title: Detection and characterization of nanomaterials released in low concentrations during multi-walled carbon nanotube spraying process in a cleanroom.
abstract: Release of nanomaterials was assessed in a cleanroom workplace designed for the handling of multi-walled carbon nanotubes. During the process, the nanotubes were sprayed in a chamber fitted with an exhaust duct system. The front door of the spraying chamber was completely closed, but rear end of the chamber was partially open. Throughout a series of spray processes, three detectors - an optical particle counter, a nanoparticle aerosol monitor, and an aethalometer - counted and characterized particles escaping the chamber. Concentrations of particle surface area and black carbon emitted by the spraying were assessed assuming zero background aerosol concentration in the cleanroom. Very low concentrations of black carbon, 0.4 μg/m(3), were observed. In conclusion, in a cleanroom, low concentrations of nanomaterials were detected to be emitted from a spraying chamber into the workplace. The level of particles reaching the workplace was sufficiently low to have made their detection difficult in a normal environment. Both target nanomaterial and non-intended incidental nanomaterials were released during spraying. Despite the use of exhaust duct system in the process chamber, workers would be exposed to some particles if the chamber were partially open. The exhaust duct system was not enough to remove all the particles released in the chamber.
authors.affiliation: Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology , Seoul, Korea .
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Ji
authors.forename: Daekwang
authors.initials: D
authors.lastname: Woo
authors.forename: Seung-Bok
authors.initials: SB
authors.lastname: Lee
authors.forename: Taesung
authors.initials: T
authors.lastname: Kim
authors.forename: Duckjong
authors.initials: D
authors.lastname: Kim
authors.forename: Jae-Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Gwi-Nam
authors.initials: GN
authors.lastname: Bae
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D002244:Carbon / Q000032:analysis; D004780:Environment, Controlled; D004784:Environmental Monitoring; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000032:analysis; D037742:Nanotubes, Carbon / Q000032:analysis* / Q000648:ultrastructure; D016273:Occupational Exposure / Q000032:analysis*; D010316:Particle Size; D013499:Surface Properties; D017132:Workplace
chemical_list: D000395:Air Pollutants, Occupational; D037742:Nanotubes, Carbon; D002244:Carbon