People commonly use rubbing alcohol as a disinfectant for minor cuts and scrapes. The two most common forms of rubbing alcohol are ethyl alcohol and isopropyl alcohol. Both types are extremely toxic in their concentrated forms. Because most alcoholic drinks contain ethanol, rubbing alcohol made from ethanol usually contains additives such as sucrose octaacetate and denatonium benzoate to prevent people from drinking the alcohol for pleasure.
Isopropyl Alcohol Toxicity
Isopropyl alcohol, also called isopropanol, poses many risks to human beings. Inhaled fumes can cause respiratory tract irritation at low concentrations. At higher concentrations, the fumes can affect you like a narcotic, causing drowsiness, dizziness, loss of balance, headache, unconsciousness and even death. Ingestion of isopropanol can cause unconsciousness and death as well.
The approximate lethal dose of 90 to 100 percent isopropanol for human adults is only 250 millilters or about 8 ounces. While not fatal, ingesting smaller amounts can cause gastrointestinal problems, including cramps, pain, vomiting and diarrhea. Additionally, isopropanol vapors can irritate the eyes and splashes to the eyes can even burn your corneas.
Even though you may be accustomed to rubbing isopropyl alcohol on your skin, in excessive amounts it can cause irritation and redness. It is therefore important to use the rubbing alcohol only as directed by the instructions on the bottle.
Ethyl Alcohol Toxicity
Ethyl alcohol, also called ethanol, is toxic in many of the same ways as isopropyl alcohol. Ethanol causes severe irritation of the eyes accompanied by extreme sensitivity to light. If used excessively as rubbing alcohol, it can cause irritation and redness of the skin. It may even cause cyanosis, which is a condition characterized by a blue coloration of the skin, in your extremities.
Ingestion of ethanol causes nausea, diarrhea and vomiting. The system-wide toxicity that results from ethanol ingestion can cause acidosis of the blood and central nervous system depression characterized by excitement, followed by dizziness, drowsiness and nausea. This is the feeling of 'drunkenness' familiar to many people who drink alcoholic beverages.
Consumption of large quantities of ethanol leads eventually to collapse, coma and possibly death by respiratory failure. Chronic ingestion of ethanol causes fetal defects and liver damage. Lastly, inhalation of concentrated ethanol fumes also causes central nervous system effects. Respiratory irritation can be followed by nausea, dizziness, headache, unconsciousness and coma. Inhalation of extreme amounts of ethanol vapors can cause death by suffocation.
People commonly drink ethyl alcohol to become intoxicated. To prevent people from drinking ethanol-based rubbing alcohol, manufacturers add chemicals to make rubbing alcohol extremely bitter and undrinkable. These additives include sucrose octaacetate and denatonium benzoate. Neither chemical is toxic; indeed, small quantities of denatonium benzoate can be put on a child's thumb to prevent her from sucking it.