Engineering Controls Database

Substitution of Cleaning Solutions in Printing Operations

Press operators and other workers in printing establishments are exposed to airborne solvent vapors generated when the press is cleaned. Press-cleaning solutions are generally a mixture of chemicals that include various solvents, some of which are carcinogens. Many of these solvents can be absorbed through the skin. Inks used in commercial printing are also potentially hazardous. In a study of printers’ inks, 29 samples of ink contained 46 different solvents in various combinations. Airborne exposures to hazardous chemicals are caused by evaporation from ink trays, rollers and blankets blending and thinning operations, and plate, blanket, screed, and press cleanup. Also, airborne particulates are generated by the printing process. The anti-offset powder used to prevent transfer of ink from the previous sheet to the back of the next sheet, typically made from corn or potato starch, has severe indices of ignition sensitivity and explosion severity, although the minimum explosive concentration (30±50 g/m3) is several orders of magnitude above the airborne concentrations expected in printing applications. Potato starch has a Class 2 flammability rating, characterized by local combustion of short duration.
Adverse health effects from inhalation of or skin contact with cleaning solutions include dermatitis, itchy eyes, headaches, nausea, vomiting, dizziness, respiratory failure, central nervous system depression, coughing, difficulty breathing, upper respiratory tract irritation, chest pains, unconsciousness, and death. Chronic effects may include kidney and liver damage, as well as cancer. The principal adverse health effect of the great majority of the cleaning compounds is narcosis. The anti-offset powder used, typically consisting of raw ground corn or potato starch, is a potential allergic sensitizer. After long-term exposure, allergies to this dust could develop into occupational asthma.
Cleaning solutions should not contain potential carcinogens. Printing processes can be modified so that solvents with less pollution potential, such as water- or oil-based solutions, are used in place of traditional cleaning solutions. This often reduces workers’ solvent exposure. Also, with the lowered Permissible Exposure Limit (PEL) for methylene chloride now at 25 parts per million, cleaners that are free of methylene chloride and water-based should be used.
205-12-A; 205-13-A;
323110
commercial printing
lithographic printing
press
press maintenance
press operators
printers
printing