As the desktop computer made all of us publishers, the desktop 3-D printer promises to make us all manufacturers. But does that mean turning our home offices into smoggy factory floors?
This question caught the attention of Brent Stephens, an engineering professor at the Illinois Institute of Technology, when a student in his class on indoor air pollution told him he was concerned about the air quality at his job at a new 3-D printer shop.
"I basically said: ‘What is a 3-D printer?’" Stephens recalls.
Turning to the Internet, he and his students found, of course, plenty of articles (many in Make Magazine), but little that shed light on their academic bailiwick of emissions. "We did a basic literature search and couldn’t find anything on what had been measured," says Stephens.
They decided to fill that void, in a decidedly ad hoc fashion. They took a machine for measuring very small particles (less than 400 nanometers), wrapped it in towels, threw it in a duffel bag and took the subway to the 3-D printer shop. Then they ran various printers. "We just kind of closed the door, went to have some coffee, and came back and checked out the measurements," says Stephens.
The study’s attention-getting conclusion was that yes, desktop 3-D printers emit a lot of tiny "ultra-fine particles" (UFPs)—the number of such particles multiplied by 15 when all five 3-D printers were running. The question is if that big number (15 times!) is actually anything to worry about. "We found these to emit about the same number of particles as a lot of cooking activities," says Stephens. Other comparable sources of UFPs: running a laser printer and burning a candle.
So, UFPs: Nothing to worry about? It may depend on what those particles are actually composed of. Stephens cited a German study in which increased number of UFPs was associated with a higher mortality rate from respiratory disease, but the UFPs in question were basically diesel soot. The plastics used in 3-D printing vary, but Stephens says we won’t really know how safe they are until there are studies that check them directly.
But even cheaper than more studies are precautions. "A 3-D printer is basically another shop tool in my mind," says Stephens. "There’s a lot of tools like that, like saws or other machines, that we either filter their exhaust or we exhaust them to outdoors or we operate some enclosure or we wear some kind of protective gear like a mask."
As he points out, even when you cook on the stove, you probably use a range hood.