Waste Blanket Wash — Watch Out for Your Wash
In order to reduce or eliminate this problem, there are three approaches that can be taken. The first would be to adjust the volume of solvent being applied to the blanket and training employees in how frequently the system should be cycled. By making adjustments to the volume being applied and training employees on proper applications, some printers have cut their waste volume in half.
Several other printers have been successful in replacing their current solvents with ones that are not classified as hazardous waste. These solvents need to have a flashpoint above 140°F and not contain any chemical that would be on one of the USEPA’s lists of “listed” hazardous wastes. In pursuing this approach, it is important to work with the vendor of your automatic blanket wash system to determine if they have any solvents that would not be classified as hazardous waste and ensure the solvents are compatible and approved for use in the system.
The drawback to this approach is that there is still a large volume of waste that must be properly disposed, which can be expensive. Switching to nonhazardous solvents in conjunction with a distillation unit can be a very powerful combination, as it will eliminate this hazardous waste stream and reduce costs.
If printers choose distillation units as the preferred method of waste reduction without changing to a non-hazardous solvent, they must realize that the regulations focus on the “point of generation” and the ability to change generator status is limited and depends upon how the waste is transferred from the press to the distillation unit.
When the distillation unit is hard piped from the press, then the only waste that gets counted toward determining generator classification is the waste generated by the distillation unit itself. If the waste blanket wash is hand-carried to the distillation unit and recovered, the entire volume of the waste is counted toward the generator classification. The good news is that once the waste is counted once during the month, it does not get recounted until the following month.