It’s well understood that torching scrap electronics – either through crude processing or accidental warehouse fires – releases harmful toxics. But testing supported by the U.S. EPA has now helped identify exactly which substances are emitted, and it found some previously undetected by researchers.
Using equipment from PerkinElmer, a Waltham, Mass.-based company specializing in imaging and detection technologies, scientists burned components of e-scrap so they could study how fast they broke down when they caught fire and what gases were emitted.
“The goal of this study is laboratory simulation of open burning practices that often accompany undeveloped e-waste recycling operations, and to provide information and exposure risks to these emissions,” according to a recently released document from PerkinElmer. “The data will be used to understand better what exposures and releases occur in e-waste processing and how can they be mitigated.”
Researchers burned material from used cellphones and laptops, including plastic cellphone and laptop casings, glass from devices and printed circuit boards. The testing took place in mid-2016 at PerkinElmer’s Shelton, Conn. testing center.
Jun Wang, senior application scientist for PerkinElmer, told E-Scrap News the testing revealed some toxic compounds researchers hadn’t previously found during previous tests, including aniline and N-methylaniline. Those were both fairly dominant compounds in the emitted gases, he said.
In addition to Wang, authors of the paper included officials from the U.S. EPA’s National Risk Management Research Laboratory (NRMRL) in Cincinnati and a University of Cincinnati chemical engineering student. The project manager was Dr. Endalkachew Sahle-Demessie, a senior scientist at the NRMRL.
This project was the first time three different pieces of equipment had been combined to study e-scrap burning, he said. The combination of three devices allowed for the analysis of more gases than during previous testing, during which only the lighter gases could be studied.
The first piece of equipment burned samples with a controlled temperature and atmosphere while analyzing the loss of weight. It quantified the thermal stability of different materials in electronics and provided a final weight of the residual char or ash. The second piece of equipment separated the emitted gases so they could be individually studied, while the third conducted the gas analysis.
“This is actually a new technique we’re using for this kind of application,” Wang said.
He acknowledged limitations inherent in lab testing, including the fact that they couldn’t study secondary reactions caused by gases interacting with each other. And the PerkinElmer document concluded that data is still limited.
“Much more still needs to be learned about the extent and long-term effects of these particular e-waste activities on environmental and human health,” it said.
While some of the gases detected in the testing are known or probable carcinogens, others haven’t been assessed, Wang said. Toxic compounds aren’t just dangerous during the burning of electronics; they can pollute soils and water bodies, leading to human exposure later.
A goal of the project is to create an awareness of toxics emitted from burning electronics so organizations can assess how dangerous they are. For example, the U.S. EPA has what it calls the Integrated Risk Information System (IRIS), providing data on the health hazards of chemicals. The research aims to help flesh out the IRIS list, he said.
Results of the project will be presented at the laboratory science conference and expo Pittcon, to be held this month in Chicago. The coordinators also plan to submit it to a peer-reviewed journal for publication, Wang said.