PBDEs emission from waste printed wiring boards during thermal process

Area of Science:

• Environmental Science
• Occupational Health
• Chemical Engineering

Background:

• Waste printed wiring boards (PWBs) contain polybrominated diphenyl ethers (PBDEs).
• Thermal processing of PWBs releases PBDEs into the air and dust.
• Occupational exposure to PBDEs is a concern in PWB recycling workshops.

Purpose of the Study:

• To investigate PBDEs emission mechanisms during PWB thermal processing.
• To quantify PBDEs concentrations in air and dust samples from a PWB-heating workshop.
• To compare PBDEs emission rates from PWB dust and fragments.

Main Methods:

• Air and dust sampling in a PWB-heating workshop.
• Laboratory heating experiments using a quartz tube furnace.
• Analysis of PBDEs concentrations and emission rates.

Main Results:

• Elevated PBDEs concentrations were found in workshop dust (up to 317,000 ng/g) compared to PWB waste (15,600 ng/g).
• PBDEs emission rates from dust were higher than from PWB fragments, especially within the first hour.
• PBDEs emission from dust occurred rapidly at 300°C, while PWB fragments showed a linear increase over time.

Conclusions:

• Thermal processing of PWB waste is a significant source of PBDE emissions.
• PBDEs in dust are more readily emitted than those in PWB fragments.
• Management strategies are crucial to reduce worker exposure to PBDEs in PWB recycling facilities.