What Is Benzene?
Benzene is a hydrocarbon classified as an aromatic hydrocarbon, and is the basis for this class of hydrocarbons.
All aromatics have a benzene ring, which is therefore also called an aromatic ring, has the formula C₆H₆.
It is an organic chemical substance that appears in the form of a colorless, volatile, flammable and sweet-smelling liquid. In nature, benzene is released by natural processes, such as volcanism and fires, but most of the release of benzene comes from human activity.
Environmental contamination by benzene can occur in the air, soil, and water. Once contaminated, soil and water are able to release benzene vapors into the air through a dynamic balance.
Unlike what occurs in those environments, benzene in the air is able to decompose in a few days, due to the climate and the concentration of other air pollutants.
Is benzene a solvent?
Benzene is soluble in alcohol, acetone, acetic acid, chloroform, carbon tetrachloride, diethyl ether. It is a widely used solvent and is present in gasoline, car emissions and cigarette smoke.
Is benzene acidic or basic?
According to Lewis’s theory of acids and bases, an acid accepts a pair of electrons and base donates the pair electrons, so benzene is a base because it donates a pair of electrons.
How do you make benzene?
As a constituent of petroleum, benzene is widely used in chemical laboratories, as a raw material in the chemical industries, in the petrochemical, oil refining, and steel companies.
It is closely linked to the processes of production, refinement, transport, and storage of oil, in the steel industries (through coke oven gas), the burning of fossil fuels and forests, industrial emissions, the evaporation of gasoline and cigarette smoke.
In addition, benzene is widely used in organic synthesis reactions in the chemical industry.
What products contain benzene?
Benzene is formed by natural processes and human activities.
We are going to list a bunch of processes, products, activities, occupations, industries, and locations where benzene can be found:
Natural processes that produce benzene
- Forest fires
Products containing benzene
- Paint, lacquer and varnish removers
- Industrial solvents
- Gasoline and other fuels
- Furniture wax
- Adhesives and coatings
- Industrial cleaners and formulations
Activities/uses involving benzene
- Exhaust emissions from motor vehicles
- Burning coal and oil
- Painting and lithography
- Dry cleaning
- Making chemicals used to make:
- Nylon and synthetic fibers
- Doing some types of:
- Pharmaceutical Medicines
- Agricultural chemicals (pesticides)
Industries that use benzene
- Petrochemical manufacturing
- Oil refinement
- Chemical manufacturer of coke and coal
- Manufacture of rubber tires
- Gasoline storage, shipping, and retail operations
- Plastics and rubber manufacturing
- Footwear manufacturing
Occupations/people who may be exposed to benzene
- Rubber workers
- Footwear manufacturers
- Laboratory technicians
- Petrol service station staff
Is Benzene Harmful?
Benzene is a known carcinogenic compound.
Studies show that people exposed to benzene can develop myeloid leukemia – a type of leukemia that is linked to malformation of red cells within the bone marrow.
The International Agency for Research on Cancer (IARC), the National Toxicological Program (NTP) and the Environmental Protection Agency (EPA) classify benzene as carcinogenic and there must be specific regulations for this compound. Besides, studies indicates benzene as an endocrine disruptor, which may alter the body’s natural form of hormonal regulation.
OSHA, the US federal agency responsible for health and safety regulation, limits exposure to benzene in the air, in most workplaces, to 1 ppm (part per million) during a workday.
When working with potentially higher exposure levels, OSHA requires employers to provide personal protective equipment, such as respirators.
The EPA limits the average percentage of benzene allowed in gasoline to 0.62% by volume (with a maximum of 1.3%).
Due to the high association of benzene with petroleum products, populations living around petrochemical industries are more exposed to benzene due to air pollution. Also because it is found in gasoline (derived from petroleum), benzene is released into the atmosphere by motor vehicles. Therefore, the greater the use of internal combustion vehicles, the greater the release of benzene into the atmosphere.
Usually, its manifestations occur up to 24 hours after contact with the fuel, as it causes toxic effects to the central nervous system; the symptoms are
- acceleration of the heartbeat,
- difficulty breathing,
- irritation of the ocular and respiratory mucous membranes, which can cause pulmonary edema (swelling).
Anemia, excessive bleeding (from the nose, for example) and a fall in the immune system increasing the chances of infections and the development of blood cancers of various types, such as leukemia, in addition to the suspicion of relationships with other tumors.
Changes in the state of consciousness and excitement followed by drowsiness are related to the amount absorbed.
The most common complaints from gas station workers are dizziness, headaches, nausea, dry mouth, and irritated eyes.
Benzene in Water
Benzene enters the water as discharge from industrial factories or leaching from landfills and gas storage tanks. For public water supply, the World Health Organization (WHO) establishes a limit of 10 parts per billion (ppb). In the United States, this limit is 5 ppb, and in the European Union, it is 1 ppb. In Brazil, Ordinance 2914/2011 set a limit value of 5 µg / L (microgram per liter).
Does the EPA Regulate Benzene in Water?
The EPA has set the maximum contaminant level goals (MCLG) to zero and the maximum contaminant level (MCL) at 5 parts per billion to protect consumers served by public water systems from the effects of long-term, chronic exposure to benzene. States may set more stringent drinking water MCLGs and MCLs for benzene than the EPA.
Benzene Removal From Drinking Water
Systems and cartridges that contain active carbon are the most effective treatment for the home.
- Reverse Osmosis Under sink water filters countertop water filters
- Whole house water filters
- Everpure systems and cartridges
- Carbon block cartridges
- Granulated activated carbon cartridges
- Aries filer works arsenic removal cartridges