for at least 20 minutes with saline or water.

• Supportive Treatment: This basic treatment may be necessary to manage the symptoms of DPC toxicity. This may involve administering oxygen, providing breathing assistance, or treating skin burns or other injuries.

  • Check for airway blockage and use suction if necessary

  • Watch out for signs of respiratory insufficiency and provide assistance with ventilation if required

  • Administer oxygen using a non-rebreather mask at a flow rate of 10 to 15 L/min (liter per minute).

  • Give activated charcoal to remove the compound from the body if required.

• Medications: Medications may be used to treat specific symptoms of DPC toxicity. Anti-inflammatory drugs and pain relievers may be used to alleviate swelling, pain, and others. Use Proparacaine hydrochloride to help with eye irrigation.

• Hospitalization: Hospitalization helps to provide intensive care and monitoring in severe cases of toxicity.

Conclusion

Diphenyl carbonate is an important industrial chemical, but it is also associated with potential health and environmental hazards if it is not handled and disposed of properly. Proper safety protocols must be followed when handling and using this compound. Protective measures such as wearing appropriate personal protective equipment, using adequate ventilation, and practicing good hygiene can help to prevent exposure in most cases. If exposed accidentally, it is crucial to seek medical attention without delay.