Chem Explorers

Handling Acenaphthene Safely: Chemical Properties and Environmental Impact

Acenaphthene: An Insight into its Chemical PropertiesAcenaphthene is a colorless crystalline compound belonging to the family of polycyclic aromatic hydrocarbons (PAHs). It is composed of two fused aromatic rings with an ethylene bridge.

This compound is widely used in various applications of organic synthesis, and its molecular formula is C12H10. Acenaphthene has several forms, such as alpha and beta forms, which differ slightly in their physical and chemical properties.

Chemical Facts

Density and Melting Point

Acenaphthene has a density of 1.03 g/cm3 and a melting point of 93C. This compound is insoluble in water but soluble in many organic solvents, such as benzene, ether, and chloroform.

Because of its low polarity and high hydrophobicity, it can easily dissolve in non-polar solvents, such as hydrocarbons.

Vapor Pressure and Flash Point

Acenaphthene displays a low vapor pressure of 0.018 mmHg at 25C, indicating low volatility. It also has a high flash point of 130C, making it less prone to ignition.

Its low volatility and high flash point make it a safer alternative to other PAHs that are highly volatile and combustible.

Auto-Ignition Temperature and Half Life

The auto-ignition temperature is the lowest temperature at which a substance spontaneously ignites in air without an external source of ignition. Acenaphthene’s auto-ignition temperature is 530C, which is relatively high compared to other hydrocarbons.

Its half-life at pH 7 and 25C is 75 days, making it more stable than many other PAHs.

Uses of Acenaphthene

Acenaphthene is extensively used in organic synthesis as a starting material for the production of several industrial chemicals. It is also used as an intermediate in making dyes, resins, and pharmaceuticals.

This compound is also used to manufacture high-performance polymers and plastics, such as polyacrylonitrile and nylon. Acenaphthene is commonly used as an alternative to other highly carcinogenic PAHs, like benzene and naphthalene.

Toxicity of Acenaphthene

Acenaphthene toxicity can vary depending on its concentration and exposure duration. It has been shown to cause adverse effects on various organisms, including fish, algae, and microorganisms, when exposed to high concentrations.

Acenaphthene has also been linked to genotoxicity, mutagenicity, and carcinogenicity in some studies. However, the toxic effects of this compound can be minimized by handling it safely and avoiding exposure to it.


In conclusion, acenaphthene is an important precursor for several industrial chemicals and materials. It has a low volatility, high flash point, and high stability, making it a safer alternative to other PAHs. Despite its various applications, it is important to handle acenaphthene with care due to its potential toxic effects.

A comprehensive understanding of its chemical properties is necessary for safe handling and utilization in industrial and research applications.

Other Facts and Identification Features

Appearance and Constituent of PAH mixture

Acenaphthene is a white to colorless crystalline solid with a distinct camphor-like odor. It is one of the 16 PAH compounds identified by the Environmental Protection Agency (EPA) as priority pollutants due to their negative impacts on human health and the environment.

PAHs are commonly found in complex mixtures with other hydrocarbons, such as coal tar and crude oil. Acenaphthene constitutes approximately 8% of the total PAH mixture.

Component of Coal Tar and Alternative Names

One of the most common sources of acenaphthene is coal tar, which is a by-product of coal gasification and coke production. It is also found in other products of incomplete combustion such as diesel and gasoline exhaust fumes.

Acenaphthene is sometimes referred to as 1,2-Dihydroacenaphthylene or Acenaphthylene. These names are often used interchangeably with acenaphthene.

Fluorescence and Hydrogenated Form

Acenaphthene exhibits blue fluorescence when exposed to UV light and is often used as a fluorescent tracer in geological research. It also has a hydrogenated form, called tetrahydroacenaphthene or (Tetralin), which is produced by catalytic hydrogenation of acenaphthene in the presence of a metal catalyst.

Tetralin is widely used as a solvent in a variety of industrial applications, such as the production of adhesives, insulating materials, and motor oils.

Material Safety Data Sheet (MSDS)

Combustibility and Risks on Combustion

Acenaphthene is a combustible substance and can burn when exposed to heat, spark, or flame. It produces irritating smoke and fumes when burned, and the burning can release carbon monoxide gas, which is highly toxic.

Acenaphthene can also decompose in a fire, releasing toxic fumes, such as carbon dioxide and carbon monoxide. The risks of combustion can be minimized by storing and handling it in a well-ventilated area and away from sources of ignition.

Reaction with Strong Oxidants

Acenaphthene reacts with strong oxidants, such as nitric acid, sulfuric acid, and hydrogen peroxide, to form nitro and sulfonic acids. These reactions can be hazardous due to the exothermicity and corrosiveness of the reaction products.

Care must be taken when working with these chemicals, and proper safety measures should be put into place.

Human Exposure and Sources

Acenaphthene exposure can occur through inhalation, ingestion, or skin contact with contaminated soil, air, water, or food. Workers in the chemical industry, coal tar production, and petroleum refining are at the greatest risk of exposure.

Acenaphthene has been shown to cause skin, eye, and respiratory tract irritation, as well as reproductive and developmental toxicity in humans. Long-term exposure to acenaphthene is also linked to an increased risk of cancer.

In conclusion, acenaphthene is a commonly found PAH compound in coal tar and other products of incomplete combustion. It exhibits blue fluorescence when exposed to UV light and has a hydrogenated form, tetrahydroacenaphthene, which is widely used as a solvent.

Acenaphthene poses a risk of combustion, reacts with strong oxidants to form hazardous products, and can cause harmful health effects in humans when exposed. Proper safety measures and precautions should be followed to minimize the risks associated with handling and exposure to acenaphthene.

Health Implications on Exposure

Inhalation and Adverse Effects

Acenaphthene affects human health in various ways, including respiratory, cardiovascular, and endocrine systems. Inhalation of acenaphthene vapors can irritate the eyes, nose, throat, and lungs, causing coughing, wheezing, chest tightness, and shortness of breath.

Long-term exposure can lead to chronic bronchitis, emphysema, and reduced lung function. Acenaphthene can also cause allergies, triggering an immune response in sensitive individuals.

Cancer and Cardiovascular System

Acenaphthene is a recognized human carcinogen, categorized as Group B2 by the International Agency for Research on Cancer (IARC). Prolonged exposure to acenaphthene can increase the risk of developing cancer, particularly lung and skin cancer.

A study conducted by the National Toxicology Program (NTP) found that exposure to acenaphthene resulted in increased incidence of tumors in experimental animals. In addition, exposure to acenaphthene has also been linked to cardiovascular complications, such as hypertension, atherosclerosis, and stroke.

First Aid and Precautions for Operators

Inhalation and Skin Exposure

In cases of inhalation, move the affected person to fresh air and perform artificial respiration if necessary. Seek medical attention if the individual experiences shortness of breath or chest pain.

In cases of skin exposure, remove contaminated clothing and rinse the affected area with copious amounts of water. If skin irritation occurs, contact a physician and seek medical attention.

Eye and Ingestion Exposure

In cases of eye exposure, flush the affected eye with cold water for at least 15 minutes while holding the eyelids open. Seek medical attention if the eye irritation persists.

In case of ingestion, do not induce vomiting, and seek medical attention immediately. If the exposed person is unconscious, lie them on their side and loosen tight clothing.

Precautions for Handling and Fire Safety

Handling acenaphthene requires proper precautions to minimize the risk of injury and exposure. It is recommended to wear personal protective equipment, including gloves, goggles, and respiratory protection when handling this substance.

Keep the working area well-ventilated, and avoid exposure to heat, sparks, or flames. Adequate fire safety measures should also be implemented, including the use of fire extinguishers and avoiding the use of water to extinguish fires involving acenaphthene.

In conclusion, acenaphthene exposure can lead to respiratory and cardiovascular complications, and long-term exposure can increase the risk of cancer. Proper first aid measures should be taken in case of exposure, including inhalation, skin exposure, eye exposure, and ingestion.

Operators should take precautions when handling acenaphthene, including the use of personal protective equipment and adequate fire safety measures. It is crucial to follow proper safety guidelines and regulations to minimize the hazards associated with acenaphthene exposure.

Storage and Environmental Safeguards

Storage Precautions and Fire Extinguishers

Acenaphthene must be stored in a cool and dry place, away from direct sunlight, sources of heat, and ignition. It is recommended to store acenaphthene in a sealed container to prevent contamination and accidental spills.

Moreover, the storage area should be equipped with sufficient ventilation to prevent the buildup of vapors. It is crucial to mark the storage container with the product name, hazard warnings, and relevant regulatory information.

In case of a fire, foam, carbon dioxide, or dry powder extinguishers should be used. Water should not be used, as it may cause the fire to spread or generate toxic fumes.

Toxicity to Aquatic Organisms and Environmental Impact

Acenaphthene is a toxic substance that can have severe environmental impacts, particularly on aquatic organisms. The toxicity of acenaphthene to fish and other aquatic organisms depends on several factors, such as the species, temperature, pH, and water quality.

Exposure to acenaphthene can impair the growth, reproduction, and survival of aquatic flora and fauna. Even low concentrations of acenaphthene can have chronic impacts on aquatic ecosystems, causing long-term damage to the environment.

Moreover, acenaphthene can bioaccumulate in the food chain, posing risks to human health through consumption of contaminated seafood. To minimize environmental impacts, it is essential to handle and dispose of acenaphthene safely and responsibly.

Proper waste disposal methods should be followed, including treatment, incineration, or disposal in an appropriate landfill. It is crucial to check local regulations to ensure compliance with environmental standards and best practices.

Recycling or reuse of acenaphthene should be explored to minimize waste and reduce environmental impacts. Collaboration with regulatory bodies, industry associations, and other stakeholders can help mitigate potential risks and safeguard environmental health.


In conclusion, acenaphthene is a hazardous substance that poses several risks to human health and the environment. Proper storage, handling, and disposal of acenaphthene are crucial to minimize the risks and prevent potential accidents.

Operators should take the necessary precautions to avoid inhalation, skin contact, and ingestion of acenaphthene. First aid measures should be taken in case of exposure, and proper disposal methods should be followed.

It is also important to check local regulations and guidelines to ensure compliance with environmental standards. Collaboration among stakeholders is necessary to promote environmental health and mitigate the potential risks associated with acenaphthene exposure.

In summary, acenaphthene is a polycyclic aromatic hydrocarbon with various chemical properties and applications. It is important to understand its physical and chemical characteristics to handle it safely and utilize it effectively.

Acenaphthene’s combustion risks, toxicity, and environmental impacts emphasize the need for proper storage, handling, and disposal practices. The article highlights the importance of taking precautions to minimize health risks, such as wearing protective equipment and implementing fire safety measures.

In conclusion, a comprehensive understanding of acenaphthene is crucial for both operator safety and environmental protection. FAQs:


What is acenaphthene? Acenaphthene is a colorless crystalline compound that belongs to the family of polycyclic aromatic hydrocarbons (PAHs), commonly found in coal tar and incomplete combustion products.

2. What are the health risks of acenaphthene exposure?

Acenaphthene exposure can lead to respiratory and cardiovascular complications, allergies, and an increased risk of cancer, particularly lung and skin cancer. 3.

How should acenaphthene be stored to ensure safety? Acenaphthene should be stored in a cool, dry place away from heat, sources of ignition, and direct sunlight.

Sealed containers and proper ventilation are also necessary to prevent contamination and accidental spills. 4.

Can acenaphthene harm aquatic organisms? Yes, acenaphthene is toxic to aquatic organisms and can have severe environmental impacts.

It can impair growth, reproduction, and survival, and bioaccumulate in the food chain. 5.

What precautions should operators take when handling acenaphthene? Operators should wear personal protective equipment, such as gloves, goggles, and respiratory protection.

They should also follow fire safety measures, use appropriate fire extinguishers, and handle acenaphthene in a well-ventilated area.

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