Xylene and Toluene
Xylene is a chemical that was commonly used in solvents and permanent marker ink. The largest problem with Xylene is that it is highly flammable. It is also mildly toxic.
Many of the marker pens on our site are Xylene-free and are labelled as such.
Toluene is another chemical which was commonly used in marker pens, glues and paint thinners along with many other products. Inhaling toluene can cause tiredness, confusion, nausea and loss of appetite. The symptons disappear when exposure is stopped in most cases.
For safety reasons, many marker manufacturers now make Toluene-free markers and many of those are on our website. Markers that contain toluene are usually fine in outdoor environments but if the markers are to be used for long periods of time indoors, you should definately consider using toluene-free products.