Styrene is a colorless liquid that evaporates easily.

In its pure form, styrene has a sweet smell. Manufactured styrene may contain aldehydes, which give it a sharp, unpleasant odor.

•manufacturing

•consumer products

Large amounts of styrene are produced in the United States. Small amounts are produced naturally by plants, bacteria, and fungi. Styrene is also present in combustion products such as cigarette smoke and automobile exhaust.

Styrene is widely used to make plastics and rubber. Consumer products containing styrene include:

• packaging materials
• insulation for electrical uses (i.e., wiring and appliances)
• insulation for homes and other buildings
• fiberglass, plastic pipes, automobile parts
• drinking cups and other "food-use" items
• carpet backing

These products mainly contain styrene linked together in long chains (polystyrene). However, most of these products also contain a small amount of unlinked styrene.

Sources

Styrene can be found in air, soil, and water after release from the manufacture, use, and disposal of styrene-based products.

Break down

Air: Styrene is quickly broken down in the air, usually within 1–2 days.

Water and soil: Styrene evaporates from shallow soils and surface water. Styrene that remains in soil or water may be broken down by bacteria or other microorganisms.

Air

The primary way you can be exposed to styrene is by breathing air containing it. Releases of styrene into the air occur from:

• industries using or manufacturing styrene
• automobile exhaust
• cigarette smoke, and
• use of photocopiers

Rural or suburban air generally contains lower concentrations of styrene than urban air. Indoor air often contains higher levels of styrene than outdoor air.

• 0.06–4.6 parts per billion (ppb) in outdoor air
• 0.023–11.5 ppb in indoor air

Styrene is occasionally detected in groundwater, drinking water, or soil samples. Drinking water containing styrene or bathing in water containing styrene may expose you to low levels of this chemical.

Workplace air

A large number of workers are potentially exposed to styrene. The highest potential exposure occurs in the reinforced-plastics industry, where workers may be exposed to high air concentrations and also have dermal exposure to liquid styrene or resins.

Workers involved in styrene polymerization, rubber manufacturing, and styrene-polyester resin facilities and workers at photocopy centers may also be exposed to styrene.

Food

Low levels of styrene occur naturally in a variety of foods, such as fruits, vegetables, nuts, beverages, and meats. Small amounts of styrene can be transferred to food from styrene-based packaging material.

Enter your body

Inhalation: When you breathe air containing styrene, most of the styrene will rapidly enter your body through your lungs.

Ingestion: Styrene in food or water may also rapidly enter your body through the digestive tract.

Dermal contact: A very small amount may enter through your skin when you come into contact with liquids containing styrene.

Leave your body

Once in your body, styrene is broken down into other chemicals. Most of these other chemicals leave your body in the urine within few days.

Workers
•Inhalation

The most common health problems in workers exposed to styrene involve the nervous system. These health effects include changes in color vision, tiredness, feeling drunk, slowed reaction time, concentration problems, and balance problems.

The styrene concentrations that cause these effects are more than 1,000 times higher than the levels normally found in the environment.

Laboratory animals
•Inhalation

Hearing loss has been observed in animals exposed to very high concentrations of styrene.

Animal studies have shown that inhalation of styrene can result in changes in the lining of the nose and damage to the liver. However, animals may be more sensitive than humans to the nose and liver effects.

Laboratory animals
•Oral

Impaired learning has been observed in rats exposed to high doses of styrene.

Sperm damage has also been observed in rats exposed to high doses of styrene.

Cancer

The International Agency for Research on Cancer (IARC) has determined that styrene is a possible carcinogen.

Effects in children

There are no studies evaluating the effect of styrene exposure on children or immature animals. It is likely that children would have the same health effects as adults. We do not know whether children would be more sensitive than adults to the effects of styrene.

Birth defects

Studies in workers have examined whether styrene can cause birth defects or low birth weight; however, the results are inconclusive. No birth defects were observed in animal studies.

Breast milk

Nursing infants can be exposed to styrene from breast milk.

Tobacco smoke

Styrene is a component of tobacco smoke. Avoid smoking in enclosed spaces like inside the home or car in order to limit exposure to children and other family members.

Copier

Styrene is released during the use of home copiers. Families should use a copier only when needed and turn it off when finished. It is also important to keep the room with the copier well ventilated.

Detecting exposure

Styrene can be measured in blood, urine, and body tissues for a short time following exposure to moderate-to-high levels.

This should be done within a few hours after exposure occurs because these metabolites leave the body very quickly.

Measuring exposure

The presence of styrene breakdown products (metabolites) in urine might indicate that you were exposed to styrene; however, these metabolites can also form when you are exposed to other substances.

Measuring styrene metabolites in urine within 1 day of exposure allows medical personnel to estimate actual exposure level.

The detection of these metabolites in your urine cannot be used to predict the kind of health effects that might develop from that exposure.

Drinking water

The EPA has determined that exposure to styrene in drinking water at concentrations of 20 ppm for 1 day or 2 ppm for 10 days is not expected to cause any adverse effects in a child.

The EPA has determined that lifetime exposure to 0.1 ppm styrene in drinking water is not expected to cause any adverse effects.

Bottled water

The FDA has determined that the styrene concentration in bottled drinking water should not exceed 0.1 ppm.

Workplace air

OSHA set a legal limit of 100 ppm styrene in air averaged over an 8-hour work day.