E

Ethanol, Methanol, Tert-butyl Alcohol

CASRN 64-15-5, 67-56-1, 75-65-0

Physical Properties

Ethanol, methanol, and tert-butyl alcohol are all clear, colorless liquids. Tert-butyl alcohol can form crystals. Ethanol has a mild order, like wine or whiskey, methanol has an alcohol odor – slightly more pungent than ethanol, and tert-butyl alcohol has a camphor-like odor. All three compounds are very soluble in water. The odor threshold for ethanol is reported to be 10 part per million (ppm). The odor threshold for methanol is reported to be 100 ppm. The odor threshold for tert-butyl alcohol is about 75 ppm.

Uses

Most ethanol is used in alcoholic beverages in a variety of dilutions. Other uses for ethanol are as a solvent, in the manufacture of denatured alcohol, in pharmaceuticals, in perfumery, in organic synthesis, as an octane booster in gasoline, and as a significant portion in some automobile fuels. Methanol is used as an industrial solvent, as a raw material for making formaldehyde and methyl esters of organic and inorganic acids, as an antifreeze for automotive radiators and brakes, as an octane booster in gasoline, and as an extractant for animal and vegetable oils. Tert-butyl alcohol is use to separate water from substances, in the manufacture of flotation agents (for mining) and in flavors, as a solvent in paint removers, and as an octane booster in gasoline.

Sources of Exposure in Iowa

The general population is exposed to ethanol through the consumption of alcoholic beverages. Exposure to ethanol through inhalation and dermal contact will occur in workers at industries that manufacture ethanol. Exposure to ethanol will occur from exposure to gasoline that contains ethanol. Exposure to methanol will occur in workers in industries that manufacture and use methanol as a solvent. The general population may be exposed to small amounts of methanol in outside air, and in the food and water that they drink. The majority of exposure to tert-butyl alcohol will occur in industries that utilize it as a solvent or as a component in solvents.

Health Effects from Large Acute Exposures

The health effects from exposure to large short-term exposure to ethanol and other alcohols (methanol and tert-butyl alcohol) have been well-documented. Ethanol and other alcohols are central nervous system depressants and exposure to large amounts causes impaired judgment, decreased reaction time, confusion, stupor, coma, and possible death. Exposure to high levels of methanol can also cause partial to total blindness. Tert-butyl alcohol is more slowly metabolized than ethanol and methanol, so the health effects are more persistent.

Health Effects from Smaller Chronic Exposures

Chronic or long-term exposure to lower levels of ethanol and other alcohols can cause kidney, liver, and heart damage. Exposure to skin can cause redness and irritation. There is not enough information to classify ethanol, methanol, and tert-butyl alcohol as carcinogenic.

Protection from Exposure

Limiting the consumption of alcoholic beverages is the most effective method to be protected from exposure to ethanol and other alcohols. Respiratory protection and dermal protection should be worn when handling large amounts of alcohols in an industrial setting.

Ethylene

CASRN 75-85-1

Physical Properties

Ethylene is a colorless gas with a sweet odor. Ethylene is a highly flammable and non-corrosive gas. Ethylene has an odor threshold of 260 ppm (parts per million).

Uses

Ethylene is the most produced organic compound in the world. The principal industrial use of ethylene is as a "building block" for chemical raw materials which in turn are used to manufacture a large variety of substances and products. Some of the major chemicals and materials derived from ethylene are: vinyl chloride monomer or 1, 2-dichloroethane, styrene monomer, acetaldehyde, polyethylene, and ethylene oxide. In smaller quantities, ethylene is used as an anesthetic agent, as a refrigerant, to hasten fruit ripening, and as a welding gas.

Sources of Exposure in Iowa

The most common exposure to ethylene is within the workplace where ethylene is used to make other substances and chemicals. Manufacturers of styrene and polyethylene use ethylene and will be a source of exposure to ethylene. Since ethylene is a gas at room temperature, the most common route of exposure to ethylene is by inhalation.

Health Effects from Large Acute Exposures

Ethylene is an asphyxiate when the concentration within air is high enough. The potential for high concentrations of ethylene may exist within enclosed or confined spaces. Exposure to ethylene in large amounts within air would cause a lack of oxygen in the body that results in unconsciousness and may cause death if the concentration is high enough. Other health effects from exposure to large amounts of ethylene can cause drowsiness, dizziness, headaches, and confusion. Exposure to large amounts of ethylene has caused changes in metabolism and has caused temporary hypoglycemia.

Health Effects from Smaller Chronic Exposures

Long term or chronic exposure to ethylene has been associated with a decrease in blood pressure, slower pulse rate, changes in motor-visual response, and a decreased ability to control body temperature. Ethylene has not been classified as a human carcinogen.

Protection from Exposure

A person who works in an industry that manufacturers or uses ethylene should work in a well-ventilated area, or use respiratory protection when necessary.

Ethlylene Glycol

CASRN 107-21-1

Physical Properties

Ethylene glycol is a colorless, odorless liquid with a sweet taste that absorbs and dissolves readily within water. Ethylene glycol, by itself, evaporates into air very quickly, but will remain dissolved within water if it is present within a water solution.

Uses

Ethylene glycol is used to make antifreeze and de-icing solutions for cars, airplanes, and boats. It is an ingredient in hydraulic brake fluids and in inks used in stamp pads, ballpoint pens, and print shops. It is also used as a solvent in the paint and plastics industry, and is used to produce polyester fibers.

Sources of Exposure in Iowa

General population exposure to ethylene glycol mainly occurs through use of products such as antifreeze, de-icing solution, and hydraulic brake fluids. The amount of ethylene glycol within hydraulic brake fluids is 0.1%, so the potential for exposure to ethylene glycol is very small in this case. The source of exposure to larger amounts of ethylene glycol occurs from the use of de-icing fluids at airports or from storm water runoff from airports where ethylene glycol was used. People who work in industries that use ethylene glycol have the greatest potential for exposure.

Health Effects from Large Acute Exposures

Exposure to amounts of ethylene glycol in amounts from 5 to 50 fluid ounces through swallowing can cause death in humans. Antidotal treatment for ethylene glycol poisoning is successful, if treatment is received shortly after poisoning. When larger amounts of ethylene glycol are ingested adverse health impacts can include central nervous system depression, gastrointestinal upset, irregular heart rhythm, and the formation of crystals within the kidneys.

Health Effects from Smaller Chronic Exposures

A person’s health is not likely to be adversely impacted by the very small amounts of ethylene glycol that could be tasted or otherwise accidentally eaten (for example, by putting your fingers in your mouth after getting them wet with antifreeze). Studies on long term exposure to ethylene glycol in animals have shown adverse health impacts to the kidneys. There is no evidence that ethylene glycol causes cancer.

Protection from Exposure

Proper safety equipment should be used when handling ethylene glycol or potentially exposed to ethylene glycol in an industrial setting. Rubber gloves and chemical splash goggles should be worn to provide protection from exposure.