New alternatives, some of which are based on vegetable oil derivatives, are also being developed which may effectively remove inks from printing cylinders provided the ink is not allowed to dry out. When inks dry out on presses, significant cleaning problems arise. Some of these solvents have also been used as blanket revivers to swell low areas of the blanket. This depends on the particular solvent, to what extent the body is exposed to it and the way it enters the body, such as by breathing in and skin contact. Many solvents are also flammable and present significant fire hazards in use and storage.
Solvent vapour can travel long distances.
If enough vapour makes contact with a source of ignition, such as a hot surface, naked flame, or small sparks from static electricity, the resulting flashback and fire can be devastating. A fire hazard is also created by rags or cloths used during cleaning to wipe solvent across cylinders or other parts of presses. Other less volatile solvents such as white spirit present fire hazards because of their ease of combustion when exposed to a naked flame or other significant heat source. Suppliers of solvents have duties to provide health and safety information covering the hazards of their products. This is usually in the form of labels and safety data sheets.