How Benzene in Cigarette Smoke Can Hurt You

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Benzene is a colorless, flammable liquid naturally present in coal tar, crude oil, and as a byproduct of volcanic eruptions and forest fires.  It has a sweet smell and evaporates quickly when exposed to the air. 

Benzene is classified by the International Agency for Research on Cancer as a Group 1 human carcinogen.

Benzene is among the 20 most widely used chemicals in production in the United States today.

It's primarily used to make other chemicals, such as:

  • nylon
  • polystyrene
  • pesticides
  • pharmaceuticals
  • detergents
  • dyes
  • explosives
  • carpet glue, spray adhesive
  • furniture wax

Because benzene is a component of crude oil, it is also present in home heating oil and gasoline.

Auto exhaust is responsible for the majority of benzene in outdoor air.  Diesel exhaust also contains benzene. 

The amount of benzene in gasoline has been reduced in recent years following regulations set for MSAT (Mobile Source Air Toxics) by the Environment Protection Agency.  The amount of benzene emitted through vehicle exhaust and gas cans should be 61,000 tons less by 2030 due to MSAT restrictions. This will be due in part to newer vehicles that don't emit as many spent fuel toxins into the air. The amount of benzene in gasoline will have decreased by 38 percent overall as well.

Benzene in Cigarette Smoke

Benzene is a by-product of the combustion of tobacco in cigarettes.

Exposure to cigarette smoke accounts for roughly half of all human exposure to this toxin in the United States.

Benzene is extremely volatile. The primary method of exposure is through inhalation.

Cigarette smoke is also responsible for most of the benzene present in indoor environments.

Smokers and non-smokers alike are exposed to benzene when they breathe in secondhand smoke.

How Does Benzene Affect Human Health?

Long-term (a year or more) exposure to benzene can produce changes in the blood. It decreases red blood cells and damages bone marrow.  This puts people at risk for aplastic anemia  and excessive bleeding.

Benzene is associated with an increased risk of leukemia, specifically, acute myeloid leukemia.  There is concern that benzene may also contribute to acute and chronic lymphocytic leukemia, non-Hodgkin's lymphoma and multiple myeloma. 

Benzene exposure can weaken the immune system because it also damages white blood cells. This puts people at risk for more infections.

Other Effects of Exposure to Benzene

Although it's rare to encounter a high dose of benzene all at once, this kind of exposure through inhalation or ingestion damages the central nervous system and can lead to some dramatic symptoms:

  • paralysis
  • coma
  • convulsions
  • dizziness
  • sleepiness
  • rapid heart rate
  • tightness in the chest
  • tremors
  • rapid breathing

If you think you've been exposed to benzene in an enclosed space, get outside to fresh air immediately.

If the benzene was released outside, move as far away from the area as possible.

Remove all of your clothing and quickly wash your body with soap and water as soon as you are able to. 

If you swallowed benzene, do not try to induce vomiting or drink fluids.  Vomit could be sucked into the lungs and damage lung tissue.

Call 911 or seek medical care immediately.


Benzene is just one of hundreds of  poisonous and carcinogenic chemical compounds found in air tainted with cigarette smoke. Breathing in ETS threatens life for smokers and nonsmokers alike.

If you're still smoking, use the resources below to get started with a quit program that will help you overcome nicotine addiction once and for all.

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World Health Organization. Exposure to Benzene: A Major Public Health Concern. Accessed July, 2016.

U.S. National Library of Medicine. Benzene. Accessed July, 2016.

Department of Environmental Quality - State of Oregon. Air Toxics of Concern in Oregon. Accessed July, 2016.

Centers for Disease Control and Prevention. Facts about Benzene. Accessed July, 2016.

U.S. Environmental Protection Agency. Control of Hazardous Air Pollutants from Mobile Sources: Final Rule to Reduce Mobile Source Air Toxics. Accessed July, 2016.

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