Ink Poisoning
While not always an immediate threat, ingested ink from Magic Markers can cause ink poisoning. The chemical xylene is a poisonous substance and the use of it in magic markers is the cause of ink poisoning. This type of poisoning is rarely fatal as the Magic Markers themselves have only a minute quantity of xylene and are considered nontoxic. A person's age, weight and other medical conditions affect the severity of the ink poisoning. Ink poisoning occurs when ink from a Magic Marker comes in contact with a person's eyes or mucous membrane. These surfaces will become irritated and it's recommended to get medical help as quickly as possible. Treatment in these instances usually involves washing the ink from the eyes and skin. If the ink has been swallowed, doctors advise against vomiting unless directed to by poison control or a health care professional.
Developing Allergies
The organic solvents in Magic Markers can lead to allergies. These allergies are slow building and occur over repeated exposure to Magic Marker ink. Even with no noticeable reaction to the organic solvents at first, after one exposure your skin already becomes sensitized to the chemicals and this sensitivity increases over time. Chemical sensitivity affects roughly 10 percent of the population at present, though those numbers may increase over time.
Fume Inhalation
Inhalation abuse is the greatest danger associated with permanent Magic Markers. In order to obtain a temporary high, people inhale the fumes created by the organic solvents in magic markers. The effect of marker inhalation is much the same as alcohol consumption. In the short term, the person feels giddy and inhibitions are lowered. In higher doses, marker inhalation can even cause hallucinations. Short-term side effects, including nausea, forgetfulness and blurred vision, last between 15 and 45 minutes after the fumes have been inhaled. The long-term effects are much more severe and include permanent damage to the brain, liver, kidneys and bone marrow, hearing loss, increased heart rate and spasms in the arms and legs. First time users also risk death from a condition called "sudden sniffing death." Pregnant women risk causing damage to their unborn babies in they inhale marker fumes while pregnant.