When comparing environmental releases and risks among various
screen reclamation technologies in the CTSA, we assumed that printers
were following all regulations and handling their wastes in a proper
manner. Which, among other things, meant that screen printers a) were
not releasing any waste from screen reclamation "down the drain" and
b) were not pouring excess solvent into their spent shop towels.
Contrary to what Marci said, we did not collect any information to
support those assumptions though they were used in the belief that this
was common industry practice.
The CTSA did address the laundering of shop towels used for screen
reclamation and found that, with the exception of one system, there
were no risks or concerns related to the commercial laundering of shop
towels used in screen reclamation. These was true even when
considering the cumulative releases among all the screen printing
facilities in a city (St. Louis was the example we used). These estimates
relate only to those towels used for screen reclamation, assume all
releases from laundering are treated by the POTW, and do not include
shop towels used for other purposes in a screen printing shop.